氧化锌纳米颗粒对污泥厌氧消化过程的影响研究

摘要

The impact of Zinc oxide nanoparticles (ZnO-NPs) (0,2,30,60,90,120 and 150mg/g-VSS) on the anaerobic digestion of excess activated sludge was investigated and the possible dose-effect relationship was achieved.Results indicated that less adverse effects of ZnO-NPs were found on anaerobic digestion of excess activated sludge at the low exposure concentration (2mg/g-VSS).However,significant effects were observed on the anaerobic digestion including biogas production,degradation efficiency of organics as well as reduction rate of sludge,but no significant effects was found on the volatile fatty acids (VFAs).The average daily gas production plummeted when the exposure concentration of ZnO-NPs was increased from 30mg/g-VSS to 120mg/g-VSS,but no obvious decrease of daily gas production was observed as the concentration was increased from 120mg/g-VSS to 150mg/g-VSS.In additon,ZnO-NPs could significantly inhibit the degradation efficiency of organic matter and the sludge reduction rate,and with the increasing of ZnO-NPs concentration from 30mg/g-VSS to 120mg/g-VSS,soluble chemical oxygen demand (SCOD) removal rate,total chemical oxygen demand (TCOD) removal rate and R(vss/rss)value was decreased to 3％,36.5％ and 74％ of the control.Sludge reduction rate was reduced from 23％ to 4.8％ of the control when the ZnO-NPs concentration increased from 2mg/g-VSS to 150mg/g-VSS.The results help evaluating the inhibitory effects of nanoparticles on anaerobic digestion process.%建立了污泥厌氧消化反应器,以氧化锌纳米颗粒(ZnO-NPs)为研究对象,研究了不同浓度ZnO-NPs(0,2,30,60,90,120,150mg/g-VSS)对污泥厌氧消化过程的影响,分析了可能存在的剂量-效应关系.低浓度(2mg/g-VSS)ZnO-NPs对污泥厌氧消化过程影响较小;较高浓度下,ZnO-NPs对污泥厌氧消化产气效率、有机物降解效率和污泥减量效果等具有显著影响,而对挥发酸产量及其组成无显著影响.ZnO-NPs暴露浓度为30,60,90,120mg/g-VSS时,平均日产气量直线下降,在120mg/g-VSS浓度后平均日产气量为对照组的10％左右.ZnO-NPs对有机物降解效和污泥减量存在明显抑制作用,且随着ZnO-NPs浓度的升高,SCOD去除率、TCOD去除率和R(VSS/Tss)值降低.ZnO-NPs浓度升高到120mg/g-VSS时,SCOD去除率、TCOD去除率和R(VSS/TSS)值分别减少到对照组的3％、36.5％和74％.此外,当ZnO-NPs暴露浓度从2mg/g-VSS升高到150mg/g-VSS时,污泥减量率从23％左右下降至4.8％左右.