纳米氧化锌对厌氧污泥中微生物内源代谢产物和膜污染性能的影响

Effect of ZnO nanoparticles on production and membrane fouling performance of biomass-associated products in anaerobic sludge

从厌氧污泥的角度,探究ZnO-NPs对微生物内源代谢产物(BAP)产量和膜污染性能的影响。在实验室培养的厌氧污泥中投加不同浓度的ZnO-NP,通过序批式实验和过滤实验,分别考察ZnO-NP作用下BAP的产量和膜污染性能的变化规律。发现在ZnO-NPs的短期暴露下,BAP和胞外聚合物(EPS)的总量都随着ZnO-NPs浓度的增加而增加。当ZnO-NPs浓度为300 mg·L^(-1)时,BAP和EPS的7 d总产量相较于空白对照组,增幅分别为303.4%和112%,远远高于其他实验组。过滤实验发现,随着ZnO-NPs的增加,BAP的膜污染性能不断增加。此外,通过扫描电镜(SEM)和三维荧光光谱(EEM)分别对污泥形态和BAP特性进行研究,发现在ZnO-NPs短期暴露下,ZnO-NPs的浓度越高,其对厌氧污泥的形态和BAP特性影响越大。

The purpose of this study was to research the influence of ZnO-NPs on the production of biomass-associated products（BAP） in anaerobic sludge and its membrane fouling potential. Different concentrations of ZnO-NP were added in the anaerobic sludge cultured in laboratory. The change of BAP production under ZnO-NP dosage was investigated by sequencing batch reactor, and the membrane fouling potential was evaluated through dead-end filtration expeirments.The content of BAP and extracellular polymeric substances（EPS） increased with the increasing dosage of ZnO-NPs during 7 days experiments. When the concentration of ZnO-NPs was 300 mg·L^-1, the increments of BAP and EPS were up to 303.4% and 112%, respectively, which was much higher than that of other experimental groups. Filtration experiments showed that the water flux for each experimental group decreased with the increase of ZnO-NPs concentration.Additionally, the morphology of sludge and BAP characteristics were studied by scanning electron microscopy（SEM） and three-dimensional fluorescence spectroscopy（EEM）, respectively. Greater impact on the morphology of anaerobic sludge and BAP characteristics was found under higher ZnO-NPs concentration.