堆肥化是重金属污染河湖沉积物规模化修复的重要方法之一，已有的依托腐殖质钝化修复研究受重金属种类的局限，修复能力有限。本研究创新性提出通过补充水分强化堆体渗滤液产生，从而去除部分易迁移重金属，同时利用钝化和去除两种策略实现重金属污染沉积物的有效修复，基于这一思路的研究国内外尚未见报道。本项目拟在堆肥化过程中间歇加入低浓度生物表面活性剂溶液来强化堆体中液相介质的迁移，研究水分添加方式对堆体微生物活性及群落结构影响，探究堆体持续运行下耐受的最大液体交换量；研究秸秆吸附作用对重金属动态分配的影响，探索重金属随液相介质同步迁移的规律；深入研究沉积物重金属原有平衡分配在外源有机质演替推动下的动态再平衡机制；建立基于液相基质强化迁移的堆肥化重金属污染沉积物修复方法。该修复方法突破了已有堆肥化修复策略，有望为河湖沉积物重金属污染堆肥化修复技术的发展提供更多理论依据和实践借鉴。

Composting is one of the most important methods for remediation of heavy metal pollution of river and lake sediments. However, the remediation strategy of passivation by humus cannot deal with all kinds of heavy metal pollutions. The performance of composting on the remediation still needs to be further improved. This research creatively brought forward the idea that the transportable heavy metals can be removed by the leachate enhanced by replenishing water into composting reactor. It is hopeful that both passivation and removal strategies can be used to remediate heavy metal contaminated sediments simultaneously. However, the relevant researches based on this ideas have not been reported. This project intends to strengthen the liquid medium migration in the composting process by intermittently adding low concentration biosurfactant solution. The dosage, composition, and frequency of the addition of extra solution will be examined. Effects of water addition on microbial activity and community structure in the reactor will be examined. The maximum tolerable liquid exchange capacity will be studied for the continuous operation of reactor. The effect of adsorption by straw on the dynamic distribution of heavy metals will be studied, and the law of simultaneous migration of heavy metals with liquid medium also will be explored. The dynamic redistribution mechanism of the original equilibrium distribution of heavy metals in sediment driven by the succession of exogenous organic matter will be in-depth explored. A remediation method by composting of straw and heavy metal contaminated sediment with the enhanced migration of liquid medium would be established. This remediation method breaks through the existing composting remediation strategy and is environmentally friendly. These will provide more theoretical basis and practical references for the development of environmental friendly remediation technology of heavy metal pollution in river and lake sediments.