AnMBR中溶解性微生物产物和胶体类物质特性及膜污染行为解析

The core technology of wastewater treatment plants in the future will be submerged anaerobic membrane bioreactors (AnMBR) due to concerns with respect to water quality, energy, solids generation, GHG emissions, and resource recovery. However, membrane fouling remains a major obstacle for its wider application It has been pointed out that soluble microbial products (SMP) and colloids foul AnMBR, and SMP form the majority of the effluent chemical oxygen demand (COD) from biological treatment systems. Despite the important roles of SMP and colloids, little or no attempt is made to analyse the composition of the SMP and colloids at a fundamental level, and in the main, little attempt is made to correlate the type of SMP produced with the AnMBR operation. .This technology track will attempt to understand the production of SMP and colloids in the AnMBR system, and how this affects; membrane fouling and hence energy use, effluent COD and hence wastewater recycling, and the toxicology of the effluent. Samples will be taken from AnMBRs and examined to determine the chemical composition of SMP by using sophisticated analytical instruments such as GC-MS, LC-MS, and NMR. Simultaneously, a method to separate colloids will be developed to quantify the amount of colloids and their composition. Based on the methods developed, the effects of operating parameters, especially the shock loading (organic loading rate (OLR) and hydraulic retention time (HRT)), on the stability of AnMBR performance will be investigated with a special attention on the changes of the amount and composition in SMP and colloids. Additionally, the roles of SMP and colloids with the size fractions in fouling AnMBRs, and their relative contributions will be conducted, wherein these information will be compared with the fouling occurring on the membrane to get more insights into the fouling mechanisms. It is hoped to try and derive a guide to operating the AnMBRs to minimise SMP and colloids production, alleviate fouling and hence reduce energy and capital costs.

厌氧膜生物反应器（AnMBR）被视为最具前景的厌氧污水处理技术，然而膜污染问题制约着其在污水处理中的发展应用。溶解性微生物产物（SMP）和胶体物质是造成膜污染的重要因素，且SMP是污水生物处理出水中有机物的主要成分，但以往的研究几乎未从组成成分的角度分析SMP和胶体类物质，并考察操作条件对其组分类型的影响。.本课题将探究AnMBR中SMP和胶体类物质的组成成分，分析其对出水水质的影响以及相应的膜污染机制。结合GC-MS和LC-MS等方法分析SMP中小于1kD的化学组分；选择合理的胶体类物质分离方法并定量分析其成分。调节系统运行条件，阐明其与SMP及胶体类物质组分构成的响应关系，进一步探知冲击负荷对AnMBR稳定性影响，重点分析SMP及胶体类物质的变化。解析SMP及胶体物质的组分与膜污染间的关系，探明膜污染机制，为减少系统中SMP及胶体类物质的含量，减缓膜污染以及降低系统能耗奠定基础。

厌氧膜生物反应器（AnMBR）被视为最具前景的厌氧污水处理技术之一，然而膜污染问题制约着其在污水处理中的发展应用。溶解性微生物产物（SMP）和胶体物质是污水生物处理出水中有机物的主要成分，也是造成膜污染的重要因素。然而，AnMBR的操作条件对SMP和胶体类物质的组成成分的影响却鲜有研究。本研究从负荷冲击和毒性物质投加对AnMBR性能的影响出发，在出水水质、上清液特性及微生物群落等方面进行重点研究。为了深入了解AnMBR中上清液的特性，利用不同孔径的膜过滤，将上清液分为大胶体，微胶体和溶解部分。通过各种分析和表征手段，发现大胶体和微胶体中多糖的百分比分别为36.7％和52.4％，而溶解部分中仅有10.9％，其中鼠李糖，甘露糖，葡萄糖和半乳糖是大胶体和微胶体中的主要糖类。而大胶体，微胶体和溶质中的蛋白质百分比分别为41.0％，38.6％和20.4％，其中氨基酸异亮氨酸，天冬氨酸和谷氨酸在上清液中相对富集。此外，通过对照实验发现在毒性物质（纳米钨酸铋、纳米氧化锌、氯化钠等）长期暴露下，出水的水质出现了明显的恶化，主要体现在出水COD和VFA的显著增加。进一步研究，发现毒性物质的投加还对AnMBR中上清液和污泥的特性存在很大影响。其中，SMP，胶体类物质和EPS的含量和组分都随着毒性物质暴露时间的增加而不断的变化。为了深入解析毒性物质投加对AnMBR系统中SMP和胶体类物质的组成成分的影响机理，从微生物的层面上剖析毒性物质对AnMBR系统中厌氧菌群的影响，发现了毒性物质暴露对厌氧菌群有明显的抑制作用。本课题探究了毒性物质暴露和冲击负荷作用下AnMBR中SMP和胶体类物质组分的变化，为减少系统中SMP及胶体类物质的含量，减缓膜污染以及降低系统能耗奠定基础。