Developmental Research of High-Performance UASB Process by Using Interal-Circulation and Two-Stage Structure

本研究的目的是开发一种采用内循环和两级结构的高性能UASB工艺。为此，在实验室和全面的研究中，使用了各种中温条件下的废水（35 C）。结果表明：1)虽然进水废水的化学性质影响了UASB工艺的处理性能，但处理所有基质的最大COD负荷率均在25 g/L/d以上，COD去除率高达95%。2)利用光镜和电镜对厌氧生物颗粒处理多种废水的微观结构进行了研究。结果表明，UASB颗粒的微观结构与底物的降解动力学密切相关。在颗粒中发现了两种关键的结构元素，即醋酸裂解型甲烷菌和合养型微菌落。这似乎表明它们可能在污泥造粒中起重要作用。3)以谷氨酸废水为底物，对厌氧混合式反应器的处理性能进行了对比研究。厌氧混合反应器工艺的最大COD负荷率为12.0 g/L/d，是厌氧过滤工艺的1.5倍。4)采用两相厌氧消化工艺，可在产酸期有效去除废水中的硫酸盐。其中，当COD/S比为13时，硫酸盐去除率可达46%；当COD/S比为50时，HRT时间大于6小时，硫酸盐去除率可达98%。

The objective of this study is to develop a high-performance UASB process by using interal-circulation and two-stage structure. For this perpose, both the laboratory-and full-scale investigation were conducted using various wastewaters at mesophilic condition (35ﾟC). Based on the results, the following conclusions can be made :1)Although the treatment porformance of the UASB process was affected by the chemical nature of the influent wastewater, The maximum COD loading rate for treating all substrate was over 25 g/L/day for meantaining a high COD removal of 95%.2)The microstructure of anaerobic biogranules treating a wide wariety of wastwaters was investigated using light and electron micrsocopies. Results indicated that the microstructure of the UASB granules was strongly dependent on the degradation kinetics of substrates. Both the acetoclastic Methanothrix and syntrophic microcolony were found as the two key structural elements in the granules. This seems to suggest that they likely play an important role in sludge granulation.3)A comparative study on the treatment performance of anaerobic hybred reactorwas conducted by using glutamate wastewater as a substrate. The maximum capacity of COD loading rate of the anaerobic hybrid reactor process was 12.0 g/L/day which is 1.5 times of that of the anaerobic filter process.4)With two-phase anaerobic digestion process, sulfate in wastewater could be effectively removaed in acidogenic phase. In paiticular, sulfate removal efficiency reached to 46% at COD/S ratio of 13 and to 98% at COD/S ratio of 50 when HRT was loger than 6 hours.