盐度对SBR处理垃圾渗滤液污泥胞外聚合物及污泥特性的影响

EFFECT OF SALINITY ON THE EXTRACELLULAR POLYMERIC SUBSTANCES AND THE CHARACTERISTICS OF ACTIVATED SLUDGE IN SYSTEM OF LANDFILL LEACHATE TREATED BY SBR

采用序批式生物反应器(SBR)处理垃圾渗滤液,以投加Na Cl固体的方式改变体系盐度,考察盐度变化对SBR运行过程中污泥胞外聚合物(EPS)及污泥特性的影响。结果表明:盐度的增加(5~15 g/L)对SBR去除COD效果的影响不显著,而对氨氮的去除率则从92%下降至50%;污泥松散型胞外聚合物(LB-EPS)的含量从13.26 mg/g增加至31.75 mg/g,紧密型胞外聚合物(TB-EPS)从19.12 mg/g增至25.75 mg/g。对LB-EPS、TB-EPS中蛋白质(PN)与多糖(PS)进行分析可知,两类EPS中的PN与PS含量均随盐度的增加而增加,但PS的增加量大于PN。进一步将EPS含量的变化与污泥的相关特性进行分析发现,污泥体积指数(SVI)总体上随着EPS含量的增加而增加,污泥的疏水性呈现下降趋势。此外,还发现污泥的Zeta电位受到EPS与盐度的共同影响,呈现先负向减小后增大的趋势,污泥絮体结构随着盐度的增加更为松散。

The effects of salinity on the extracellular polymeric substances（ EPS） and the characteristics of activated sludge were investigated in system of landfill leachate treated by SBR. The results indicated that salinity had no significant effects on the removal rates of COD with the increase of salinity from 5 g/L to 15 g/L,while the removal rate of ammonia nitrogen decreased from 92% to 50%. Furthermore,the content of loosely bound EPS（ LB-EPS） of activated sludge increased from13. 26 mg/g to 31. 75 mg/g,and the tightly bound EPS（ TB-EPS） content increased from 19. 12 mg/g to 25. 75 mg/g. The contents of PN and PS in LB-EPS and TB-EPS increased with the increase of salinity,but the amounts of PS increased more than PN. Due to the increase of EPS contents,the sludge volume index（ SVI） increased,while the hydrophobicity of sludge decreased. In addition,the results also indicated that the structure of flocs became looser with the increase of salinity,while the Zeta potentials of the activated sludge were affected by EPS and salinity,with a trend of increasing firstly and then decreasing.