Abstract：
This study presented the effects of hydrochar on humification, heavy metals (HMs) bioavailability and bacterial community succession during composting. Results indicated that hydrochar addition led to elevated composting temperature, 7.3% increase in humic acid (HA), and 52.9% increase in ratio of humic acid to fulvic acid. The diethylene triamine pentacetic acid extractable Zn, Cu, Pb, and Ni were reduced by 19.2%, 36.3%, 37.8%, and 27.1%, respectively, in hydrochar-involved composting system. Furthermore, main mechanisms driving the reduced HMs bioavailability by hydrochar addition were revealed. The addition of hydrochar significantly modified the microbial community structure. Correlation analysis and microbial analysis demonstrated that relative abundance of bacterial groups connected with humification and HMs passivation were increased. Consequently, the HA formation was promoted and the HMs bioavailability were reduced through bacterial bioremediation and HA complexation. This study demonstrates the addition of hydrochar as a promising strategy to mitigate the HMs bioavailability during composting.
摘要：
这项研究提出了水煤焦对腐殖质的影响，堆肥过程中重金属（HMs）的生物利用度和细菌群落演替。结果表明，水煤焦的添加导致堆肥温度升高，腐殖酸（HA）增加7.3％，腐殖酸与富里酸的比例增加了52.9%。二乙烯三胺五乙酸可萃取Zn，Cu,Pb,镍减少了19.2%，36.3%,37.8%,和27.1%，分别,在涉及水煤焦的堆肥系统中。此外，揭示了通过添加水煤焦降低HMs生物利用度的主要机制。水炭的添加显著改变了微生物群落结构。相关性分析和微生物分析表明，与腐殖质和HMs钝化相关的细菌群的相对丰度增加。因此,通过细菌生物修复和HA络合，促进了HA的形成，降低了HMs的生物利用度。这项研究表明，添加水炭是一种有希望的策略，以减轻堆肥过程中的HM生物利用度。
