The Technology For Treating Tea Ployphenols Wastewater

There are many reports about tea polyphenols (TP) which have much pharmaceutical properties, such as antioxidative, anticarcinogenetic, antiarteriosclerotic and inhibiting coronary heart diseases. But much less about the treatment of waste water in the process of TP production, so in this article, we paid much attention on the thesis.We first reviewed the origination, composition, pollution characteristics, and current treatment conditions of waste water in the process of TP production. Because the waste water was always high organic content, difficult to be decomposed, high content of chloroform and TP, we tried to treat the waste water with a series of processes, pretreatment (coagulation and air stripping), anaerobic acidification, and aerobic biological contact oxidation to get an acceptable process for the treatment of this kind of waste water at industrial level.In the experiments of pretreatment, we compared several coagulating agents and the best one was selected. At the same time, the coagulation conditions in our lab were optimized as well. Under such conditions, the COD value of the waste water decreased about 36%, TP content decreased about 89%, so as to make the following process easy to proceed. The chloroform content decreased to less than 13mg/L, through air aeration, and stripping curve of chloroform was given as well.In anaerobic experiment, inoculation and acclimation process proceeded at the first stage to improve the chloroform resistance of anaerobic sludge (from less than 0.5mg/L to more than 13mg/L), the COD_Cr value decreased at least 80%. Then we concluded the decomposition curves of chloroform and COD_Cr, and on the basis of this the dynamics parameters of COD_Cr were conformed under stable conditions.Through further treatment of aerobic biological contact oxidation, the COD_Cr...