A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy lo...A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy loam (pH 4.5). Barley (Hondeum vulgare L. cv. Forrester) was used as a test crop and was grownin the sewage sludge-amended (33.5 t sludge DM ha-1) and unamended soils. The results showed that thealka1ine biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandyloam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg-1 for the former soil andfrom 4.0 to 0.1 cmol kg-1 for the latter soil. As a result, barley plants grew much better and grain yieldincreased greatly in the amended treatments compared with the unamended controls. These observationsindicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity instrongly acid soils by increasing soil pH and lowering Al bioavailability.展开更多
Illicit and pharmaceutical drugs are considered to be emerging contaminants of concern,and much research effort has gone into assessing their occurrence in wastewater.However,little information exists on their presenc...Illicit and pharmaceutical drugs are considered to be emerging contaminants of concern,and much research effort has gone into assessing their occurrence in wastewater.However,little information exists on their presence in treated sludge or biosolids.In this study,we examined sludge and biosolids from a large metropolitan wastewater treatment plant(WWTP)in Australia to determine the occurrence of five drugs of abuse,including benzoylecgonine as indicator of cocaine consumption,methamphetamine and 3,4-methylenedioxy methamphetamine(MDMA)as representative illicit stimulants,and codeine and morphine as pharmaceuticals with potential environmental risk.The samples were solid-phase extracted and analyzed by liquid chromatography–tandem mass spectrometry(LC–MS/MS).Benzoylecgonine and MDMA were present in raw sludge but were notably degraded during solids treatment processes,and were not detected in the dewatered sludge(after treatment)or in biosolids.Methamphetamine,codeine,and morphine were detected in all biosolids samples at mean concentrations of 20–50 lg kg^-1.The presence of these three drugs in biosolids shows that these compounds are relatively stable in the solids and in soil,and can persist in biosolids for at least several years.A simple environmental risk assessment based on estimated risk quotients(RQs)for these compounds indicated that the potential environmental risks associated with the land application of biosolids are very low at typical Australian biosolids application rates.展开更多
A field plot experiment in a calcareous soil with wheat and maize rotation was carried out for 2 yr. The study aimed to investigate the effects of biosolids （sewage sludge or chicken manure） application on nitrogen ...A field plot experiment in a calcareous soil with wheat and maize rotation was carried out for 2 yr. The study aimed to investigate the effects of biosolids （sewage sludge or chicken manure） application on nitrogen （N） and phosphorus （P） accumulation in soils and to develop a model for the effects of biosolids application on available P （Olsen-P） accumulation in soils, by which the quantities of biosolids that can be safely applied to agricultural soils were estimated. The results showed that heavy application of biosolids to agricultural soils based on the N requirement of a wheat-maize rotation cropping system will oversupply P. Soil total N was increased by 0.010 g kg-1 at application rate of 1 ton sewage sludge per hectare. The high ratio of N to P in grains of wheat and maize （from 4.0 to 7.6） and low ratio of N to P in biosolids （〈2） led to more surplus P accumulated in soils. Although plant yields and P uptake by plants increased with increasing quantities of applied biosolids in soils, there was still an average 2.87 mg kg-1 increase in Olsen-P in the plough layer treated with biosolids for every 100 kg P ha-1 surplus. A predictive model was developed based upon the initial Olsen-P in soils, P input rates, crop yield, soil pH, and cultivation time. From the model, it is suggested that sewage sludge could be applied to calcareous soils for 12 yr using the recommended application rate （9 tons ha-1 yr-1）. The field results will be helpful in achieving best management of biosolids application for agricultural production and environmental protection.展开更多
Background:Forest management practices(e.g.choice of stand density,fertilisation)are just as important in carbon(C)forestry as in other types of forestry and will affect the level of C sequestration and profitability....Background:Forest management practices(e.g.choice of stand density,fertilisation)are just as important in carbon(C)forestry as in other types of forestry and will affect the level of C sequestration and profitability.Because C stored in wood is approximately proportional to the product of its volume and density,it is necessary to account for both volume growth and wood density when assessing the effects of fertilisation on C sequestration in pine forests.Methods:The effects of nitrogen(N)input from biosolids application on forest C sequestration were quantified from an intensively monitored biosolids field trial in a Pinus radiata plantation on a sandy soil in New Zealand.The field trial tested the application of three biosolids rates:Control(no application),Standard(300 kg N⋅ha^(-1) applied every three years),and High(600 kg N⋅ha^(-1) applied every three years),across three levels of stand density:300,450,and 600 stems⋅ha^(-1).Carbon sequestration was estimated using the C-Change model from annual plot measurements of stand density,stem height and diameter,and annual breast height wood densities obtained from increment cores.Results:By age 24 years,N-fertilised trees had sequestered 40 t C⋅ha^(-1) more than unfertilised trees,an increase of 18%.Fertilisation increased stem volume by 23%but reduced stem wood density by 2.5%.Most of the increased C sequestration occurred between age 6 and age 17 years and the Standard rate gave the same increase in C sequestration as the High rate.On average,there was no significant difference in growth rate between fertilised and unfertilised trees after the 17th growth year,but the increased growth ceased earlier at higher stand densities,and later at lower stand densities.Conclusions:This study indicates that 2–3 applications of the Standard rate would have been sufficient to achieve the increased C sequestration,with an applied N to C conversion ratio of 43–65 kg C⋅kg^(-1) N.Our results highlight that N fertilisation will become more widespread under greenhouse gas emissions trading schemes which en-courages forest management practices that improve C sequestration in young forests in New Zealand in particular and other countries in general.展开更多
Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study wa...Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study was to determine the impact of chemical amendments on WEP （water-extractable phosphorus） in applied treatments and DRP （dissolved reactive phosphorus） in runoff from biosolids-amended soils. Rainfall simulations were conducted in 2006 on field plots fertilized with biosolids that had been treated with alum [（A12804）3＂ 14H20], ferric chloride （FeC13） or an alum-based WTR （water treatment residual） at a rate of 20% （wt/wt） to reduce DRP in runoff. In 2007, rainfall simulations were conducted using WTR/biosolid blends of 15% and 30% （wt/wt） that were allowed to incubate for three weeks prior to application. Cumulative DRP runoff load observed for the 20% WTR treatment was not significantly different from other chemical treatments and resulted in a 45% reduction in DRP runoff as compared to the untreated biosolids application. Cumulative DRP runoff load in 2007 for the 15% and 30% WTR treatments resulted in significantly lower DRP loads compared to untreated biosolids and led to DRP runoff load reductions of 78% and 85% （compared to the untreated biosolids application）, respectively.展开更多
