华北平原耕作土壤特性对基因工程菌迁移的影响

Effects of Cultivation Soil Properties on the Transport of Genetically Engineered Microorganism in Huabei Plain

基因工程菌在土壤中的迁移是影响污染土壤生物强化修复的重要因素.在华北平原饱和耕作土壤中,考察了1株阿特拉津降解基因工程菌迁移留存及其影响因素.结果表明,在饱和耕作土壤中,平流渗透是基因工程菌迁移的主要机制,其过程可用过滤模型拟合.土壤性质对孔隙水流和基因工程菌迁移具有显著影响.随着土壤粒径、孔隙率和土壤砂粒组分增加,土壤水力传导率常数增大,基因工程菌过滤系数减小,土壤对基因工程菌过滤留存作用降低.土壤条件不变时,增加入渗流量也会增大土壤水力传导率常数,减小基因工程菌过滤系数.饱和土壤中,水力传导率常数为5.02~6.70 m·d-1时,基因工程菌在土壤中的过滤系数为0.105~0.274,二者存在显著负相关关系.

The transport of genetically engineered microorganism( GEM) in the soil is considered to be the important factor influencing the enhanced bioremediation of polluted soil. The transport of an atrazine-degrading GEM and its influencing factors were investigated in the saturated cultivation soil of Huabei Plain. The results showed that horizontal infiltration was the main mechanism of GEM transport in the saturated cultivation soil. The transport process could be simulated using the filtration model. Soil properties showed significant effects on pore water flow and GEM transport in saturated soil. When particle size,porosity and sand component of the soil increased,the hydraulic conductivity constant increased and filtration coefficient of GEM decreased in saturated soil,indicating the reduced retention of GEM in the soil. An increase in infiltration flow also increased hydraulic conductivity constant in saturated soil and consequently decreased filtration coefficient of GEM. When hydraulic conductivity constants ranged from 5. 02 m·d- 1to 6. 70 m·d- 1in the saturated soil,the filtration coefficients of GEM varied from 0. 105 to 0. 274. There was a significantly negative correlation between them.