污泥堆肥对重金属稳定化过程的影响研究

将重金属(Cd、Pb、Cu、Zn、Ni)溶液添加到污水处理厂脱水污泥中进行堆肥,考察了污泥的堆肥过程对重金属稳定化的影响。分析发现:进入污泥后各重金属中可交换态+碳酸盐结合态的总占比顺序为Cd(72.31%)>Ni(65.83%)>Zn(33.67%)>Cu(19.49%)>Pb(7.40%)。说明Pb、Cu及Zn与污泥化学物质反应较快,而Cd及Ni的反应速率相对较慢。在整个过程中Pb形态达到稳定状态最快,Cu和Ni的形态稳定速度次之,Zn形态变化稍慢,Cd变化最慢。该结论可为污泥堆肥应用于土壤重金属污染治理的研究提供参考。

STUDY ON VARIATION OF HEAVY METALS SPECIATION IN SLUDGE STABILIZATION PROCESS

Heavy metals( including Cd，Pb，Cu，Zn and Ni) solution was added into the dewatered sludge for composting．The influence of sludge composting on stabilization of these heavy metals was evaluated． The total contents and speciation ofeach heavy metal were tested during the whole conposting process． After heavy metals were added into sludge，the total metalcontent of exchangeable and carbonate bound was in sequence as Cd ( 72. 31%) ＞ Ni ( 65. 83%) ＞ Zn ( 33. 67%) ＞ Cu( 19. 49%) ＞ Pb( 7. 40%) ． The reaction of Pb，Cu，Zn with sludge went on faster，but that of Cd and Ni were relativelyslower． In the whole composting process，Pb reached the stable state first，Cu and Ni ranked the second，followed by Zn andCd． This conclusion could provide theoretical references for application of sewage compost on soil heavy metals pollution．