采用新型复合药剂开展河道底泥原位修复技术研究,通过考察河道水质改善效果、底泥中磷含量及形态的变化确定药剂的最佳投加量.结果表明,投加复合药剂对上覆水体中TN、NH4+-N和TP均有不同程度的净化效果,且净化效果随药剂量的增加而增强,最高去除率分别达到23.52%、21.79%和81.5%,上覆水体COD去除率随药剂投加量增多呈先升后降的趋势,最高(投加量为600 mg·L-1)达到57.6%.从底泥磷含量及形态变化来看,投加药剂增大了底泥TP含量并促进底泥不稳态磷向稳定态磷转化.因此,从经济成本和修复效果方面综合分析,以投加量为600 mg·L-1对底泥污染原位修复较为合适.
A new composite agent was used for in-situ sediment remediation.The effects of remediation,the concentration of TP in the sediment,and the forms of phosphorus were investigated in this study.The results showed that the new composite agent removed TN,NH4+-N,and TP well,and an enhanced effect was achieved with a dose increase of the new composite agent.The highest removal rates of TN,NH4+-N,and TP were 23.52%,21.79%,and 81.5%,respectively.In the waterbody overlying the sediment,the removal rate of COD first increased and then decreased,as the dosage of the reagent increased,with the highest removal rate (dosage of 600 mg· L-1) reaching 57.6%.Adding the new composite agent can increase the concentration of TP in the sediment and can promote the conversion of unstable phosphorus to a steady state.Based on economic costs and remediation effects,the optimum dosage of the new composite agent was 600 mg · L-1.