The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of ...The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10-6 to 650×10-6 with an average of 310×10-6. In primary ores, Cd concentrations range from 14×10-6 to 2800×10-6 with an average of 767×10-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10-6 to 8200×10-6 , averaging 1661×10-6. It is shown that the oxidized ores are the main carrier and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn>Pb>Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.展开更多
HACCP体系是一个食品预防控制体系,能最大限度地降低安全风险,在世界上已得到广泛应用和认可。本文将HACCP体系运用到凡纳滨对虾工厂化循环水养殖中,以期通过HACCP体系的管理,提高养殖的成功率、安全性和效率。一、HACCP体系原理HACCP...HACCP体系是一个食品预防控制体系,能最大限度地降低安全风险,在世界上已得到广泛应用和认可。本文将HACCP体系运用到凡纳滨对虾工厂化循环水养殖中,以期通过HACCP体系的管理,提高养殖的成功率、安全性和效率。一、HACCP体系原理HACCP是英文名称Hazard Analysis and Critical Control Point的简写。展开更多
基金the National Natural Science Foundation of China（Grand No.40773072）；the “Western Talent Plan” sponsored by the Chinese Academy of Sciences（2006）；the Special Fund provided by the Chongqing Institute of Geology and Mineral Resources.
文摘The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10-6 to 650×10-6 with an average of 310×10-6. In primary ores, Cd concentrations range from 14×10-6 to 2800×10-6 with an average of 767×10-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10-6 to 8200×10-6 , averaging 1661×10-6. It is shown that the oxidized ores are the main carrier and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn>Pb>Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.
文摘HACCP体系是一个食品预防控制体系,能最大限度地降低安全风险,在世界上已得到广泛应用和认可。本文将HACCP体系运用到凡纳滨对虾工厂化循环水养殖中,以期通过HACCP体系的管理,提高养殖的成功率、安全性和效率。一、HACCP体系原理HACCP是英文名称Hazard Analysis and Critical Control Point的简写。
