Study On The Effects Of Releasing Proteins From Excess Sludge By Physical-biological Enzyme Complex Process

Currently,processing method for extracting protein from the remaining sludge can be divided into biological,mechanical,physical,chemical,and its co-processing.The enzymatic treatment with sludge technology is a new science and technology,which can not only destroy the cell wall of sludge,respect to the base,heat treatment,but has the advantage with the low energy consumption,mild reaction conditions,byproducts content and so on.This paper mainly focuses on extracting protein from the remaining sludge and other issues by use of protease protein.First,the remaining sludge is broken by three pretreatment technology,which are the ultrasonic,thermal hydrolysis,mechanical to investigate the rule of the release of protein from sludge,preliminary screening the best sludge crushing method.Then,under the residual sludge without any pre-treatment of the premise,the effect of biological enzyme treatment on the extraction rate of protein was studied.The article mainly aims at explaining optimizing the process of enzyme hydrolysis of excess sludge releasing proteins.The effects of enzyme types,solid-liquid ratio,pH,reaction time,enzyme concentration and other factors on sludge release proteins were investigated and discussed.Through comparing on the effect of releasing protein from sludge by four kinds of enzyme,the experimental results showed that the efficiency of sludge hydrolysis could be greatly improved by alkaline.Therefore,alkaline protease was selected as the biological enzyme for the hydrolysis of excess sludge..Alkaline by using hydrolysis sludge protein is an efficient,low consumption,energy saving methods.Then,the reaction of ultrasonic collaborative sodium citrate with alkaline hydrolysis of excess sludge,protein concentration which was obtained is superior to sonication or sodium citrate separately pretreatment.While ultrasound synergistic SC and enzymatic hydrolyzed sludge and achieved good results,it will be regulated to the different power and time to break different residual sludge,and during the reaction,there are high energy consumption and heat large,so in the practical application depending on the required amount of sludge,different requirements for the degree of sludge cracked and how to regulate the operation of ultrasonic conditions and other factors have yet to be further studied.