酸析黑液厌氧生物处理效果研究

Efficiency of Anaerobic Treatment of Acid-precipitated Black Liquor

关键词:  UASB反应器  黑液  胞外聚合物（EPS）  Zeta电位  硫酸盐

Key Words:UASB reactor  black liquor  extracellular polymeric substances(EPS)  Zeta potential  sulfate

摘要:采用上流式厌氧污泥床（UASB）反应器对酸析黑液进行处理，分析了酸析黑液的厌氧可生化性（BD），重点研究了不同COD容积负荷和硫酸盐容积负荷下，反应器对COD和硫酸盐的去除效果，系统pH值、氧化还原电位（ORP）和甲烷产率的变化，反应器内污泥胞外聚合物（EPS）中蛋白质和多糖含量的变化以及污泥表面Zeta电位的变化，并结合扫描电镜观察酸析黑液厌氧处理前后污泥的形态特征。结果表明，该酸析黑液的厌氧可生化性较好，BD为85.07%。反应器随着进水COD容积负荷的增加，COD去除率先上升后下降。随着进水硫酸盐容积负荷的增加，硫酸盐去除率逐渐增大。当COD_Cr容积负荷为2.00 kg/(m³·d)时，COD_Cr去除率最大值在49%;当硫酸盐容积负荷提高到12.91 kg/(m³·d)时，硫酸盐去除率上升至42%左右。系统pH值随着COD容积负荷的增加而降低，ORP随着COD容积负荷的增加而降低，最后稳定在-430 mV左右，产甲烷速率随着COD容积负荷的增加先升高后降低，最大值为0.225 L/d。进水COD容积负荷的提高使得EPS中蛋白质和多糖含量升高，污泥表面Zeta电位降低，颗粒污泥表层变得紧密厚实。

Abstract:Anaerobic treatment of acid-precipitated black liquor was studied in an up-flow anaerobic sludge bed (UASB) reactor. The anaerobic biodegradability (BD) of the black liquor was tested. Changes of the removal efficiency of chemical oxygen demand (COD) and sulfate, the pH and oxidation reduction potential (ORP), methane production rate, contents of protein and polysaccharide in extracellular polymeric substances(EPS) of sludge, Zeta potential on the surface of the sludge and surface characteristics of sludge in different COD and sulfate volume loading conditions with investigated . Results showed that the anaerobic biodegradability of the black liquor was good and the BD was 85.07%.With the increase of influent organic loading rate, removal efficiency of COD rose first and fell afterwards, but sulfate removal rate kept increasing gradually. When COD_Cr organic loading rate was 2.00 kg/(m³·d), the COD_Cr removal rate came to the maximum value of 49%. When sulfate loading rate was 12.91 kg/(m³·d), the mean sulfate removal rate rose to about 42%. In the treatment process, pH fell gradually, ORP reduced to -430 mV slowly, methane production rate increased to 0.225 L/d at first and then decreased. The increase of COD loading of the influent contributed to higher content of protein and polysaccharide in EPS, lower Zeta potential on the surface of the sludge, and the surface of granular sludge surface became clean and dense.