School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China; College of Resources and Environment, South China Agricultural University, Guangzhou 510640, China.
College of Resources and Environment, South China Agricultural University, Guangzhou 510640, China.
Environ Pollut. 2023 Oct 15;335:122297. doi: 10.1016/j.envpol.2023.122297. Epub 2023 Aug 3.
Surfactants are widely used as a passivating agent in heavy metal passivation process, but their effect on transformation of heavy metal fraction and reduction of heavy metal resistance genes (MRGs) in composting process is still unknown. The aim of this study was to compare the effects of two anionic surfactants (rhamnolipid and sodium dodecyl sulfate) on heavy metal passivation and resistance gene reduction in chicken manure composting. The results showed that the addition of surfactant can effectively enhance degradation of organic matter (OM). Both surfactants could effectively reduce the bioavailability of heavy metals (HMs) and the relative abundance of resistance genes, especially rhamnolipids. The potential functional bacteria affecting heavy metal passivation were identified by the changes of microbial community. Redundancy analysis (RDA) showed that protease (PRT) activity was the key factor affecting the fractions of the second group of HMs including ZnF1, CuF1, CuF2, PbF1 and PbF3. These findings indicate that addition of anionic surfactants can reduce the bioavailability of HMs and the abundance of resistance genes in compost products, which is of guiding significance for the reduction of health risks in the harmless utilization of livestock and poultry manure.
表面活性剂被广泛用作重金属钝化过程中的钝化剂，但它们在堆肥过程中对重金属形态转化和重金属抗性基因（MRGs）减少的影响尚不清楚。本研究旨在比较两种阴离子表面活性剂（鼠李糖脂和十二烷基硫酸钠）对鸡粪堆肥中重金属钝化和抗性基因减少的影响。结果表明，添加表面活性剂可以有效促进有机物（OM）的降解。两种表面活性剂都能有效降低重金属（HMs）的生物可利用性和抗性基因的相对丰度，尤其是鼠李糖脂。通过微生物群落的变化来鉴定影响重金属钝化的功能细菌。冗余分析（RDA）表明，蛋白酶（PRT）活性是影响第二组包括 ZnF1、CuF1、CuF2、PbF1 和 PbF3 的 HMs 形态的关键因素。这些发现表明，添加阴离子表面活性剂可以降低堆肥产品中 HMs 的生物可利用性和抗性基因的丰度，这对减少禽畜粪便无害化利用中的健康风险具有指导意义。
