The occurrence, fate and removal of microplastics (MPs) in a wastewater treatment plant (WWTP) in Central Italy were investigated together with their potential adverse effects on anaerobic processes. In the influent of the WWTP, 3.6 MPs^.L^-1 were detected that mostly comprised polyester fibers and particles in the shape of films, ranging 0.1-0.5 mm and made of polyethylene and polypropylene (PP). The full-scale conventional activated sludge scheme removed 86% of MPs, with the main reduction in the primary and secondary settling. MPs particles bigger than 1 mm were not detected in the final effluent and some loss of polymers types were observed. In comparison, the pilot-scale upflow granular anaerobic sludge blanket (UASB) + anaerobic membrane bioreactor (AnMBR) configuration achieved 94% MPs removal with the abatement of 87% of fibers and 100% of particles. The results highlighted an accumulation phenomenon of MPs in the sludge and suggested the need to further investigate the effects of MPs on anaerobic processes. Accordingly, PP-MPs at concentrations from 5 PP-MPs^.gTS^-1 to 50 PP-MPs^.gTS^-1 were spiked in the pilot-scale UASB reactor that was fed with real municipal wastewater, where up to 58% decrease in methanogenic activity was observed at the exposure of 50 PP-MPs^.gTS^-1. To the best of our knowledge, the presented results will be the first to report of PP-MPs inhibition on anaerobic processes.

调查了意大利中部废水处理厂（WWTP）中微塑料（MPs）的发生，去向和清除，以及它们对厌氧工艺的潜在不利影响。在污水处理厂的影响力中，有3.6名议员^。大号^-1据检测，这些纤维主要由聚酯纤维和薄膜状颗粒组成，范围为0.1-0.5 mm，由聚乙烯和聚丙烯（PP）制成。全面的常规活性污泥方案去除了86％的MP，主要减少了一级和二级沉降。在最终流出物中未检测到大于1 mm的MPs颗粒，并且观察到一些聚合物类型的损失。相比之下，中试规模上流式颗粒厌氧污泥层（UASB）+厌氧膜生物反应器（AnMBR）配置实现了94％的MP去除，同时减少了87％的纤维和100％的颗粒。结果强调了MPs在污泥中的积累现象，并建议需要进一步研究MPs对厌氧过程的影响。因此，PP-MP的浓度为5 PP-MP^。gTS ^-1至50 PP-MP ^。gTS ^-1掺入了中试规模的UASB反应器中，该反应器中注入了真正的市政废水，在50 PP-MP暴露下，产甲烷活性降低了58％^。gTS ^-1。据我们所知，所给出的结果将是第一个报道PP-MPs对厌氧过程的抑制作用的结果。