The US is one of the leading global producers of paper industry with approximately 24 percent of the share of world paper supply. Despite diversity of the feedstock and production methods, C rich papermill biosolids (...The US is one of the leading global producers of paper industry with approximately 24 percent of the share of world paper supply. Despite diversity of the feedstock and production methods, C rich papermill biosolids (PB) is a major byproduct of paper production process. Landfilling is the predominant method of PB management. Increasing landfill cost and its potential environmental consequences have incentivized research and development efforts to find beneficial uses for PB. This sensible option reduces the overall paper production costs and increases environmental sustainability. Pelletization of PB increases its marketability by reducing transportation costs. This greenhouse study was conducted to gain a better understanding of the properties and effects of a recently developed pelletized papermill biosolids (PPB) on bell pepper (Capsicum annuum L.) and soil. Urea and PPB were each applied at four total N rates equivalent to 45, 90, 135, and 180 kg N ha﹣1 and an additional control treatments of 0 N was included. The total C and N concentration in this PPB were 379 and 14 g·kg﹣1 respectively and its C:N ratio was 27.2. Nitrogen treatment significantly (P ≤ 0.0839) influenced pepper height, dry biomass, N concentration, and N uptake. Plant height ranged from 31.2 to 44.4 cm;135 kg·ha﹣1 urea-N and PPB-N produced the tallest and shortest plants respectively. Dry biomass of the pepper that did not receive any N, those treated with urea-N or PPB-N were 5.3, 5.7 - 7.5, and 5.9 - 6.5 g·plant﹣1 respectively. Nitrogen concentration in control treatment (0 N) was 36.4 g·kg﹣1 and that of pepper treated with any N ranged from 32.0 - 40.7 g·kg﹣1. There was an inverse numerical, albeit not always statistically significant, relationship between PPB rate and plant N concentration. Generally, pepper treated with urea removed significantly more N from soil than control or PPB treated pepper. Nitrogen uptake by plants that did not receive any N and those amended with urea or PPB were 194, 229 - 270, and 155 - 164 mg·plant﹣1 respectively. Pepper N uptake and concentration data indicate that higher rates of PPB resulted in immobilization of native soil and PPB-N due to its wide C:N ratio (27.2). Nitrogen treatment significantly influenced soil pH, SOM, total C and N (P > 0.1). Soil organic matter and total C in post-harvest soil samples were 17.4 - 19.4 and 21.9 - 35.0 g·kg﹣1 respectively. The observed increase in soil total C and SOM highlights the potential beneficial use of PPB as a means to improve soil health and sequester C in soil. Narrowing the C:N ratio of PPB, by coapplication or incorporation of the mineral N into the pellets will make it an attractive organic N fertilizer.展开更多
Beneficial utilization of industrial byproducts such as papermill biosolids (PB) provides a unique opportunity to reduce the overall production cost and increase environmental sustainability. Pelletization of a byprod...Beneficial utilization of industrial byproducts such as papermill biosolids (PB) provides a unique opportunity to reduce the overall production cost and increase environmental sustainability. Pelletization of a byproduct enhances its marketability by improving the transportation and application. This greenhouse study was conducted to gain a better understanding of the properties and effects of, a recently developed pelletized papermill biosolids (PPB), on corn (Zea mays L.) and soil. Urea and PPB were each applied at four total N rates equivalent to 45, 90, 135, and 180 kg⋅ha−1 and an additional control treatments of 0 was also included. The PPB contained 379 and 14 g⋅kg−1 total N and C and its C:N ratio was 27. Nitrogen treatment significantly (P ⋅plant−1 where application of 180 kg⋅ha−1 of PPB-N produced the smallest plant biomass. Numerically the dry biomass of corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea was 38.3, 26.9 - 41.1 and 38.1 - 40.92 g⋅plant−1 respectively. Nitrogen concentration in corn plants ranged 6.2 - 11.5 g⋅kg−1. Nitrogen concentration in corn that did not receive any urea or corn that received urea was 8.7 - 11.5 g⋅kg−1 and was significantly more than corn treated with any PPB. Total N uptake (removed from soil) by the corn plant was 166 - 455 mg⋅plant−1. Total N uptake by corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea were 327, 166 - 278, and 379 - 455 mg⋅plant−1 respectively. The data suggest that the high C/N ratio (27.2) of PPB resulted in immobilization of PPB-N. Thus the next step will be to research the optimal rates of inorganic N that should be incorporated into this PPB to reduce its C:N to make it an effective high organic matter content N fertilizer. Nitrogen treatment significantly (P g⋅kg−1. The SOM of the treatments fertilized with 90 and 180 kg⋅ha−1 of PPB-N was 19.4 - 19.7 g⋅kg−1 and was significantly higher than soil that did not receive any N. The application of PPB significantly increased the soil total C which was 36.0 and 23.6 g⋅kg−1 in the soil amended with 180 kg⋅ha−1 of PPB-N and the control respectively. The observed increase in SOM and total C in PPB treated soil points to the potential soil health and C sequestration benefits of PPB provided that its C/N ratio can be increased by incorporating inorganic N into it.展开更多
Studies on the effects of biosolids(BS)amended substrate on food quality and safety in tomato production have not been adequately addressed.The objective of this study was to investigate the influence of composted BS ...Studies on the effects of biosolids(BS)amended substrate on food quality and safety in tomato production have not been adequately addressed.The objective of this study was to investigate the influence of composted BS and NPK fertilizer on post-harvest quality and safety of potted greenhouse tomato Solanum lycopersicum L.Potted tomatoes"Maxim F1"were grown in a randomized complete block design with four replications.Inorganic fertilizer NPK(17:17:17) fertilizer was applied at 0,100 kg ha^(-1)(5g per pot)and 200 kg ha^(-1);(10g per pot),BS was applied at 0%,10%,20%,30%,and 40%v/v,in all possible combinations.Tomato were harvested and analyzed for ascorbic acid,chlorophylls,carotenoids and total phenolic compounds;weight loss,fruit firmness,titratable acidity and total soluble solids,as well as heavy metals and microbial contaminants.Results revealed that tomato fruit at 10%BS in combination with NPK fertilizer at 100 kg ha^(-1) had the highestβ-carotene(6.1 mg 100 g^(-1)),lycopene(26.1 mg 100 g^(-1)),ascorbic acids(128.0 mg 100 g^(-1)),total phenolic acids(13.2 mg 100 g^(-1)),total soluble solids(17%).However,the same rates produced tomato fruit with lower titratable acidity(2.2%)and had heavy metal residues within the permissible level,according to International EPA standards on biosolids utilization for food crops production.Similarly,no trace of pathogenic bacteria;Salmonella,Escherichia coli,Staphylococcus was observed on the harvested tomato.This study reveals at BS 10% with NPK fertilizer at 100 kg ha^(-1) substrate as a better option of plant nutrient source for quality and safe greenhouse tomato production.展开更多
This paper proposes a methodology using computational fluid dynamics (CFD)</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style=...This paper proposes a methodology using computational fluid dynamics (CFD)</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">FLUENT to simulate the dispersion of particulate matter </span><span style="font-family:Verdana;">releasing</span><span style="font-family:Verdana;"> from a biosolid applied agricultural field and predict the particulate concentrations for different ranges of particle sizes. The discrete phase model</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">(</span><span style="font-family:Verdana;">Lagrangian</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Eulerian</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> approach) was used in combination with each of the four turbulence models:</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Standard </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;">), Realizable </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">),</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Standard </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">), and Shear-stress transport k-</span><i><span style="font-family:Verdana;">ω</span></i><span style="font-family:Verdana;"> (SST) to predict particulate matter size concentrations for distances downwind of the agricultural field.</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">In this modeling approach, particulates were simulated as discrete </span><span style="font-family:Verdana;">phase</span><span style="font-family:Verdana;"> and air as </span><span style="font-family:Verdana;">continuous</span> <span style="font-family:Verdana;">phase</span><span style="font-family:Verdana;">. The predicted particulate matter concentrations were compared statistically with their corresponding field study observations to evaluate the performance of turbulence models. The statistical analysis concluded that among four turbulence models, the discrete phase model when used with </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;"> performed the best in predicting particulate matter concentrations for low (</span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> < 2 m/s) and medium (2 < </span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> < 5 m/s) wind speeds. For high (</span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> > 5 m/s) wind speeds, </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">, and SST showed similar performances. The discrete phase model using </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;"> performed very well and modeled </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">best concentrations for the particle sizes (μm)</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> 0.23, 0.3, 0.4, 0.5, 0.65, 0.8, 1, 1.6, 2, 3, 4, and 5. For particle sizes</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> 7.5 and 10, the performances of </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">, and SST were simi</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">lar.展开更多
