养殖场鸡粪废水厌氧发酵产氢性能

在养殖场鸡粪废水中添加米糠提高废水的碳氮比,以经过不同预处理的厌氧活性污泥为接种物,控制发酵温度为36℃,初始pH为5.0,考察污泥预处理及底物质量浓度对发酵产氢的影响,并分析液相末端产物及发酵液化学需氧量(chemical oxygen demand,COD)去除率.研究结果表明,污泥的最佳预处理方法为热处理(100℃下加热15 min),发酵累积生物气产量和氢气产量分别为1 781和1 082.8 mL,是未处理组的2.52和5.85倍;鸡粪废水的适宜质量浓度为10 218 mg/L,此时氢气产量为185.1 mL/g,由Gompertz模型对产气量进行非线性拟合得拟合方程,说明该模型可很好地模拟发酵产氢过程;发酵结束后液相末端产物主要转化为乙酸和丁酸等挥发性有机酸,在不同底物质量浓度下COD去除率随底物质量浓度先增加后减小,在质量浓度为10 218 mg/L时达到26.9%.

Hydrogen Production by Anaerobic Fermentation From Wastewater in Poultry Farms

Methods of sludge pretreatment and substrate mass concentration influencing fermentation of poultry dung wastewater are investigated in this research.The anaerobic conditions are as follows: temperature is 36 ℃,pH is 5.0,and rice bran fluid is added to increase w(C)/w(N) of wastewater.Meanwhile,terminal product of liquid phase and removal rate of COD of fermentation liquor are also analyzed.Results show that the best method of sludge pretreatment is heat treatment(at 100 ℃ for 15 minutes);the production of cumulative biogas and hydrogen are 1 781 mL and 1 082.8 mL,2.52 and 5.85 times untreated group,respectively.The optimum mass concentration of poultry dung wastewater is 10 218 mg/L with hydrogen yield as 185.1 mL/g.At the end of fermentation,the products of liquid phase are organic acids such as acetic acid and butyric acid.The removal of COD varies with substrate concentration,which reaches 26.9% at the mass concentration of 10 218 mg/L.