Based on investigation and laboratory test of the field soil quality in the sewage irrigation area and the Yellow River irrigation area in Baiyin city,the influences of sewage irrigation on the field soil quatity were analyzed.The results showed that those harmful substances,such as Cr,Cu,Pb,Zn,Cd,As,Hg,F etc,had exceed the content limit of the national standard and the tendency has been increasing year by year.In addition,the countermeasures for sewage irrigation control and polluted soil improvement have been preliminarily discussed.

To investigate the effects of humic acid on the speciations of heavy metals,such as Cu,Pb,Zn and Cd in sewage farm in Baiyin Prefecture,four kinds of organic matters including humic acid,EDTA,citric acid and acetic acid were added,respectively,in polluted soil with a method of successive extraction performed to determine the species of heavy metals.The results show that humic acid could remarkably decrease the content of soluble heavy metals with about 60%~80%,while increase the fractions of Fe+Al+MnO_x and carbonate,which demonstrated clearly that huimc substance,under certain conditions,could effectively increase the resistance to bioavailability and toxicity of heavy metals in sewage farm.

甘肃省环境科学设计研究院利用超临界流体萃取技术从紫苏籽中制取含有高品位α-亚麻酸的紫苏油新产品,同时还从芫荽、芹菜、花椒中制取出高级天然食用香精.该工艺与原有的水蒸气蒸馏法、压榨法、溶剂萃取法相比具有工艺简单,提取时间短,热敏物质无破坏,产品得率高,质量好,对环境友好等特点,达到国内领先水平.

提出了超临界环境技术的概念.用超临界二氧化碳直接接触法分别对样品水溶液和实际工业废水样品中的敌敌畏进行了处理与回收.样品水溶液中敌敌畏的去除率达到了100.0%.