This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis p...This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis process patented by Lystek International Inc.(Cambridge,ON,Canada)to produce short-chain volatile fatty acids and other readily biodegradable organics.Two sequencing batch reactors(SBRs)were operated with synthetic volatile fatty acids(Syn VFA)and readily biodegradable organics produced from the alkaline hydrolysis of municipal wastewater biosolids(Lystek)as the carbon source,respectively.Municipal wastewaters with different strengths and COD:N:P ratios were tested in the study.The reactors’performances were compared with respect to nitrogen and phosphorus removal.It was observed that phosphorus removal efficiencies were between 98%–99%and 90%–97%and nitrogen removal efficiencies were 78%–81%,and 67%for the Syn VFA and Lystek,respectively.However,the kinetics for phosphorus release and uptake during the anaerobic and aerobic stages with Lystek were observed to be significantly lower than Syn VFA due to the presence of higher order VFAs(C4 and above)and other fermentable organics in the Lystek.展开更多
The effects of biosolids,ZnO,and ZnO/biosolids on soil microorganism and the environmental fate of coexisting racemic–quizalofop–ethyl(rac-QE)were investigated.Microbial biomass carbon in native soil,soil/biosolids ...The effects of biosolids,ZnO,and ZnO/biosolids on soil microorganism and the environmental fate of coexisting racemic–quizalofop–ethyl(rac-QE)were investigated.Microbial biomass carbon in native soil,soil/biosolids decreased by 62%and 52%in the presence of ZnO(2‰,weight ratio).The soil bacterial community structure differed significantly among native soil,soil/biosolids,soil/ZnO,and soil/biosolids/ZnO based on a principal co-ordinate analysis(PCo A)of OTUs and one-way ANOVA test of bacterial genera.Chemical transformation caused by ZnO only contributed 4%and 3% of the overall transformation of R-quizalofop-ethyl(R-QE)and S-quizalofop-ethyl(S-QE)in soil/ZnO.The inhibition effect of ZnO on the initial transformation rate of R-QE(rR-QE)and S-QE(rR-QE)in soil only observed when enantiomer concentration was larger than 10 mg/kg.Biosolids embedded with ZnO(biosolids/ZnO)caused a 17%–42% and 22%–38%decrease of rR-QE and rS-QE,although rR-QE and rS-QE increased by 0%–17% and 22%–58%by the addition of biosolids.The results also demonstrated that the effects of biosolids on agricultural soil microorganism and enantioselective transformation of chiral pesticide was altered by the embedded nanoparticles.展开更多
Emerging contaminants(ECs)represent a small fraction of the large chemical pollution puzzle where a wide variety of potentially hazardous chemicals reach the environment,and new compounds are continuously synthesized ...Emerging contaminants(ECs)represent a small fraction of the large chemical pollution puzzle where a wide variety of potentially hazardous chemicals reach the environment,and new compounds are continuously synthesized and released in wastewater treatment plants and ultimately in effluent and biosolids.ECs have been classified into various categories;however,this article focuses on the fate of major categories,namely pharmaceutical and personal care products(PPCPs),per-and poly-fluoroalkyl substances(PFAS),flame retardants,surfactants,endocrine-disrupting chemicals(EDCs),and microplastics(MPs).These ECs when discharged to sewer and downstream wastewater treatment plants can undergo further transformations and either degrade,persist or convert into by-products which have the potential in some cases to be more hazardous.Because of potential dangerous impacts of the availability of these contaminants in the environment,information on the fate and behavior of these pollutants is highly important to develop new strategies,such as the regulation of chemicals imported into Australia and Australian consumer goods and environmental policies to mitigate them in a sustainable way.Moreover,advanced technologies are required for the detection and identification of novel contaminants emerging in the environment at ultra low levels.The application of chromatographic techniques coupled with mass spectroscopy has provided attractive breakthroughs to detect new emerging contaminants.However,it is crucially important to understand the sensitivity and robustness of these analytical techniques when dealing with complex matrices such as biosolids.In addition,most of the literature was focused on selected compounds or a family of compounds and the existing reviews have paid less attention to examine the formation of metabolites during the wastewater treatment process and their impacts on the ecosystem.This review presents an overview of the presence of different classes of ECs around the world,their quantification from different sources like wastewater(influents or effluents),sludge and biosolids.In addition,the transformation of ECs during the treatment process,the formation of intermediate products and their impacts on the environment are also critically discussed.Three major steps of ECs analysis include sample preparation,extraction and clean-up,and analysis;hence,different methods employed for extraction and clean-up,and analytical techniques for identification are thoroughly discussed,their advantages and limitations are also highlighted.This comprehensive review article is believed to enhance the understanding of ECs in sewage sludge and would be useful to the readers of the relevant communities and various stakeholders to investigate potential technologies to maximize destruction of ECs.展开更多
This work investigates the influence of the type sludge on drainage, plant development, purification performances and biosolids quality. Drainage properties were measured through the frequency of clogging, the percent...This work investigates the influence of the type sludge on drainage, plant development, purification performances and biosolids quality. Drainage properties were measured through the frequency of clogging, the percentage of leachate recovered and the dryness of accumulated sludge. Plant development was measured through the density, the height and the stem diameter. Purification performance was evaluated from the reduction rate. Biosolids quality was measured after 3 months of maturation. The results show that the clogging frequencies were 9.5%;0% and 3.7%;the volume of leachate recovered was 42.2%;20.4% and 24.7% and, the dryness was 33.4%;61.1% and 52.4% for FS-ST, FS-STT and SS respectively. Plants densities were about, with densities 197.1, 171.3 and 178.3 plants/m2 in beds fed respectively with FS-ST, FS-STT and SS. Despite the high removal rates, the concentrations of pollutants in the leachates are above the Senegalese standard NS 05-061 for discharge into the environment. The biosolids are all mature with C/N and NH4+/NO3?ratios lower than 12 and 1 respectively. The biosolids are also rich in organic and mineral elements. The concentrations of Ascaris eggs are higher than the WHO recommendations. These biosolids should be stored for additional time or composted.展开更多
Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and ...Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.展开更多
In a greenhouse experiment we evaluated the application of slurry generated by a biogas reactor of agroindustrial residues. The objectives of this study were to determine the response to slurry application on dry matt...In a greenhouse experiment we evaluated the application of slurry generated by a biogas reactor of agroindustrial residues. The objectives of this study were to determine the response to slurry application on dry matter production and nutrients absorption of Setaria italica (setaria), and to evaluate the effect of the slurry on soil properties. Two soils, of different texture, were mixed either with slurry or with diammonium phofsphate (DAP) at 0, 80, and160 kgN ha-1 equivalent rates. The setaria was harvested 68 days after planting, and separated into leaves plus stems, ears, and roots. Total biomass and content of N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn were determined in each fraction. In the soil we determined pH, electric conductivity (EC), organic C, available P, mineral N, and exchangeable cations. Although the biomass produced and the amounts of nutrients absorbed were different in the two soils, in both of them setaria responded to the slurry application. The amounts of N absorbed from slurry and DAP were similar, indicating that the N from the slurry was readily available. The slurry application also increased the absorption of other macro and micro nutrients (P, Ca, Mg, and Zn). No significant changes in soil exchangeable cations, pH, and EC were observed at setaria harvest. In the silty soil the crop almost depleted the mineral N in all treatments, but in the sandy soil large amounts were left, especially in the treatments with slurry. This fact highlights the importance of a careful dosage of this soil amendment, to avoid the excess of mineral N, which is potential pollutant for the environment. It can be concluded that the use of slurry from the reactor had a positive effect on the nutrients availability, without negative effects on soil properties.展开更多
