Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficult...Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.展开更多
The overall purpose of this research is to examine the impact of untreated sedimentation tank sludge water( USTSW) recycle on water quality during treatment of low turbidity water in coagulation—sedimentation process...The overall purpose of this research is to examine the impact of untreated sedimentation tank sludge water( USTSW) recycle on water quality during treatment of low turbidity water in coagulation—sedimentation processes. 950 m L of raw water and different concentrations of 50 m L USTSW are injected into six 1 000 m L beakers without coagulant.The results indicate that USTSW characterized as accumulated suspended solids and organic matter has active ingredients,which possess the equivalent function of coagulant. The optimal blended water turbidity is in the range of 10-20 NTU,within which USTSW recycle achieves the highest save coagulant rate. The mechanism of strengthening coagulation effect when USTSW recycle mainly depends on the chemical effect and physical effect. What is more,through scanning electron microscopy( SEM),it is found that the floc structures with USTSW recycle are more compact than those without USTSW recycle. Besides,the water quality parameters of color,NH3-N,CODMn,UV254,total aluminum,total manganese when USTSW recycle is better than the raw water without recycle,indicating that USTSW recycle can improve water quality with strengthening coagulation effect.展开更多
基金supported by the Ministry of Science and Technology of China (Nos.2021YFC3200904,and 2022YFC3203705)the National Natural Science Foundation of China (Nos.52070184,and 52270012)the Nanning Scientific Research and Technology Development Project (No.ZC20223238).
文摘Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.
基金Sponsored by the Major Science and Technology Program for Water Pollution Control and Treatment(Grant No.2012ZX07408001,2014AX07405002)the National Science Foundation of China(Grant No.51108118)
文摘The overall purpose of this research is to examine the impact of untreated sedimentation tank sludge water( USTSW) recycle on water quality during treatment of low turbidity water in coagulation—sedimentation processes. 950 m L of raw water and different concentrations of 50 m L USTSW are injected into six 1 000 m L beakers without coagulant.The results indicate that USTSW characterized as accumulated suspended solids and organic matter has active ingredients,which possess the equivalent function of coagulant. The optimal blended water turbidity is in the range of 10-20 NTU,within which USTSW recycle achieves the highest save coagulant rate. The mechanism of strengthening coagulation effect when USTSW recycle mainly depends on the chemical effect and physical effect. What is more,through scanning electron microscopy( SEM),it is found that the floc structures with USTSW recycle are more compact than those without USTSW recycle. Besides,the water quality parameters of color,NH3-N,CODMn,UV254,total aluminum,total manganese when USTSW recycle is better than the raw water without recycle,indicating that USTSW recycle can improve water quality with strengthening coagulation effect.
