Revealing the Mechanisms of Polyethylene Microplastics Affecting Anaerobic Digestion of Waste Activated Sludge
Revealing the Mechanisms of Polyethylene Microplastics Affecting Anaerobic Digestion of Waste Activated Sludge
复制标题
揭示聚乙烯微塑料影响废弃活性污泥厌氧消化的机制
DOI：
10.1021/acs.est.9b02971
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发表时间：
2019
影响因子：
11.4
通讯作者：
Ni Bing Jie
中科院分区：
文献类型：
--
作者：
Wei Wei;Huang Qi Su;Sun Jing;Dai Xiaohu;Ni Bing Jie
污水污泥中残留的聚乙烯（PE）微塑料不可避免地进入厌氧消化系统。到目前为止，还没有关于PE微塑料影响废物活性污泥（WAS）厌氧消化的机制的报道。本研究采用分批和连续试验评估了机制。短时间暴露于较低水平的PE微塑料（即，10、30和60个颗粒/g-TS）没有显著影响甲烷产量，但是更高水平的PE微塑料（即，100和200个颗粒/g TS）显著（P= 0.006和0.0003）降低甲烷产生12.4- 27.5%，具有较低的甲烷势和水解系数。在超过130天的连续试验中，以200个PE微塑料颗粒/g TS进料WAS与破坏相比减少了高达27.3%（P= 2.18 × 10-18），并导致消化污泥处置体积增加了9.1%（P= 0.002）。相应地，微生物群落向反厌氧消化方向移动。一项机制研究表明，PE微塑料的负面影响可能归因于活性氧（ROS）的诱导，而不是释放的乙酰柠檬酸三正丁酯。ROS的产生导致细胞活力降低7.6-15.4%，从而抑制污泥水解、酸化和产甲烷。
Polyethylene (PE) microplastics retained in sewage sludge inevitably enter the anaerobic digestion system. To date, no information has been reported on the mechanisms of PE microplastics affecting anaerobic digestion of waste activated sludge (WAS). This study evaluated the mechanisms using batch and continuous tests. Short exposure to PE microplastics at lower levels (i.e., 10, 30, and 60 particles/g-TS) did not significantly affect the methane production, but higher levels of PE microplastics (i.e., 100 and 200 particles/g TS) significantly (P= 0.006 and 0.0003) decreased methane production by 12.4–27.5%, with a lower methane potential and hydrolysis coefficient. In continuous test over 130 days, feeding WAS with 200 particles PE microplastics/g TS decreased vs destruction by up to 27.3% (P= 2.18 × 10–18) and resulted in a 9.1% (P= 0.002) increase in the volume of digested sludge for disposal. Correspondingly, the microbial community was shifted in the direction against anaerobic digestion. A mechanisms study revealed that the negative effect of PE microplastics was likely attributed to the induction of reactive oxygen species (ROS) rather than the released acetyl tri-n-butyl citrate. The generation of ROS caused a 7.6–15.4% reduction of cell viability, thereby restraining sludge hydrolysis, acidification, and methanogenesis.