The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180...The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180,360,and720 Mg ha-1on a dry basis) were compared with trees grown in a reference nonfertilized area.Included in the study was a hybrid poplar(Populus tremula x Populus tremuloides) developed for use as an energy crop,three local tree species and one introduced tree species.The concentrations of Cd,Cr,Cu,Ni,Pb and Zn in the stemwood of the trees grown in the fertilized and nonfertilized fields were determined,and found to be significantly lower than their respective concentrations in the soil.Cd and Cr were found only in several wood samples at concentrations close to the limits of detection or qualification; therefore,they were not analyzed further.A correlation analysis suggested that 75%of the correlations between the concentrations of heavy metals in the stemwood and the concentrations in the soil were negative.The ability of trees to accumulate the metals from soil in most cases decreased for Cu and Ni; however,the correlations were not as clear for Pb and Zn.The followingsequence for the levels of heavy metals found in the stemwood of the analysed trees was Zn [ Pb [ Ni [ Cu [(Cr,Cd).The results of this study showed that the levels of heavy metals in the studied wood would not exceed the permitted limits of heavy metal pollution in the air and ash when used for energy production.展开更多
Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture...Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture experiment was conducted to study the effects of 130 mg N of either solids waste compost (Scomp) or biosolids waste compost (Bcomp) complemented with 130 mg (CF, 1N) and 260 mg·N·pot-1 (CF, 2N) as 15N labeled (NH4)2SO4 (13.172 atom %) on growth and N uptake by Italian ryegrass. A separate soil incubation without plants was set up by only blends of Scomp and CF. The results from pot culture experiment show that total plant biomass and N uptake from Bcomp were significantly higher than Scomp alone. Scomp combined with CF improved yield and N uptake over those of Scomp alone. For Scomp + 1N treatment, plant nitrogen uptake derived from compost and CF accounted for 29% and 56% of added N from Scomp and CF, respectively. The incubation study indicates that 16.08 - 29.62 mg·N·kg-1·soil·day-1 from inorganic-N were immobilized into organic pools, while only 0.40 - 0.66 mg·N·kg-1·soil·day-1 from organic-N were mineralized to inorganic pools. Because a part of additional N could be tied up in organic form, combining solids compost with chemical N fertilizer therefore need to consider the effective use of compost-N.展开更多
Phosphorus loading and measurement is of concern on lands where biosolids have been applied. Traditional soil testing for plant-available P may be inadequate for the accurate assessment of P loadings in a regulatory e...Phosphorus loading and measurement is of concern on lands where biosolids have been applied. Traditional soil testing for plant-available P may be inadequate for the accurate assessment of P loadings in a regulatory environment as the reported levels may not correlate well with environmental risk. In order to accurately assess potential P runoff and leaching, as well as plant uptake, we must be able to measure organic P mineralized by the biotic community in the soil. Soils with varying rates of biosolid application were evaluated for mineralized organic P during a 112-day incubation using the difference between P measured using a rapid-flow analyzer (RFA) and an axial flow Varian ICP-OES. An increase in the P mineralized from the treated soils was observed from analysis with the Varian ICP-OES, but not with the RFA. These results confirm that even though organic P concentrations have increased due to increasing biosolid application, traditional soil testing using an RFA for detection, would not accurately portray P concentration and potential P loading from treated soils.展开更多
In this study, Nitrogen leaching following surface application of biosolid with and without polyacrylamide (PAM) coating was investigated using soil column experiments. Three treatments including bare soil (C), a comm...In this study, Nitrogen leaching following surface application of biosolid with and without polyacrylamide (PAM) coating was investigated using soil column experiments. Three treatments including bare soil (C), a commercially available biosolid (BS) and PAM coated biosolid (PAM + BS), were applied to manually packed (bulk density: 1.3 g·cm-3) growth chamber soil columns (GC columns: 5 cm diameter by 40 cm long) and greenhouse soil columns (GH columns: 15 cm diameter by 40 cm long). The application rates for BS and PAM + BS were 729 and 740 kg/ha, respectively. The GC columns were incubated for 60 days in a dark chamber at 25℃ and no crop was grown in the columns. The GH columns were incubated for 60 days in a greenhouse and Ryegrass (seed rate: 252 kg/ha) was grown in these columns under 16 h daylight and at about 25℃. The columns were irrigated weekly using 270 mL DI-water for GC columns and 850 mL for GH columns and leachate was analyzed for Ammonium (NH4-N), Nitrate (NO3-N) and total Nitrogen (TN). The GH column experiments were repeated with three times greater biosolid application rate (2187 kg/ha) while keeping the PAM and Ryegrass seed rate constant. The leachate volume and NH4-N, NO3-N and TN concentration/load were not significantly different among the treatments for the GH columns but were significantly different during the incubation period. The same was true for GC columns with the exception of NO3-N and TN concentration/load which, overall, were higher for the BS and PAM + BS treatments than for the C treatment. In the beginning of the incubation, the leachate from all treatments (GC and GH) contained the highest NH4-N concentrations (>USEPA target level: 0.1 mg/L) and decreased, in some cases rapidly, to near zero. The NO3-N concentrations were highest in the middle of the incubation and greater than the USEPA target level (10 mg/L). The NO3-N concentrations were lower for cropped GH columns compared to GC columns due to NO3-N uptake by plants. The three fold increase in biosolid application rate did not increase NH4-N concentrations in leachate but did increase NO3-N and TN concentrations/loads in leachate on average 2.5 to 2.7 times. The non-significant differences among treatment means for NH4-N, NO3-N and TN concentrations/loads for the GH columns suggest that land application of biosolid (with or without PAM) to cropped silt loam landscapes at the rates considered may be safe within the context of groundwater pollution.展开更多
Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large...Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large number of soils are nowadays contaminated over widespread areas, posing a great threat to public health worldwide. Unlike organic pollutants, Pb and Cd do not undergo chemical or microbial breakdown and stay likely in site for longer duration after their release. Immobilization is an in-situ remediation technique that uses cost-effective soil amendments to reduce Pb and Cd availability in the contaminated soils. The Pb and Cd contamination in the soil environment is reviewed with focus on source enrichment, speciation and associated health risks, and immobilization options using various soil amendments. Commonly applied and emerging cost-effective soil amendments for Pb and Cd immobilization include phosphate compounds, liming, animal manure, biosolids, metal oxides, and biochar. These immobilizing agents could reduce the transfer of metal pollutants or residues to food web(plant uptake and leaching to subsurface water) and their long-term sustainability in heavy metal fixation needs further assessment.展开更多
基金National Natural Science Foundation of China(Nos.49831070 and 40125005)theNational Key Basic Research Support Foundation of China(No.G1999011807) the Jiangsu Provincial Foundation for Young Scientists(No.BQ98050).
