预处理温度对活性污泥发酵产氢特性的影响

为寻求适宜的种泥热处理方法,利用摇瓶发酵实验,考察了城市污水处理厂好氧活性污泥分别经65、80、95、110℃热处理30min后,其利用葡萄糖发酵产氢的特性。结果表明:在初始pH=7.0、葡萄糖浓度10g/L、接种量2gMLVSS/L条件下,35℃培养72h,经65℃和95℃处理的种泥表现出较好的发酵产氢性能,其葡萄糖的氢气转化率分别达到1.08和1.11mol/mol,污泥的比产氢率分别为8.36和9.05mmol/gMLVSS;经65℃预处理的种泥发酵体系,表现为丁酸型发酵,其葡萄糖降解率和最大产氢速率分别高达82%和11.29mL/h,而经95℃预处理的种泥发酵体系则呈现混合酸发酵特征,其葡萄糖转化率和最大产氢速率分别仅为76%和4.45mL/h。

EFFECT OF HEAT PRETREATMENT TEMPERATURES ON FERMENTATIVE HYDROGEN PRODUCTION OF ACTIVATED SLUDGE

In order to find the appropriate temperature for activated sludge heat pretreatment,aerobic activated sludge from a local sewage treatment plant were sampled and pretreated respectively under 65℃,80℃,95℃ and 110℃ for 30 min,and then their characteristics in glucose fermentation were investigated by batch cultures at 35℃.The results showed that samples after 65℃ and 95℃ heat pretreatment illustrated better effect in hydrogen production than the other pretreatment temperatures.After 72 hours fermentation with an initial glucose concentration 10g/L,the hydrogen-producing ratio from glucose and specific hydrogen yield in terms of mixed liquor volatile suspend solid(MLVSS) for sample pretreated under 95℃ reached 1.11mol/mol and 9.05mmol/gMLVSS,while 1.08mol/mol and 8.36mmol/gMLVSS for sample pretreated under 65℃,respectively.Additionally,it seemed that different pretreatment temperatures could affect the metabolic characteristics of the activated sludge.Butyric acid type fermentation and mixed acid fermentation was established for the samples after 65℃ and 95℃ heat pretreatment,respectively.A glucose degradation ratio of 82% and a maximum hydrogen-producing rate of 11.29mL/h were obtained from the sample pretreated under 65℃,while 76% and 4.45mL/h for sample pretreated under 95℃.