Simulation and assessment of sludge concentration and rheology in the process of waste activated sludge treatment

The process of using flat-sheet membrane for simultaneous sludge thickening and digestion (MSTD) was employed. The variations of sludge concentration and rheology were characterized and simulated. Based on mass balance analysis, mathematical models were developed and successfully used to predict and evaluate the variations of sludge concentration and the digestion e ciency in the MSTD process. The apparent viscosity of sludge could be modeled as functions of mixed liquor suspended solids and shear rates. The sludge in the MSTD process showed both shear-thinning and viscoplastic behaviour, and under various shear rates di erent rheological models could be chosen to predict their flow behaviour. It was also found that sludge concentration and viscosity had significant correlations with membrane fouling in the MSTD process.     

两种城市污泥掺混水煤浆的成浆性

研究了两种高含水率城市污泥与煤粉混合研制水煤浆的可行性,以及各种影响因素包括污泥掺混比例、分散剂用量、温度及剪切时间等对成浆性能的影响.结果表明,两种污泥在南京大学研制的亚甲基萘磺钠-苯乙烯磺酸钠-马来酸钠(NDF)分散剂配合下,掺混比例控制在10%以内,可以与煤粉顺利成浆.两种污泥掺混比例分别为5%、10%水煤浆的表观粘度随分散剂的增加而降低,浆体温度的提升有利于改善水煤浆的流动性,添加污泥的水煤浆在稳定性上好于未掺污泥的水煤浆.试验结果可为城市污泥掺制水煤浆的资源化利用途径提供参考依据.     

聚乙烯蜡表观黏度测定方法的研究

介绍了采用美国试验与材料协会标准ASTMD 1986-91(2007)制定我国《聚乙烯蜡表观黏度测定法》的过程。考察不同取样量、不同转速对试验结果的影响以及方法的重复性。试验结果表明:方法的重复性较好;不同取样量、不同转速对试验结果有一定的影响,应严格按方法要求操作。     

Ca2+和PAM 对污泥流变性和脱水性能的影响

研究了Ca2+和聚丙烯酰胺(PAM)在污泥调理过程中对污泥流变行为和脱水性能的影响,通过对粘度、毛细吸水时间(CST)、比阻(SRF)等参数的测量,发现Ca2+单独作用时对污泥脱水性能的提高不大,而不同含量的Ca2+和PAM混合后,对污泥的流变行为和脱水性能都有不同程度的影响,发现20 mg/L的PAM连同140%DS的Ca2+对污泥共同进行调理时,体系表观粘度最低,脱水性能最好,同时经济成本也较低.研究表明,还不能肯定地得出可用体系的表观粘度作为调理剂最佳投加量的控制指标.