文摘A pot experiment was catried out to study alleviation of soil acidity and Al toxicity by applying analkaline-stabilised sewage sludge product (biosolids) to an acid clay sandy loam (pH 5.7) and a strongly acidsandy loam (pH 4.5). Barley (Hondeum vulgare L. cv. Forrester) was used as a test crop and was grownin the sewage sludge-amended (33.5 t sludge DM ha-1) and unamended soils. The results showed that thealka1ine biosloids increased soil pH from 5.7 to 6.9 for the clay sandy loam and from 4.5 to 6.0 for the sandyloam. The sludge product decreased KCl-extractable Al from 0.1 to 0.0 cmol kg-1 for the former soil andfrom 4.0 to 0.1 cmol kg-1 for the latter soil. As a result, barley plants grew much better and grain yieldincreased greatly in the amended treatments compared with the unamended controls. These observationsindicate that alkaline-stabilised biosolids can be used as a liming material for remedying Al phytotoxicity instrongly acid soils by increasing soil pH and lowering Al bioavailability.
基金supported by an Australian Government Research Training Program (RTP) Scholarshipfinancial support of the Cooperative Research Center for Low Carbon Living Ltd. (RP2017 and RP2008) whose activeties are supported by the Cooperative Research Centers program, an Australian Government initiativethe South Australian Health Network for its financial support
文摘Illicit and pharmaceutical drugs are considered to be emerging contaminants of concern,and much research effort has gone into assessing their occurrence in wastewater.However,little information exists on their presence in treated sludge or biosolids.In this study,we examined sludge and biosolids from a large metropolitan wastewater treatment plant(WWTP)in Australia to determine the occurrence of five drugs of abuse,including benzoylecgonine as indicator of cocaine consumption,methamphetamine and 3,4-methylenedioxy methamphetamine(MDMA)as representative illicit stimulants,and codeine and morphine as pharmaceuticals with potential environmental risk.The samples were solid-phase extracted and analyzed by liquid chromatography–tandem mass spectrometry(LC–MS/MS).Benzoylecgonine and MDMA were present in raw sludge but were notably degraded during solids treatment processes,and were not detected in the dewatered sludge(after treatment)or in biosolids.Methamphetamine,codeine,and morphine were detected in all biosolids samples at mean concentrations of 20–50 lg kg^-1.The presence of these three drugs in biosolids shows that these compounds are relatively stable in the solids and in soil,and can persist in biosolids for at least several years.A simple environmental risk assessment based on estimated risk quotients(RQs)for these compounds indicated that the potential environmental risks associated with the land application of biosolids are very low at typical Australian biosolids application rates.
基金the National Natural Science Foundation of China (30971868)the Beijing Drainage Group Co. Ltd., China
文摘A field plot experiment in a calcareous soil with wheat and maize rotation was carried out for 2 yr. The study aimed to investigate the effects of biosolids （sewage sludge or chicken manure） application on nitrogen （N） and phosphorus （P） accumulation in soils and to develop a model for the effects of biosolids application on available P （Olsen-P） accumulation in soils, by which the quantities of biosolids that can be safely applied to agricultural soils were estimated. The results showed that heavy application of biosolids to agricultural soils based on the N requirement of a wheat-maize rotation cropping system will oversupply P. Soil total N was increased by 0.010 g kg-1 at application rate of 1 ton sewage sludge per hectare. The high ratio of N to P in grains of wheat and maize （from 4.0 to 7.6） and low ratio of N to P in biosolids （〈2） led to more surplus P accumulated in soils. Although plant yields and P uptake by plants increased with increasing quantities of applied biosolids in soils, there was still an average 2.87 mg kg-1 increase in Olsen-P in the plough layer treated with biosolids for every 100 kg P ha-1 surplus. A predictive model was developed based upon the initial Olsen-P in soils, P input rates, crop yield, soil pH, and cultivation time. From the model, it is suggested that sewage sludge could be applied to calcareous soils for 12 yr using the recommended application rate （9 tons ha-1 yr-1）. The field results will be helpful in achieving best management of biosolids application for agricultural production and environmental protection.
基金The Ministry of Business,Innovation and Employment,New Zealand provided funding(contract no.C03X0902)for this research.
文摘Background:Forest management practices(e.g.choice of stand density,fertilisation)are just as important in carbon(C)forestry as in other types of forestry and will affect the level of C sequestration and profitability.Because C stored in wood is approximately proportional to the product of its volume and density,it is necessary to account for both volume growth and wood density when assessing the effects of fertilisation on C sequestration in pine forests.Methods:The effects of nitrogen(N)input from biosolids application on forest C sequestration were quantified from an intensively monitored biosolids field trial in a Pinus radiata plantation on a sandy soil in New Zealand.The field trial tested the application of three biosolids rates:Control(no application),Standard(300 kg N⋅ha^(-1) applied every three years),and High(600 kg N⋅ha^(-1) applied every three years),across three levels of stand density:300,450,and 600 stems⋅ha^(-1).Carbon sequestration was estimated using the C-Change model from annual plot measurements of stand density,stem height and diameter,and annual breast height wood densities obtained from increment cores.Results:By age 24 years,N-fertilised trees had sequestered 40 t C⋅ha^(-1) more than unfertilised trees,an increase of 18%.Fertilisation increased stem volume by 23%but reduced stem wood density by 2.5%.Most of the increased C sequestration occurred between age 6 and age 17 years and the Standard rate gave the same increase in C sequestration as the High rate.On average,there was no significant difference in growth rate between fertilised and unfertilised trees after the 17th growth year,but the increased growth ceased earlier at higher stand densities,and later at lower stand densities.Conclusions:This study indicates that 2–3 applications of the Standard rate would have been sufficient to achieve the increased C sequestration,with an applied N to C conversion ratio of 43–65 kg C⋅kg^(-1) N.Our results highlight that N fertilisation will become more widespread under greenhouse gas emissions trading schemes which en-courages forest management practices that improve C sequestration in young forests in New Zealand in particular and other countries in general.
文摘Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study was to determine the impact of chemical amendments on WEP （water-extractable phosphorus） in applied treatments and DRP （dissolved reactive phosphorus） in runoff from biosolids-amended soils. Rainfall simulations were conducted in 2006 on field plots fertilized with biosolids that had been treated with alum [（A12804）3＂ 14H20], ferric chloride （FeC13） or an alum-based WTR （water treatment residual） at a rate of 20% （wt/wt） to reduce DRP in runoff. In 2007, rainfall simulations were conducted using WTR/biosolid blends of 15% and 30% （wt/wt） that were allowed to incubate for three weeks prior to application. Cumulative DRP runoff load observed for the 20% WTR treatment was not significantly different from other chemical treatments and resulted in a 45% reduction in DRP runoff as compared to the untreated biosolids application. Cumulative DRP runoff load in 2007 for the 15% and 30% WTR treatments resulted in significantly lower DRP loads compared to untreated biosolids and led to DRP runoff load reductions of 78% and 85% （compared to the untreated biosolids application）, respectively.
