低强度超声波与酸、碱协同对污泥溶胞的影响

在能量密度为0.05W·mL-1和pH范围3.0～12.0条件下,研究了超声波辐射与酸、碱协同对污泥溶胞效果的影响.结果表明,溶解性化学需氧量(SCOD)、溶解性磷(SP)和溶解性糖(SA)含量随pH增大均呈先降后升趋势.当pH为3.0时,污泥溶胞效果不高,随污泥溶液碱性增强,SCOD、SP和SA含量随pH呈指数增长,说明强碱性环境有利于污泥溶胞.超声波辐射可显著提高污泥溶胞率,而且pH越大超声波辐射改善的溶胞效率越高.pH=11.0时超声波辐射60min以内,SCOD、SP和SA含量与时间均呈线性关系,超声波/碱协同污泥溶胞为一级反应.pH大于9.0的碱性条件下,超声波辐射和提高pH均可降低VSS/TSS.依据实验数据,应用非线性优化技术得到SCOD与pH和超声波辐射时间的数学模型,其平均相对误差小于2.6%.

Effect of low intensity ultrasound/acid or alkaline combined treatment on activated sludge

The effect of ultrasonic irradiation/acid or alkaline with energy density of 0.05 W·mL-1 on activated sludge cell lysis under pH ranging from 3.0 to 12.0 has been studied experimentally in detail. The results indicated the concentrations of soluble chemical oxygen demand (SCOD), soluble phosphor (SP) and soluble polysaccharid (SA) reduced with pH first, and then increased. When pH=3.0, the efficiency of cell lysis was not high, but under basic condition the contents of SCOD, SP and SA increased exponentially with pH. Strong alkaline circumstance would benefit for cell lysis. Ultrasonic irradiation could largely improve the efficiency of cell lysis, moreover, the higher the pH, the higher the lysis efficiency enhanced by ultrasonic treatment. Under pH=11.0, when ultrasonic time was less than 60min, all of the contents of SCOD, SP and SA increased linearly with time. Sludge lysis by ultrasonic/alkaline combined treatment was first order reaction. If pH was larger than 9.0, VSS/TSS of sludge could be reduced by increasing pH and ultrasonic treatment. Based on experimental data, a mathematic model with less than 2.6% relative error, describing the relationships between SCOD and pH or irradiation time, has been obtained using no-linear optimization method.