In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a hori...In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.展开更多
An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane de...An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane desalter was used to reduce the high concentrations of sodium salts in samples. In this method, trace nitrate was eluted from the concentrator column to the analytical columns, while the matrix fl owed to waste. Neither chemical pre-treatment nor sample dilution was required. In the optimized separation conditions, the method showed good linearity( R >0.99) in the 0.05 and 50 mg/L concentration range, and satisfactory repeatability(RSD<5%, n =6). The limit of detection for nitrate was 0.02 mg/L. Results showed that the valve switching system was suitable and practical for the determination of trace nitrate in seawater.展开更多
The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using fa...The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using farmers＇ fertiliser rate of 475 kg 17：8：25/ha applied at planting ＋ 235 kg Sulphate of Ammonia/ha applied as top dressing one month after and 150 kg 17：8：25/ha applied after each harvest. Yield response obtained in plots fertilised using undiluted hydroponic effluents was 16.7% lower than that recorded in plots fertilised using farmers＇ fertiliser rate. The study showed that there-is potential for using hydroponic effluents （undiluted or diluted in the ratio of 3 HE： 1 water） in fodder production as it can provide sustainable yield in the range of 39.5-41.7 t/ha per harvest. Moreover, dilution rate of hydroponic effluents has a direct impact on crop development and fresh biomass yield. Fodder crop yield responded negatively to the increase dilution of hydroponic effluents from 4HE： 0 water to 3HE： 1 water, 1HE： 1 water and 1HE： 3 water. Consequently, the use of hydroponic effluents can eventually help to save on mineral fertiliser use and reduce cost of production while at the same time address environmental hazards related to hydroponic effluents disposal.展开更多
With increasing demand for irrigation water, agricultural scientists and planners pay more attention to the utilization of diluted seawater as an alternative source for irrigation of crops. A greenhouse pot experiment...With increasing demand for irrigation water, agricultural scientists and planners pay more attention to the utilization of diluted seawater as an alternative source for irrigation of crops. A greenhouse pot experiment was conducted to study how seawater stress(SS) affects growth, water content, cationic accumulation, and active ingredients in leaves of Aloe vera after 30 d of growth in nutrient media with 0%(control), 22%(22% SS), and 42%(42% SS) seawater stress. Results indicated the SS did not change dry biomass of leaves and stems, but gradually decreased biomass allocation to roots with increasing seawater stress. Na+and Cl-in A. vera plant did not increase obviously with a big increase in seawater percentage due to low transpiration of Aloe vera. 42% SS decreased N concentration in most plant organs, but did not change or increased P concentration. Seawater stress tended to decrease concentrations of K+and Ca2+in A. vera. However, seawater salinity tended to increase the concentrations of aloin concentration in top(young) and middle leaves, and there was no significant effect of both stresses on aloin concentration in base(old) leaves. The 42% SS treatment decreased polysaccharide concentrations only in the base leaves, but not in top and middle leaves. In summary, supplying suitably diluted seawater for 30 d could increase the qualities and value of A. vera, without substantial effects on shoot dry biomass production.展开更多
基金Projects 2007CB209400 supported by the National Basic Research Program of China, 5057409050634050 by the National Natural Science Foundation of China
文摘In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.
基金Supported by the National Special Fund for Major Research Instrumentation Development(No.2012YQ090229)the Instrument Functional Exploitation and Technical Innovation Fund,Chinese Academy of Sciences(No.yg2010072)the Shandong Provincial Technology Development Plan Fund(Nos.2011SJGZ06,2012SJGZ12,2012424012)
文摘An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane desalter was used to reduce the high concentrations of sodium salts in samples. In this method, trace nitrate was eluted from the concentrator column to the analytical columns, while the matrix fl owed to waste. Neither chemical pre-treatment nor sample dilution was required. In the optimized separation conditions, the method showed good linearity( R >0.99) in the 0.05 and 50 mg/L concentration range, and satisfactory repeatability(RSD<5%, n =6). The limit of detection for nitrate was 0.02 mg/L. Results showed that the valve switching system was suitable and practical for the determination of trace nitrate in seawater.
文摘The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using farmers＇ fertiliser rate of 475 kg 17：8：25/ha applied at planting ＋ 235 kg Sulphate of Ammonia/ha applied as top dressing one month after and 150 kg 17：8：25/ha applied after each harvest. Yield response obtained in plots fertilised using undiluted hydroponic effluents was 16.7% lower than that recorded in plots fertilised using farmers＇ fertiliser rate. The study showed that there-is potential for using hydroponic effluents （undiluted or diluted in the ratio of 3 HE： 1 water） in fodder production as it can provide sustainable yield in the range of 39.5-41.7 t/ha per harvest. Moreover, dilution rate of hydroponic effluents has a direct impact on crop development and fresh biomass yield. Fodder crop yield responded negatively to the increase dilution of hydroponic effluents from 4HE： 0 water to 3HE： 1 water, 1HE： 1 water and 1HE： 3 water. Consequently, the use of hydroponic effluents can eventually help to save on mineral fertiliser use and reduce cost of production while at the same time address environmental hazards related to hydroponic effluents disposal.
基金Supported by Jiangsu Provincial Independent Innovation Program of Agricultural Science and Technology,China(No.CX(12)100504)Zhejiang Provincial Oceanic and Fishery Projects,China(No.[2013]108)the Major Scientific Research Projects of Zhejiang Province,China(No.2012C12017-3)
文摘With increasing demand for irrigation water, agricultural scientists and planners pay more attention to the utilization of diluted seawater as an alternative source for irrigation of crops. A greenhouse pot experiment was conducted to study how seawater stress(SS) affects growth, water content, cationic accumulation, and active ingredients in leaves of Aloe vera after 30 d of growth in nutrient media with 0%(control), 22%(22% SS), and 42%(42% SS) seawater stress. Results indicated the SS did not change dry biomass of leaves and stems, but gradually decreased biomass allocation to roots with increasing seawater stress. Na+and Cl-in A. vera plant did not increase obviously with a big increase in seawater percentage due to low transpiration of Aloe vera. 42% SS decreased N concentration in most plant organs, but did not change or increased P concentration. Seawater stress tended to decrease concentrations of K+and Ca2+in A. vera. However, seawater salinity tended to increase the concentrations of aloin concentration in top(young) and middle leaves, and there was no significant effect of both stresses on aloin concentration in base(old) leaves. The 42% SS treatment decreased polysaccharide concentrations only in the base leaves, but not in top and middle leaves. In summary, supplying suitably diluted seawater for 30 d could increase the qualities and value of A. vera, without substantial effects on shoot dry biomass production.
