投菌法对天津护仓河底泥修复的试验研究

Evaluation of microbial inoculums addition on remediation of sediment in Hucang River

针对天津市护仓河底泥污染严重、水生态系统脆弱的特点,采用投菌法作为河道底泥生物修复方法,探讨投菌法对护仓河生态修复的可行性,筛选修复效果良好的菌剂。结果表明:4种菌剂对河道底泥有机质、全氮和全磷均有不同程度的降解效果,经过52 d处理,A菌剂对上覆水和底泥体系中有机物、氮元素和磷元素总量的去除率分别为26.3%,28.3%和43.8%,B菌剂对各污染物的去除率均为45%左右,C和D菌剂效果不明显。利用因子分析法结合修复效果和修复速度综合评价,菌剂效果依次为:A菌剂>B菌剂>C菌剂>D菌剂。A菌剂能较快适应护仓河底泥环境,经过22 d处理,对底泥有机质、全氮和全磷的去除率分别为39.11%,35.52%和43.67%,而且没有对上覆水引起显著的二次污染。天津护仓河生态修复工程宜将投菌法与其他工程手段联用,从而达到水环境生态修复的目的。

Bioaugmentation was used as a biological restoration method for the remediation of sediment in Hucang River in Tianjin, according to its characteristics of heavily-polluted sediment and fragile ecosystem. The practicability of bioaugmentation on ecological remediation was studied, with evaluation of different microbial inoeulums. It was indicated that four kinds of microbial inoculums had different effects on the removal of organic matter, TN and TP in the sediment. After 52 d, 26.3% of organic matter, 28.3% of nitrogen and 43.8% of phosphorus were removed in the system including sediment and overlying water by A microbial inoeulums. Additionally, about 45% of contaminants were removed after B microbial inoeulums adding. However, C and D microbial inoculums had few effects on remediation of the systems. The comprehensive assessments of repair effects and removal rates for the microbial inoculums were performed using the factor analysis. The performances of four microbial inoculums were as follow ： A 〉 B 〉 C 〉 D. With the best performance, A microbial inoculums could adapt to the sediment environment in a short time. After A microbial inoculums addition, 39.11% of organic matter, 35.52% of TN and 43.67% of TP in the sediment were removed after 22 d, avoiding secondary pollution in the overlying water. Ecological Restoration Project in Hucang River could combine bioaugrnentation with other methods to achieve the goal of integral remediation on ecological system.