【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。更多还原

【Abstract】 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 6.5 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.更多还原