文摘The US is one of the leading global producers of paper industry with approximately 24 percent of the share of world paper supply. Despite diversity of the feedstock and production methods, C rich papermill biosolids (PB) is a major byproduct of paper production process. Landfilling is the predominant method of PB management. Increasing landfill cost and its potential environmental consequences have incentivized research and development efforts to find beneficial uses for PB. This sensible option reduces the overall paper production costs and increases environmental sustainability. Pelletization of PB increases its marketability by reducing transportation costs. This greenhouse study was conducted to gain a better understanding of the properties and effects of a recently developed pelletized papermill biosolids (PPB) on bell pepper (Capsicum annuum L.) and soil. Urea and PPB were each applied at four total N rates equivalent to 45, 90, 135, and 180 kg N ha﹣1 and an additional control treatments of 0 N was included. The total C and N concentration in this PPB were 379 and 14 g·kg﹣1 respectively and its C:N ratio was 27.2. Nitrogen treatment significantly (P ≤ 0.0839) influenced pepper height, dry biomass, N concentration, and N uptake. Plant height ranged from 31.2 to 44.4 cm;135 kg·ha﹣1 urea-N and PPB-N produced the tallest and shortest plants respectively. Dry biomass of the pepper that did not receive any N, those treated with urea-N or PPB-N were 5.3, 5.7 - 7.5, and 5.9 - 6.5 g·plant﹣1 respectively. Nitrogen concentration in control treatment (0 N) was 36.4 g·kg﹣1 and that of pepper treated with any N ranged from 32.0 - 40.7 g·kg﹣1. There was an inverse numerical, albeit not always statistically significant, relationship between PPB rate and plant N concentration. Generally, pepper treated with urea removed significantly more N from soil than control or PPB treated pepper. Nitrogen uptake by plants that did not receive any N and those amended with urea or PPB were 194, 229 - 270, and 155 - 164 mg·plant﹣1 respectively. Pepper N uptake and concentration data indicate that higher rates of PPB resulted in immobilization of native soil and PPB-N due to its wide C:N ratio (27.2). Nitrogen treatment significantly influenced soil pH, SOM, total C and N (P > 0.1). Soil organic matter and total C in post-harvest soil samples were 17.4 - 19.4 and 21.9 - 35.0 g·kg﹣1 respectively. The observed increase in soil total C and SOM highlights the potential beneficial use of PPB as a means to improve soil health and sequester C in soil. Narrowing the C:N ratio of PPB, by coapplication or incorporation of the mineral N into the pellets will make it an attractive organic N fertilizer.
文摘Beneficial utilization of industrial byproducts such as papermill biosolids (PB) provides a unique opportunity to reduce the overall production cost and increase environmental sustainability. Pelletization of a byproduct enhances its marketability by improving the transportation and application. This greenhouse study was conducted to gain a better understanding of the properties and effects of, a recently developed pelletized papermill biosolids (PPB), on corn (Zea mays L.) and soil. Urea and PPB were each applied at four total N rates equivalent to 45, 90, 135, and 180 kg⋅ha−1 and an additional control treatments of 0 was also included. The PPB contained 379 and 14 g⋅kg−1 total N and C and its C:N ratio was 27. Nitrogen treatment significantly (P ⋅plant−1 where application of 180 kg⋅ha−1 of PPB-N produced the smallest plant biomass. Numerically the dry biomass of corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea was 38.3, 26.9 - 41.1 and 38.1 - 40.92 g⋅plant−1 respectively. Nitrogen concentration in corn plants ranged 6.2 - 11.5 g⋅kg−1. Nitrogen concentration in corn that did not receive any urea or corn that received urea was 8.7 - 11.5 g⋅kg−1 and was significantly more than corn treated with any PPB. Total N uptake (removed from soil) by the corn plant was 166 - 455 mg⋅plant−1. Total N uptake by corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea were 327, 166 - 278, and 379 - 455 mg⋅plant−1 respectively. The data suggest that the high C/N ratio (27.2) of PPB resulted in immobilization of PPB-N. Thus the next step will be to research the optimal rates of inorganic N that should be incorporated into this PPB to reduce its C:N to make it an effective high organic matter content N fertilizer. Nitrogen treatment significantly (P g⋅kg−1. The SOM of the treatments fertilized with 90 and 180 kg⋅ha−1 of PPB-N was 19.4 - 19.7 g⋅kg−1 and was significantly higher than soil that did not receive any N. The application of PPB significantly increased the soil total C which was 36.0 and 23.6 g⋅kg−1 in the soil amended with 180 kg⋅ha−1 of PPB-N and the control respectively. The observed increase in SOM and total C in PPB treated soil points to the potential soil health and C sequestration benefits of PPB provided that its C/N ratio can be increased by incorporating inorganic N into it.
文摘Studies on the effects of biosolids(BS)amended substrate on food quality and safety in tomato production have not been adequately addressed.The objective of this study was to investigate the influence of composted BS and NPK fertilizer on post-harvest quality and safety of potted greenhouse tomato Solanum lycopersicum L.Potted tomatoes"Maxim F1"were grown in a randomized complete block design with four replications.Inorganic fertilizer NPK(17:17:17) fertilizer was applied at 0,100 kg ha^(-1)(5g per pot)and 200 kg ha^(-1);(10g per pot),BS was applied at 0%,10%,20%,30%,and 40%v/v,in all possible combinations.Tomato were harvested and analyzed for ascorbic acid,chlorophylls,carotenoids and total phenolic compounds;weight loss,fruit firmness,titratable acidity and total soluble solids,as well as heavy metals and microbial contaminants.Results revealed that tomato fruit at 10%BS in combination with NPK fertilizer at 100 kg ha^(-1) had the highestβ-carotene(6.1 mg 100 g^(-1)),lycopene(26.1 mg 100 g^(-1)),ascorbic acids(128.0 mg 100 g^(-1)),total phenolic acids(13.2 mg 100 g^(-1)),total soluble solids(17%).However,the same rates produced tomato fruit with lower titratable acidity(2.2%)and had heavy metal residues within the permissible level,according to International EPA standards on biosolids utilization for food crops production.Similarly,no trace of pathogenic bacteria;Salmonella,Escherichia coli,Staphylococcus was observed on the harvested tomato.This study reveals at BS 10% with NPK fertilizer at 100 kg ha^(-1) substrate as a better option of plant nutrient source for quality and safe greenhouse tomato production.
