臭氧污泥减量过程中混合液各参数的变化

Variations of Parameters in Mixed Liquor During Sludge Reduction by Ozonation

实验用污泥的初始浓度(MLSS)分别限定为4g/L、7g/L和11g/L,用以探讨不同浓度下臭氧氧化过程中COD、N和P浓度的变化。结果表明:臭氧氧化过程中,MLSS和MLVSS基本呈线性下降;臭氧对污泥细胞的溶解可以引起混合液中COD、N和P浓度的升高,升高速率受污泥浓度和臭氧浓度影响较大;TKN和硝态氮是N的主要存在形式,TKN和TN随时间均呈先增加后趋缓的变化规律;臭氧对氨氮和亚硝酸盐氮有较强的氧化能力,二者浓度均呈先增大后减小的规律;而硝酸盐氮呈一直增加趋势;臭氧对COD的氧化也很明显,表现为COD的增加速率随氧化时间的增加而不断降低;总磷的浓度基本呈线性增加,单位质量污泥的总磷释放量差异不大;臭氧对MLSS的彻底减量会引起臭氧溶胞利用率的降低,因此应该合理控制臭氧化反应的时间。

In this experiment,three sludge samples with different initial MLSS concentration,i.e.4g/L,7g/L,11g/L, were ozonated in order to acquire the variations of COD,N,and P in the mixed liquor during the activated sludge ozonation.The results showed that the MLSS and MLVSS basically displayed a linear decreasing,and the lysis of sludge cells could increase the concentrations of COD,N and P in the mixed liquor,their increasing rates were strongly influenced by the sludge concentration and ozone gas concentration.TKN and NO_3-N were the main forms of nitrogen in the solution after ozonation.The concentrations of TKN and TN both rose first and then decreased smoothly.The ozone had strong ability to oxidize the NH_4^+-N and NO_2-N,so the NH_4^+-N and NO_2-N concentrations rose first and then droped.Nitrate had always increased during all the ozonation time.Also for ozone possessed strong oxidation ability to COD,the release rate of COD had decreased obviously during ozonation.The variation of TP concentration could be described as a liner increasing trend and the release amounts per gram of lysed sludge of TP were similar basically for different initial MLSS concentration.The completely reduction of MISS by ozone gas could drop the effective utilization of ozone gas,so the reaction time should be controlled reasonably.