College of Life Science and Technology, Harbin Normal University, Harbin, 150025, China.
Heilongjiang Provincial Ecological Environment Monitoring Center, Harbin, 150056, China.
J Environ Manage. 2024 Mar;354:120323. doi: 10.1016/j.jenvman.2024.120323. Epub 2024 Feb 27.
Accumulation of persistent organic pollutants polycyclic aromatic hydrocarbons (PAHs) in soil has become a global problem. Composting is considered one of the more economical methods of soil remediation and is important for the resourceful use of wastes. Agroforestry waste is produced in huge amounts and is utilized at low rates, hence there is an urgent need to manage it. Here, leaf (LVS) or rice straw (SVS) was co-composting with aged contaminated soil to investigate bacteria interaction to PAHs degradation and humus formation. The degradation rate of high molecular weight PAHs (HMW-PAHs) in LVS and SVS reached 58.9% and 52.5%, and the low molecular weight PAHs (LMW-PAHs) were 77.5% and 65%. Meanwhile, the humus increased by 44.8% and 60.5% in LVS and SVS at the end of co-composting. The topological characteristics and community assembly of the bacterial community showed that LVS had higher complexity and more keystones than SVS, suggesting that LVS might more beneficial for the degradation of PAHs. The stability of the co-occurrence network and stochastic processes (dispersal limitation) dominated community assembly made SVS beneficial for humus formation. Mantel test and structural equation models indicated that the transformation of organic matter was important for PAHs degradation and humus formation. Degradation of HMW-PAHs led to bacterial succession, which affected the formation of precursors and ultimately increased the humus content. This study provided potential technology support for improving the quality of agroforestry organic waste composting and degrading PAHs in aged contaminated soil.
土壤中持久性有机污染物多环芳烃（PAHs）的积累已成为全球性问题。堆肥被认为是一种更经济的土壤修复方法，对于废物的资源化利用非常重要。农林废弃物的产量很大，但利用率很低，因此迫切需要对其进行管理。在这里，将叶（LVS）或稻秸（SVS）与老化的污染土壤进行共堆肥，以研究细菌对 PAHs 降解和腐殖质形成的相互作用。LVS 和 SVS 中高分子量 PAHs（HMW-PAHs）的降解率分别达到 58.9%和 52.5%，低分子量 PAHs（LMW-PAHs）的降解率分别为 77.5%和 65%。同时，LVS 和 SVS 在共堆肥结束时腐殖质分别增加了 44.8%和 60.5%。细菌群落的拓扑特征和群落组装表明，LVS 的复杂性高于 SVS，关键物种也多于 SVS，这表明 LVS 可能更有利于 PAHs 的降解。共现网络的稳定性和随机过程（扩散限制）主导了群落组装，这使得 SVS 有利于腐殖质的形成。Mantel 检验和结构方程模型表明，有机质的转化对 PAHs 的降解和腐殖质的形成很重要。HMW-PAHs 的降解导致了细菌的演替，这影响了前体的形成，最终增加了腐殖质的含量。本研究为提高农林废弃物堆肥质量和降解老化污染土壤中 PAHs 提供了潜在的技术支持。
