基于旋流增效的淋洗设备在重金属污染土壤中的应用

Application of Hydro-cyclone Enhanced Soil Washing Equipment in the Remediation of Heavy Metal Contaminated Soil

为解决土壤淋洗设备存在的设计依据不足、筛分组合效率低、淋洗搅拌强度不足、功能模块单一等问题,研制出一套基于旋流分级减量、旋流增效洗脱适用于不同污染类型的土壤淋洗设备。设备现场试验发现,各级筛分精度可达95%;土壤中As,Sb的去除率均达76%,相较常规淋洗设备,相同条件下,该设备淋洗效率可提高25%以上;通过氧化、气浮模块的嵌入应用,其可有效修复As-苯胺、As-苯并(a)芘、As-总石油烃(As-TPH)等复合污染土,去除率均达70%以上。该设备在上海某重金属污染场地进行中试应用发现,实际应用效果较好。

In response to the theoretic basis for the design of contaminated soil washing equipment,low screening efficiency,low stirring intensity,and few functional modules,a set of soil washing equipment based on hydro-cyclone classification and reduction,and hydro-cyclone enhanced washing and stripping,suitable for different kinds of polluted soil,has been developed.Through on-site experiments,the sieving precision of the materials remaining on the screens from each screening stage of the washing equipment reach 95%.The removal rates for As(arsenic)and Sb(antimony)can both reach 76%.Compared to the conventional washing equipment,the washing efficiency has been increased by more than 25%under the same conditions.By applying oxidation and air flotation modules,it can effectively remediate complex contaminated soils such as As-aniline,As-benzo(a)pyrene,and As-TPH(Total Petroleum Hydrocarbons)with removal rates all above 70%.The pilot application of this equipment in a heavy metal contaminated site in Shanghai has shown good practical application effects.