文摘This paper proposes a methodology using computational fluid dynamics (CFD)</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">FLUENT to simulate the dispersion of particulate matter </span><span style="font-family:Verdana;">releasing</span><span style="font-family:Verdana;"> from a biosolid applied agricultural field and predict the particulate concentrations for different ranges of particle sizes. The discrete phase model</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">(</span><span style="font-family:Verdana;">Lagrangian</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Eulerian</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> approach) was used in combination with each of the four turbulence models:</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Standard </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;">), Realizable </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">),</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Standard </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">), and Shear-stress transport k-</span><i><span style="font-family:Verdana;">ω</span></i><span style="font-family:Verdana;"> (SST) to predict particulate matter size concentrations for distances downwind of the agricultural field.</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">In this modeling approach, particulates were simulated as discrete </span><span style="font-family:Verdana;">phase</span><span style="font-family:Verdana;"> and air as </span><span style="font-family:Verdana;">continuous</span> <span style="font-family:Verdana;">phase</span><span style="font-family:Verdana;">. The predicted particulate matter concentrations were compared statistically with their corresponding field study observations to evaluate the performance of turbulence models. The statistical analysis concluded that among four turbulence models, the discrete phase model when used with </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;"> performed the best in predicting particulate matter concentrations for low (</span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> < 2 m/s) and medium (2 < </span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> < 5 m/s) wind speeds. For high (</span><i><span style="font-family:Verdana;">u</span></i><span style="font-family:Verdana;"> > 5 m/s) wind speeds, </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">, and SST showed similar performances. The discrete phase model using </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;"> performed very well and modeled </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">best concentrations for the particle sizes (μm)</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> 0.23, 0.3, 0.4, 0.5, 0.65, 0.8, 1, 1.6, 2, 3, 4, and 5. For particle sizes</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">:</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> 7.5 and 10, the performances of </span><i><span style="font-family:Verdana;">Rkε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kε</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">kω</span></i><span style="font-family:Verdana;">, and SST were simi</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">lar.
基金financial support from the Natural Sciences and Engineering Research Council of Canada
文摘This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis process patented by Lystek International Inc.(Cambridge,ON,Canada)to produce short-chain volatile fatty acids and other readily biodegradable organics.Two sequencing batch reactors(SBRs)were operated with synthetic volatile fatty acids(Syn VFA)and readily biodegradable organics produced from the alkaline hydrolysis of municipal wastewater biosolids(Lystek)as the carbon source,respectively.Municipal wastewaters with different strengths and COD:N:P ratios were tested in the study.The reactors’performances were compared with respect to nitrogen and phosphorus removal.It was observed that phosphorus removal efficiencies were between 98%–99%and 90%–97%and nitrogen removal efficiencies were 78%–81%,and 67%for the Syn VFA and Lystek,respectively.However,the kinetics for phosphorus release and uptake during the anaerobic and aerobic stages with Lystek were observed to be significantly lower than Syn VFA due to the presence of higher order VFAs(C4 and above)and other fermentable organics in the Lystek.
基金supported by the National Natural Science Foundation of China(No.21477091)
文摘The effects of biosolids,ZnO,and ZnO/biosolids on soil microorganism and the environmental fate of coexisting racemic–quizalofop–ethyl(rac-QE)were investigated.Microbial biomass carbon in native soil,soil/biosolids decreased by 62%and 52%in the presence of ZnO(2‰,weight ratio).The soil bacterial community structure differed significantly among native soil,soil/biosolids,soil/ZnO,and soil/biosolids/ZnO based on a principal co-ordinate analysis(PCo A)of OTUs and one-way ANOVA test of bacterial genera.Chemical transformation caused by ZnO only contributed 4%and 3% of the overall transformation of R-quizalofop-ethyl(R-QE)and S-quizalofop-ethyl(S-QE)in soil/ZnO.The inhibition effect of ZnO on the initial transformation rate of R-QE(rR-QE)and S-QE(rR-QE)in soil only observed when enantiomer concentration was larger than 10 mg/kg.Biosolids embedded with ZnO(biosolids/ZnO)caused a 17%–42% and 22%–38%decrease of rR-QE and rS-QE,although rR-QE and rS-QE increased by 0%–17% and 22%–58%by the addition of biosolids.The results also demonstrated that the effects of biosolids on agricultural soil microorganism and enantioselective transformation of chiral pesticide was altered by the embedded nanoparticles.
文摘Emerging contaminants(ECs)represent a small fraction of the large chemical pollution puzzle where a wide variety of potentially hazardous chemicals reach the environment,and new compounds are continuously synthesized and released in wastewater treatment plants and ultimately in effluent and biosolids.ECs have been classified into various categories;however,this article focuses on the fate of major categories,namely pharmaceutical and personal care products(PPCPs),per-and poly-fluoroalkyl substances(PFAS),flame retardants,surfactants,endocrine-disrupting chemicals(EDCs),and microplastics(MPs).These ECs when discharged to sewer and downstream wastewater treatment plants can undergo further transformations and either degrade,persist or convert into by-products which have the potential in some cases to be more hazardous.Because of potential dangerous impacts of the availability of these contaminants in the environment,information on the fate and behavior of these pollutants is highly important to develop new strategies,such as the regulation of chemicals imported into Australia and Australian consumer goods and environmental policies to mitigate them in a sustainable way.Moreover,advanced technologies are required for the detection and identification of novel contaminants emerging in the environment at ultra low levels.The application of chromatographic techniques coupled with mass spectroscopy has provided attractive breakthroughs to detect new emerging contaminants.However,it is crucially important to understand the sensitivity and robustness of these analytical techniques when dealing with complex matrices such as biosolids.In addition,most of the literature was focused on selected compounds or a family of compounds and the existing reviews have paid less attention to examine the formation of metabolites during the wastewater treatment process and their impacts on the ecosystem.This review presents an overview of the presence of different classes of ECs around the world,their quantification from different sources like wastewater(influents or effluents),sludge and biosolids.In addition,the transformation of ECs during the treatment process,the formation of intermediate products and their impacts on the environment are also critically discussed.Three major steps of ECs analysis include sample preparation,extraction and clean-up,and analysis;hence,different methods employed for extraction and clean-up,and analytical techniques for identification are thoroughly discussed,their advantages and limitations are also highlighted.This comprehensive review article is believed to enhance the understanding of ECs in sewage sludge and would be useful to the readers of the relevant communities and various stakeholders to investigate potential technologies to maximize destruction of ECs.
文摘This work investigates the influence of the type sludge on drainage, plant development, purification performances and biosolids quality. Drainage properties were measured through the frequency of clogging, the percentage of leachate recovered and the dryness of accumulated sludge. Plant development was measured through the density, the height and the stem diameter. Purification performance was evaluated from the reduction rate. Biosolids quality was measured after 3 months of maturation. The results show that the clogging frequencies were 9.5%;0% and 3.7%;the volume of leachate recovered was 42.2%;20.4% and 24.7% and, the dryness was 33.4%;61.1% and 52.4% for FS-ST, FS-STT and SS respectively. Plants densities were about, with densities 197.1, 171.3 and 178.3 plants/m2 in beds fed respectively with FS-ST, FS-STT and SS. Despite the high removal rates, the concentrations of pollutants in the leachates are above the Senegalese standard NS 05-061 for discharge into the environment. The biosolids are all mature with C/N and NH4+/NO3?ratios lower than 12 and 1 respectively. The biosolids are also rich in organic and mineral elements. The concentrations of Ascaris eggs are higher than the WHO recommendations. These biosolids should be stored for additional time or composted.
文摘Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.
