铝、镁氯化物对剩余污泥产量的影响

以污泥表观产率系数Y_obs作为衡量剩余污泥产量的指标,通过向序批式活性污泥反应器(SBR)中投加氯化铝(Al Cl3)、氯化镁(MgCl_2),研究了AlCl_3、MgCl_2对胞外聚合物(EPS)、Yobs及COD去除率的影响。结果表明,当AlCl_3和MgCl_2浓度低于10 mg/L时,可以促进活性污泥微生物EPS的分泌,这是污泥表观产率系数增加的主要原因。同时发现,当AlCl_3、MgCl_2浓度分别低于最大污泥产量对应的浓度(15、10 mg/L)时,活性污泥反应器内COD平均去除率均较高;当AlCl_3、MgCl_2浓度均为5 mg/L时,COD去除率均达到最大值,分别为90. 34%和83. 64%。综上可见,控制Al Cl_3、MgCl_2浓度分别低于15、10 mg/L时,可以避开最大污泥表观产率系数区间和微生物受抑制的区间,取得较好的处理效果,达到污泥减量化目的。

Effect of Aluminium Chloride and Magnesium Chloride on Excess Sludge Yield

The sludge apparent yield coefficient Yobs was used as an index to measure the excess sludge yield.Aluminium chloride(AlCl3)and magnesium chloride(MgCl2)were added to a sequencing batch reactor(SBR),and the effects of AlCl3 and MgCl2 on extracellular polymer(EPS),sludge apparent yield coefficient Yobs and COD removal rate were explored.When the concentrations of AlCl3 and MgCl2 were less than 10 mg/L,the secretion of EPS in activated sludge could be promoted,which was the main reason for the increase of sludge apparent yield coefficient.At the same time,the average removal rate of COD by the reactor was higher when the concentrations of AlCl3 and MgCl2 were less than the concentrations corresponding to the maximum sludge yield(15 mg/L and 10 mg/L),respectively.When concentrations of AlCl3 and MgCl2 were 5 mg/L,the maximum removal rates of COD were achieved,which were 90.34%and 83.64%,respectively.Therefore,the maximum sludge apparent yield coefficient interval and microbial inhibition interval could be avoided to achieve better treatment effect and achieve the purpose of sludge reduction when the concentrations of AlCl3 and MgCl2 were controlled to be less than 15 mg/L and 10 mg/L,respectively.