Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China.
Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China.
Water Res. 2016 May 15;95:289-99. doi: 10.1016/j.watres.2016.03.013. Epub 2016 Mar 8.
A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD loading, non of which restored SRB and SOB activities for DS-EBPR; only the final novel approach of adding 25 ± 5 mg S/L of external sulfide into the reactor at the beginning of the anoxic phase could efficiently restore the DS-EBPR system from failure. The present study represents a step towards understanding the DS-EBPR metabolism and provides an effective remedial measure for recovering a deteriorating or failed DS-EBPR system.
正在开发一种与硫转化相关的增强型生物除磷（EBPR）系统，以满足处理因海水入侵地下水和污水管以及在饮用水处理中频繁使用硫酸盐混凝剂而导致的咸水/苦咸水以及在温暖气候地区控制富营养化的需求。然而，这种新兴的生物养分去除系统中的主要功能细菌和代谢物仍知之甚少。因此，本研究旨在通过操纵实验室规模系统的恶化、故障和恢复来探索这种新的 EBPR 系统中的功能微生物和代谢。这是通过改变混合液悬浮固体（MLSS）浓度来监测和评估硫转化（包括硫酸盐还原和硫酸盐生成）、磷去除、微生物群落结构变化和化学计量参数之间的关系来实现的。结果表明，通过硫酸盐还原菌（SRB）和硫氧化菌（SOB）富集了稳定的反硝化硫转化相关 EBPR（DS-EBPR）系统。这些细菌协同参与了这个新的 EBPR 过程，从而诱导了适当水平的硫转化，这对于实现稳定的 DS-EBPR 性能至关重要，即保持硫转化强度在 15-40mgS/L，对应于最佳污泥浓度为 6.5g/L。这种硫转化范围有利于微生物群落竞争和从内部聚合物（即多硫化物或元素硫（多-S(2-)/S(0)）和聚-β-羟基烷酸酯（PHA））中获取各种能量以进行磷去除。如果超过此范围，系统可能会因糖原积累菌（GAO）的富集而恶化甚至失效。研究了四种恢复失败系统的方法：增加污泥浓度、降低盐度或使 COD 负荷加倍，这些方法都没有恢复 DS-EBPR 的 SRB 和 SOB 活性；只有在缺氧阶段开始时向反应器中添加 25±5mgS/L 的外部硫化物的最后一种新方法才能有效地从故障中恢复 DS-EBPR 系统。本研究代表了理解 DS-EBPR 代谢的一步，并为恢复恶化或失败的 DS-EBPR 系统提供了一种有效的补救措施。