文摘In a greenhouse experiment we evaluated the application of slurry generated by a biogas reactor of agroindustrial residues. The objectives of this study were to determine the response to slurry application on dry matter production and nutrients absorption of Setaria italica (setaria), and to evaluate the effect of the slurry on soil properties. Two soils, of different texture, were mixed either with slurry or with diammonium phofsphate (DAP) at 0, 80, and160 kgN ha-1 equivalent rates. The setaria was harvested 68 days after planting, and separated into leaves plus stems, ears, and roots. Total biomass and content of N, P, K, Ca, Mg, Cu, Fe, Mn, and Zn were determined in each fraction. In the soil we determined pH, electric conductivity (EC), organic C, available P, mineral N, and exchangeable cations. Although the biomass produced and the amounts of nutrients absorbed were different in the two soils, in both of them setaria responded to the slurry application. The amounts of N absorbed from slurry and DAP were similar, indicating that the N from the slurry was readily available. The slurry application also increased the absorption of other macro and micro nutrients (P, Ca, Mg, and Zn). No significant changes in soil exchangeable cations, pH, and EC were observed at setaria harvest. In the silty soil the crop almost depleted the mineral N in all treatments, but in the sandy soil large amounts were left, especially in the treatments with slurry. This fact highlights the importance of a careful dosage of this soil amendment, to avoid the excess of mineral N, which is potential pollutant for the environment. It can be concluded that the use of slurry from the reactor had a positive effect on the nutrients availability, without negative effects on soil properties.
文摘The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180,360,and720 Mg ha-1on a dry basis) were compared with trees grown in a reference nonfertilized area.Included in the study was a hybrid poplar(Populus tremula x Populus tremuloides) developed for use as an energy crop,three local tree species and one introduced tree species.The concentrations of Cd,Cr,Cu,Ni,Pb and Zn in the stemwood of the trees grown in the fertilized and nonfertilized fields were determined,and found to be significantly lower than their respective concentrations in the soil.Cd and Cr were found only in several wood samples at concentrations close to the limits of detection or qualification; therefore,they were not analyzed further.A correlation analysis suggested that 75%of the correlations between the concentrations of heavy metals in the stemwood and the concentrations in the soil were negative.The ability of trees to accumulate the metals from soil in most cases decreased for Cu and Ni; however,the correlations were not as clear for Pb and Zn.The followingsequence for the levels of heavy metals found in the stemwood of the analysed trees was Zn [ Pb [ Ni [ Cu [(Cr,Cd).The results of this study showed that the levels of heavy metals in the studied wood would not exceed the permitted limits of heavy metal pollution in the air and ash when used for energy production.
文摘Combining compost with sufficient chemical N fertilizer (CF) in agricultural lands is a popular practice to reduce the amount of inorganic nitrogen and accumulation of non-nutrient constituents in soils. A pot culture experiment was conducted to study the effects of 130 mg N of either solids waste compost (Scomp) or biosolids waste compost (Bcomp) complemented with 130 mg (CF, 1N) and 260 mg·N·pot-1 (CF, 2N) as 15N labeled (NH4)2SO4 (13.172 atom %) on growth and N uptake by Italian ryegrass. A separate soil incubation without plants was set up by only blends of Scomp and CF. The results from pot culture experiment show that total plant biomass and N uptake from Bcomp were significantly higher than Scomp alone. Scomp combined with CF improved yield and N uptake over those of Scomp alone. For Scomp + 1N treatment, plant nitrogen uptake derived from compost and CF accounted for 29% and 56% of added N from Scomp and CF, respectively. The incubation study indicates that 16.08 - 29.62 mg·N·kg-1·soil·day-1 from inorganic-N were immobilized into organic pools, while only 0.40 - 0.66 mg·N·kg-1·soil·day-1 from organic-N were mineralized to inorganic pools. Because a part of additional N could be tied up in organic form, combining solids compost with chemical N fertilizer therefore need to consider the effective use of compost-N.
文摘Phosphorus loading and measurement is of concern on lands where biosolids have been applied. Traditional soil testing for plant-available P may be inadequate for the accurate assessment of P loadings in a regulatory environment as the reported levels may not correlate well with environmental risk. In order to accurately assess potential P runoff and leaching, as well as plant uptake, we must be able to measure organic P mineralized by the biotic community in the soil. Soils with varying rates of biosolid application were evaluated for mineralized organic P during a 112-day incubation using the difference between P measured using a rapid-flow analyzer (RFA) and an axial flow Varian ICP-OES. An increase in the P mineralized from the treated soils was observed from analysis with the Varian ICP-OES, but not with the RFA. These results confirm that even though organic P concentrations have increased due to increasing biosolid application, traditional soil testing using an RFA for detection, would not accurately portray P concentration and potential P loading from treated soils.
文摘In this study, Nitrogen leaching following surface application of biosolid with and without polyacrylamide (PAM) coating was investigated using soil column experiments. Three treatments including bare soil (C), a commercially available biosolid (BS) and PAM coated biosolid (PAM + BS), were applied to manually packed (bulk density: 1.3 g·cm-3) growth chamber soil columns (GC columns: 5 cm diameter by 40 cm long) and greenhouse soil columns (GH columns: 15 cm diameter by 40 cm long). The application rates for BS and PAM + BS were 729 and 740 kg/ha, respectively. The GC columns were incubated for 60 days in a dark chamber at 25℃ and no crop was grown in the columns. The GH columns were incubated for 60 days in a greenhouse and Ryegrass (seed rate: 252 kg/ha) was grown in these columns under 16 h daylight and at about 25℃. The columns were irrigated weekly using 270 mL DI-water for GC columns and 850 mL for GH columns and leachate was analyzed for Ammonium (NH4-N), Nitrate (NO3-N) and total Nitrogen (TN). The GH column experiments were repeated with three times greater biosolid application rate (2187 kg/ha) while keeping the PAM and Ryegrass seed rate constant. The leachate volume and NH4-N, NO3-N and TN concentration/load were not significantly different among the treatments for the GH columns but were significantly different during the incubation period. The same was true for GC columns with the exception of NO3-N and TN concentration/load which, overall, were higher for the BS and PAM + BS treatments than for the C treatment. In the beginning of the incubation, the leachate from all treatments (GC and GH) contained the highest NH4-N concentrations (>USEPA target level: 0.1 mg/L) and decreased, in some cases rapidly, to near zero. The NO3-N concentrations were highest in the middle of the incubation and greater than the USEPA target level (10 mg/L). The NO3-N concentrations were lower for cropped GH columns compared to GC columns due to NO3-N uptake by plants. The three fold increase in biosolid application rate did not increase NH4-N concentrations in leachate but did increase NO3-N and TN concentrations/loads in leachate on average 2.5 to 2.7 times. The non-significant differences among treatment means for NH4-N, NO3-N and TN concentrations/loads for the GH columns suggest that land application of biosolid (with or without PAM) to cropped silt loam landscapes at the rates considered may be safe within the context of groundwater pollution.
文摘Since the inception of industrial revolution, metal refining plants using pyrometallurgical processes have generated the prodigious emissions of lead(Pb) and cadmium(Cd). As the core target of such pollutants, a large number of soils are nowadays contaminated over widespread areas, posing a great threat to public health worldwide. Unlike organic pollutants, Pb and Cd do not undergo chemical or microbial breakdown and stay likely in site for longer duration after their release. Immobilization is an in-situ remediation technique that uses cost-effective soil amendments to reduce Pb and Cd availability in the contaminated soils. The Pb and Cd contamination in the soil environment is reviewed with focus on source enrichment, speciation and associated health risks, and immobilization options using various soil amendments. Commonly applied and emerging cost-effective soil amendments for Pb and Cd immobilization include phosphate compounds, liming, animal manure, biosolids, metal oxides, and biochar. These immobilizing agents could reduce the transfer of metal pollutants or residues to food web(plant uptake and leaching to subsurface water) and their long-term sustainability in heavy metal fixation needs further assessment.
