化学浸提联合植物修复技术处理污泥重金属的效果研究

The Efficiency of Chemical Extraction Combined with Phytoremediation on Heavy Metals Removal in Sewage Sludge

研究化学浸提联合植物修复技术处理污泥重金属的效果,以自来水为对照,采用柠檬酸和EDTA为浸提剂,联合水葫芦和黄菖蒲处理含重金属污泥.试验结果表明,柠檬酸和EDTA浸提剂能够促进污泥重金属由固相向液相转移,提高浸提液中重金属浓度,且EDTA浸提效果要好于柠檬酸,水最差.各浸提剂在促进植物吸收重金属的能力上,EDTA>柠檬酸>水.EDTA、柠檬酸和水分别与植物联合使用时,植物对重金属的富集倍数可分别达到91.5倍、43.3倍和7.3倍.不同处理对污泥重金属的去除效果依次为EDTA+WH>EDTA+YF>CA+YF>CA+WH>W+YF>W+WH,其各重金属平均去除率分别为81.6%、76.1%、68.13%、62.98%、52.38%和43.74%.研究表明,化学浸提联合植物修复技术可以用于对污泥重金属的处理,且具有时间短和去除效率高的优点.

To investigate the effects of chemical extraction combined with phytoremediation on heavy metal removal of sewage sludge,citric acid （CA） and EDTA as chelating agent combined with water hy- acinth and yellow flag were used to treat sludge containing heavy metals, taking the tap water treatment as the control.The results show that CA and EDTA both promote the heavy metals transferring from the solid phase to the liquid phase in sludge,increasing the concentration of heavy metals in the leaching so- lution,and EDTA extraction effect is better than that of CA,and that of water is the worst. The abilities to promote heavy metal absorption of plant decrease from as EDTA,CA to water,and the heavy metals enrichment coefficient of plants under the EDTA, CA and water pretreatment could achieve 91.5, 43.3, and 7.3, respectively. Different treatments on the removal efficiency of heavy metals of sludge are as fol- lows ： by EDTA 4- WH 〉 EDTA 4- YF〉 CA 4- YF〉 CA 4- WH 〉 W 4- YF〉 W 4- WH, and the average re- moval rate of heavy metals were 81.6%、76. 1%.68.13%、62.98%.52.38% and 43.74%,respectively. This suggests that chemical extraction combined with phytoremediation technology can be used to treat heavy metals in sludge,wtih the advantages of short length in time and high removal efficiency.