基于硝酸盐缓释-功能微生物协同的污染底泥原位修复技术研究

In-situ Remediation of Contaminated Sediment Based on Nitrate Slow Release-Functional Microbial Compounding

重污染底泥原位修复常需外加大量电子受体,但大量实践表明电子受体直接投加存在作用时效短、微生物利用效率低等问题.针对该问题,开发了电子受体缓释-功能微生物协同的复合环境功能材料,并探讨了功能材料对底泥原位修复效果.结果表明:①复合功能材料〔以Ca(NO 3)2计,下同〕仅投加5.7 g/kg时,底泥中ORP(氧化还原电位)提升了60.17%~73.96%,AVS(酸可挥发性硫化物)去除率高达90%,是其他传统原位修复材料的1倍.②相较于单独投加Ca(NO 3)2的修复方式,复合功能材料最大可去除上覆水中33.78%的ρ(TN),而且ρ(NH4^+-N)也降低了27.90%.③复合功能材料同时促进上覆水中TP和COD Cr的去除,其去除率分别在78%和30%以上.④从经济成本和对环境影响的角度出发,在工程应用上宜用电子受体∶固定剂∶促凝剂∶发泡剂∶塑形剂∶复合微生物菌剂∶水的质量比为1∶5∶0.5∶0.5∶0.1∶1∶1的复合功能材料.研究显示,硝酸盐缓释-功能微生物复合材料是一种高效的重污染底泥原位修复材料,能显著提升底泥和上覆水中污染物去除效率,降低ρ(NH4^+-N)、ρ(COD Cr),避免上覆水体受到二次污染.

In-situ remediation of black odorous water often requires the addition of a large number of electron acceptors,but a lot of practices have proved that the direct addition of electron acceptors has short-acting effects and low microbial action efficiency,which limits the development of in-situ remediation technology for heavily polluted sediments.In response to this problem,an environmental functional material for the electron-receptor slow release-functional microbial synergy was developed,and the in-situ repair effect of functional materials on the sediment was discussed.The results show that:(1)When only 5.7 g/kg of the composite functional material(as calcium nitrate)was used,the ORP(redox potential)of the sediment increased by 60.17%-73.96%,and the AVS(acid volatile sulfide)removal rate increased up to 90%,with removal efficiency being double that of the other traditional in-situ remediation materials.(2)Compared with the remediation of adding Ca(NO 3)2 only,the composite functional material could remove 33.78%of TN and NH4^+-N concentration was reduced by 27.90%.(3)The composite functional materials also promoted the removal of TP and COD Cr in overlying water,the removal was as high as 78%and 30%,respectively.(4)From the perspective of economic cost and environmental impact,it was suggested to use compounding functional materials in engineering applications,with the mass ratio of electron acceptor∶fixative∶coagulant∶foaming agent∶plasticizer∶compound microbial agent∶water being 1∶5∶0.5∶0.5∶0.1∶1∶1.This study shows that the nitrate slow release-functional micro composite is a highly efficient in-situ remediation material for black odorous water sediments.It can significantly improve the removal efficiency of the sediments and overlying water pollutants,decrease the concentration of NH4^+-N and COD Cr,and prevent secondary pollution of the overlying water.