The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma trea...The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma treatment technology for the environmental contaminantswas synthetically studied, and the reaction processing and mechanism between the low-pressureplasma and the environmental contaminants were theoretically analyzed. At last, the prospectsand existing problems on the application of low-pressure plasma in the field of environmentalprotection were discussed.展开更多
[Objective]The research aimed to study preparation and application of the environment-friendly compound flocculant.[Method]Chitosan（natural biological product,CTS）,ferric sulfate[Fe2（SO4） 3]and polymeric aluminum ...[Objective]The research aimed to study preparation and application of the environment-friendly compound flocculant.[Method]Chitosan（natural biological product,CTS）,ferric sulfate[Fe2（SO4） 3]and polymeric aluminum chloride（PAC） as the main raw materials,four kinds of environment-friendly flocculants were made to conduct flocculation treatment on the domestic wastewater of Wuhan Bioengineering Institute.COD and turbidity of the wastewater as the main indicators,influences of the compound flocculant formulation,flocculant dosage and pH on flocculation effect were studied.[Result]CTS/PAC and CTS/Fe2（SO4） 3 compound flocculants had better removal rates for COD and turbidity when compared with single inorganic flocculant.The best volume ratio of CTS/PAC was 1.0：5.0.The smallest dosage of CTS/PAC in each 500 ml of water sample was 4.0 ml.When pH was 7.2,removal rates of the COD and turbidity were respectively 78.5% and 98.4%,which rose by 36.5% and 21.5% respectively than that singly using PAC.[Conclusion]CTS/PAC was a kind of ideal compound flocculant and had better application prospect.展开更多
For a Chinese dairy farm with 2200 milking cows,the annual manure production and manure nutrients(nitrogen and phosphorus)were estimated.Gaseous nitrogen losses from cattle housing with scraped solid floors were based...For a Chinese dairy farm with 2200 milking cows,the annual manure production and manure nutrients(nitrogen and phosphorus)were estimated.Gaseous nitrogen losses from cattle housing with scraped solid floors were based on on-farm measurements.Based on experiences from the Netherlands,nutrient levels in the solid and liquid fractions after slurry separation were estimated.On the basis of assumptions for nutrient losses during covered lagoon storage and land application of the liquid fraction,nitrogen and phosphorous fertilization rates were calculated for the 67 hm^(2)of agricultural land that receive the liquid fraction by gravity irrigation.The results show that the application rates of nitrogen and phosphorous significantly exceed the crop needs,which will probably result in losses to soil and water.In order to aim for a balance between nutrient application and crop needs and,as such,reduce environmental harm,the authors recommend to establish application standards for nitrogen and phosphorous on arable land in China and to formulate farm-specific Nutrient Management Plans.展开更多
文摘The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma treatment technology for the environmental contaminantswas synthetically studied, and the reaction processing and mechanism between the low-pressureplasma and the environmental contaminants were theoretically analyzed. At last, the prospectsand existing problems on the application of low-pressure plasma in the field of environmentalprotection were discussed.
基金Supported by Science Plan Item of Hubei Education Department(B20084001)
文摘[Objective]The research aimed to study preparation and application of the environment-friendly compound flocculant.[Method]Chitosan（natural biological product,CTS）,ferric sulfate[Fe2（SO4） 3]and polymeric aluminum chloride（PAC） as the main raw materials,four kinds of environment-friendly flocculants were made to conduct flocculation treatment on the domestic wastewater of Wuhan Bioengineering Institute.COD and turbidity of the wastewater as the main indicators,influences of the compound flocculant formulation,flocculant dosage and pH on flocculation effect were studied.[Result]CTS/PAC and CTS/Fe2（SO4） 3 compound flocculants had better removal rates for COD and turbidity when compared with single inorganic flocculant.The best volume ratio of CTS/PAC was 1.0：5.0.The smallest dosage of CTS/PAC in each 500 ml of water sample was 4.0 ml.When pH was 7.2,removal rates of the COD and turbidity were respectively 78.5% and 98.4%,which rose by 36.5% and 21.5% respectively than that singly using PAC.[Conclusion]CTS/PAC was a kind of ideal compound flocculant and had better application prospect.
基金supported by the Ministry of Economic Affairs of the Netherlands through the TKI AF14247 Sino-Dutch Dairy Development Center(SDDDC)program(BO-27.04-001-014)the Beijing Municipal Science and Technology Plan Project(D151100005115001).
文摘For a Chinese dairy farm with 2200 milking cows,the annual manure production and manure nutrients(nitrogen and phosphorus)were estimated.Gaseous nitrogen losses from cattle housing with scraped solid floors were based on on-farm measurements.Based on experiences from the Netherlands,nutrient levels in the solid and liquid fractions after slurry separation were estimated.On the basis of assumptions for nutrient losses during covered lagoon storage and land application of the liquid fraction,nitrogen and phosphorous fertilization rates were calculated for the 67 hm^(2)of agricultural land that receive the liquid fraction by gravity irrigation.The results show that the application rates of nitrogen and phosphorous significantly exceed the crop needs,which will probably result in losses to soil and water.In order to aim for a balance between nutrient application and crop needs and,as such,reduce environmental harm,the authors recommend to establish application standards for nitrogen and phosphorous on arable land in China and to formulate farm-specific Nutrient Management Plans.
