Study On The Mechanism Of Leachate After MBR By Persulfate Advanced Oxidation Technology

The current domestic leachate treatment method is commonly used MBR+ film processing, membrane treatment effluent can reach the the national emission standard of《Landfill pollution control standard(GB16889- 2008)》.But the film processing has its own shortcomings: easy to be blocked, high cleaning cost, low service life, high operation costs and high treatment costs.Since the problems of membrane treatment, many domestic scholars are dedicated to study membrane replacement technology. Advanced oxidation technology for its faster reaction rate, no secondary pollution and no selectivity, people pay much more attention on it. Our group has done research on the treatment of MBR effluent leachate activated by Fe powder, heat and ultraviolet, the effluent water quality is good after treatment by this way. Therefore through the study on the mechanism of the persulfate treatment of MBR effluent leachate, we can determine the type of free radicals as well as the dominate radical, provide theoretical support for finding the optimal process conditions, reduce processing costs. In this paper, we study on the mechanism through spectroscopy, spectrophotometry and contrast method. The main research content is: determining the type of free radicals, study on the mechanism of treatment of methyl violet by sulfate,study on the mechanism of treatment of MBR effluent leachate by two advanced oxidation processes. Some conclusions are as follows:① Two radicals are detected through spectroscopy and spectrophotometry method after persulfate activated by Fe podwer,heat and ultraviolet.② There are more free radicals in acidic condition after the activation of persulfate by Fe podwer,heat and ultraviolet. SO4-? is the dominant free radicals in acidic condition and OH? the dominant free radicals in alkaline condition;An appropriate amount of Fe powder dosage has the higher removal rate of methyl violet; The higher temperature,the higher removal rate of methyl violet;The removal rate of methyl violet reached 93.09%, 87.55%, 92.47% respectively after the reaction with persulfate activated by Fe powder, heat and ultraviolet, ultraviolet is the best activated way.③ Under the strict conditions of p H, the amount of catalyst, the dosage of oxidant and the adding way of catalyst, the H2O2 system has a higher COD removal rate, on the contrary, the Na2S2O8 system do not need so strict conditions, at any conditions,the Na2S2O8 system has a high COD removal rate. Comprehensive consideration, the Na2S2O8 system is a optimal choice in the treatment of leachate before RO film.