Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China.
Bioresour Technol. 2018 May;256:456-465. doi: 10.1016/j.biortech.2018.02.055. Epub 2018 Feb 15.
Biochemical properties of granules are of vital importance to UASB performance. This study characterized the granules cultivated at different COD/SO ratios to elucidate the influence of sulfidogenesis on starch wastewater (1000 mg-COD L) biodegradation kinetics and process stability. Suitable sulfate addition enriched granular microecosystems and stimulated the secretion of extracellular substances, facilitating cells cohersion and sludge aggregation. The percentage of granules larger than 2.8 mm increased from <10.0% to 58.8-69.4% with decreasing COD/SO ratio from 10 to 2. Starch-fed granules tended to grow flagella-like filaments on the surface. The filaments overwhelmed by hydrophilic biopolymers had high affinity for biogas-bubbles and water-molecules aggravating granule floatation and washout. 16 s rRNA gene analysis revealed that decreasing COD/SO ratio shifted Syntrophobacterales to Desulfovibrio, which co-worked with Methanosaeta while suppressing Methanobacterium thereby altering starch bioconversion routes. Decrease in Syntrophobacterales caused propionate accumulation and slight process upset.
颗粒的生化特性对 UASB 性能至关重要。本研究对在不同 COD/SO 比下培养的颗粒进行了表征，以阐明硫化物生成对淀粉废水（1000mg-COD L）生物降解动力学和过程稳定性的影响。适量硫酸盐的添加丰富了颗粒微生态系统，并刺激了细胞间物质的分泌，促进了细胞凝聚和污泥聚集。随着 COD/SO 比从 10 降低到 2，大于 2.8mm 的颗粒百分比从<10.0%增加到 58.8-69.4%。用淀粉喂养的颗粒在表面上往往会长出鞭毛状的细丝。被亲水性生物聚合物淹没的细丝对沼气泡和水分子有很高的亲和力，从而加剧了颗粒的浮起和冲洗。16s rRNA 基因分析表明，降低 COD/SO 比会使硫杆菌科转移到脱硫弧菌科，脱硫弧菌科与产甲烷菌科一起工作，同时抑制甲烷杆菌科，从而改变淀粉的生物转化途径。硫杆菌科的减少导致丙酸的积累和轻微的工艺波动。
