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

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.

Key words: 厌氧序批式活性污泥法, 碱度, pH, 挥发性脂肪酸, CO₂分压