进水碱度对厌氧序批式活性污泥法工艺的影响  

Effect of influent alkalinity on anaerobic sequencing batch reactor

作　　者：岳秀萍[1] 付梅红[1] 李亚新[1] 曹京哲[2] 

机构地区：[1]太原理工大学环境科学与工程学院,山西太原030024 [2]太原市市政工程设计研究院,山西太原030002

出　　处：《化工学报》2008年第5期1257-1263,共7页CIESC Journal

基　　金：国家自然科学基金项目(50578102)~~

摘　　要：厌氧序批式活性污泥法(ASBR)试验装置有效容积6L,间歇运行,用葡萄糖人工合成废水为底物,进水COD0浓度6700mg.L-1,进水中逐步减少碱度(Alk)投加量。考察了COD0/Alk分别为1.0:1、2.0:1、2.5:1、3.4:1、4.2:1和4.8:1等6种碱度条件下的挥发性脂肪酸(VFA)、碳酸氢盐碱度(BAlk)、CO2分压和pH的变化规律,以确定偏酸性条件下ASBR工艺的运行效果和稳定性。结果表明,进水碱度对VFA、BAlk、CO2分压和pH均有影响,对反应初期的产酸速率的影响尤其突出。COD0/Alk=1.0:1时,消化液pH基本保持在7.20以上;COD0/Alk=3.4:1时,反应初期产酸速率增加,出现了pH<6.5的时段,消化过程已经向偏酸性发酵状态发展;COD0/Alk≥4.2:1之后,反应期内大部分时段的pH低于6.5,最低pH为6.10,偏酸性程度增大,但进行的仍是典型的以CH4为最终产物的厌氧消化过程。所有碱度条件下的COD去除率均≥97%,证明了ASBR工艺在低pH、低碱度下实现产甲烷过程的可行性。Intermittent running was carried out in a 6 L ASBR by using glucose as substrate, and with influent COD 6700 mg ·L^-1. Alkalinity added into the influent was gradually lowered down, and the ratios of COD0 to alkalinity （COD0/Alk） were respectively 1. 0 ： 1, 2.0 ： 1, 2. 5 ： 1, 3. 4 ： 1, 4. 2 ： 1 and 4. 8 ： 1. The aim of this work was to investigate the change of pH, volatile fatty acid （VFA）, bicarbonate alkalinity （BAlk） and CO2 pressure in anaerobic sequencing batch reactor （ASBR） for treating high-strength carbohydrate wastewater, and demonstrate the efficiency and stability of ASBR process at a lower pH. The results showed that alkalinity dosage had significant influences on VFA, BAlk, CO2 pressure and pH, especially acid-production rate within the first 0.5 h of reaction periods. When COD0/Alk was 1.0 ： 1, the pH values were always above 7. 20. There was a higher acid-production rate and partial pH below 6.5 at the ratio of 3.4 ： 1, which indicated that the digested liquid became acidic. It was found that the pH values were almost maintained at less than 6. g while the ratios were 4. 2 ： 1 and 4. 8 ： 1, but methanogenic process was stable. During the whole operation, the process behavior was steady with COD removal efficiency higher than 97%, which proved the feasibility of methane production with ASBR at a low pH and low alkalinity.

关 键 词：厌氧序批式活性污泥法 碱度 PH 挥发性脂肪酸 CO2分压 

分 类 号：X17[环境科学与工程—环境科学] TQ92[轻工技术与工程—发酵工程]