Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; SYSU-HKUST Research Centre for Innovative Environmental Technology, Sun Yat-sen University, Guangzhou, China.
Water Res. 2015 Mar 15;71:74-84. doi: 10.1016/j.watres.2014.12.051. Epub 2015 Jan 8.
The SANI(®) process (Sulfate reduction, Autotrophic denitrification and Nitrification Integrated) is a treatment system with low energy demands. The major bioreactor of this new technology is a sulfate-reducing up-flow sludge bed (SRUSB) that converts organics and provides electron donors for subsequent autotrophic denitrification. This research characterizes the granules inside the SRUSB, with the aim of improving its efficiency, maximizing its operational flexibility, and minimizing its footprint. The unique sulfate-reducing bacteria (SRB) granules serving in the SRUSB were found to increase the resilience and compactness of the SRUSB. The granules, with a compact and porous structure, showed high cohesion resisting breakage with a shear force G > 3400 s(-1). The hydrophobicity of the external surface of the mature granules remained stable at around 70% and acid volatile sulfide (AVS) accumulated at the bottom of the SRUSB. 16s rRNA gene analysis of the microbial communities revealed that Desulfobulbus (42.1%), Prosthecochloris (19%) and Trichococcus (12%) dominated the mature granular sludge. Fluorescence in situ hybridization (FISH) further showed that SRB organisms were located internally and then surrounded by non-SRB. According to the FISH results, the spatial distribution of extracellular polymeric substances (EPS) displayed protein and α-polysaccharides in the exterior and β-polysaccharide in the core of the granules. Such biological structure suggests that each SRB granule acts as an efficient and independent unit, capable of achieving both fermentation and organic conversion. The present investigation sheds light on the physicochemical and biological characteristics of the SRB granulate. This information provides valuable information for scaling-up the SANI(®) process to treat real saline sewage in Hong Kong.
SANI(®)工艺（硫酸盐还原、自养反硝化和硝化一体化）是一种低能耗的处理系统。该新技术的主要生物反应器是硫酸盐还原上流污泥床（SRUSB），它可以转化有机物并为随后的自养反硝化提供电子供体。本研究对 SRUSB 中的颗粒进行了特征描述，旨在提高其效率、最大化其操作灵活性和最小化其占地面积。研究发现，在 SRUSB 中发挥作用的独特硫酸盐还原细菌（SRB）颗粒提高了 SRUSB 的弹性和紧凑性。这些颗粒具有致密多孔的结构，具有较高的内聚强度，剪切力 G>3400s(-1)时才会发生破裂。成熟颗粒的外表面疏水性保持在 70%左右稳定，并且酸可挥发性硫化物（AVS）在 SRUSB 底部积累。微生物群落的 16s rRNA 基因分析表明，脱硫弧菌（42.1%）、原绿菌（19%）和栖热袍菌（12%）是成熟颗粒污泥的主要优势菌属。荧光原位杂交（FISH）进一步表明，SRB 生物位于内部，然后被非 SRB 包围。根据 FISH 结果，细胞外聚合物（EPS）的空间分布在外层显示蛋白质和α-多糖，在颗粒的核心显示β-多糖。这种生物结构表明，每个 SRB 颗粒都作为一个高效且独立的单元，能够同时实现发酵和有机物转化。本研究揭示了硫酸盐还原菌颗粒的物理化学和生物学特性。这些信息为在香港用 SANI(®)工艺处理实际含盐污水的放大提供了有价值的信息。
