Wang Tao, Zhang Dong, Dai Lingling, Chen Yinguang, Dai Xiaohu
State key laboratory of pollution control and Resources reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Sci Rep. 2016 May 11;6:25857. doi: 10.1038/srep25857.
Extensive use of nanoparticles (NPs) in consumer and industrial products has led to concerns about their potential environmental impacts; however, the influences of different NPs (e.g., nZVI (nano zero-valent iron), Ag NPs, Fe2O3 NPs and MgO NPs) on the anaerobic digestion of sludge have not yet been studied in depth. Additionally, a new guideline or the use of different NPs in the anaerobic digestion of sludge should be established to improve the anaerobic digestion of sludge and avoid inhibitory effects. This study investigated the effects of four representative NPs (i.e., nZVI, Ag NPs, Fe2O3 NPs and MgO NPs) on methane production during the anaerobic digestion of waste activated sludge (WAS). The presence of 10 mg/g total suspended solids (TSS) nZVI and 100 mg/g TSS Fe2O3 NPs increased methane production to 120% and 117% of the control, respectively, whereas 500 mg/g TSS Ag NPs and 500 mg/g TSS MgO NPs generated lower levels of methane production (73.52% and 1.08% that of the control, respectively). These results showed that low concentrations of nZVI and Fe2O3 NPs promoted the amount of microbes (Bacteria and Archaea) and activities of key enzymes but that higher concentrations of Ag NPs and MgO NPs inhibited them.
纳米颗粒（NPs）在消费品和工业产品中的广泛使用引发了人们对其潜在环境影响的担忧；然而，不同的纳米颗粒（如纳米零价铁（nZVI）、银纳米颗粒、氧化铁纳米颗粒和氧化镁纳米颗粒）对污泥厌氧消化的影响尚未得到深入研究。此外，应该制定新的指导方针或规定在污泥厌氧消化中使用不同纳米颗粒的方法，以改善污泥的厌氧消化并避免抑制作用。本研究调查了四种代表性纳米颗粒（即nZVI、银纳米颗粒、氧化铁纳米颗粒和氧化镁纳米颗粒）对废弃活性污泥（WAS）厌氧消化过程中甲烷产生的影响。总悬浮固体（TSS）含量为10mg/g的nZVI和100mg/g TSS的氧化铁纳米颗粒的存在分别使甲烷产量提高到对照的120%和117%，而500mg/g TSS的银纳米颗粒和500mg/g TSS的氧化镁纳米颗粒产生的甲烷产量较低（分别为对照的73.52%和1.08%）。这些结果表明，低浓度的nZVI和氧化铁纳米颗粒促进了微生物（细菌和古菌）的数量和关键酶的活性，但高浓度的银纳米颗粒和氧化镁纳米颗粒则对其产生抑制作用。
