Effect Of Temperature On The Treatment Of Brewery Wastewater By Separate Anaerobic Membrane Bioreactor

In this experiment,the waste water from Hans Brewery in Xi'an was treated by separate anaerobic membrane bioreactor to study the stable operation characteristics,treatment effect and gas production efficiency under different temperature and temperature shocks.Secondly,by comparing the changes of soluble microbial products(SMP),sludge particle size distribution,transmembrane pressure,membrane resistance,extracellular polymeric substances(EPS)in the sludge mixed liquor and cake layer.The effects of temperature and temperature shock on membrane fouling of anaerobic membrane bioreactor were mainly investigated.(1)In the second start-up phase,controlling the reactor temperature at 25±1?,HRT at 32 h,the influent COD concentration was lifted in the range of 1500~3500mg/L,and AnMBR was restarted only 11 d.The COD removal rate of the system was 87.06% on average.Anaerobic sludge activity,alkalinity,VFA and other indicators were stable.(2)The HRT of AnMBR was 32 h.Compared with the ambient temperature 25? reactor operation,when controlled the temperature at 35?,microbial secretion of extracellular polymer(EPS)was less,the particle size of the sludge mixture liquor and cake layer were larger,and the membrane fouling rate was slower.In addition,COD removal rate was higher,the system removal rate and the biogas performance was better,the membrane pollution rate was lower,determine the temperature under 35? for the better operating temperature.(3)The main components of EPS in the cake layer were the protein and polysaccharide at the temperature stability of 25 ? and 35 ?,and the protein concentration was much larger than the polysaccharide concentration.Proteins were the main substances that cause membrane fouling.The high excitation wavelength of tryptophan in this system was an important factor affecting the rate of membrane fouling.(4)Mesophilictemperature(35?)and ambient temperature(25?)condition after 5?temperature shock,the effluent COD concentration and the average COD removal rate did not change much.The temperature shock could increase EPS concentration of sludge mixed liquor and cake layer,reduced the sludge particle size,resulting transmembrane pressure(TMP)rapid growth,the average membrane pollution rate increased,the membrane pollution process aggravated.(5)The temperature had an important effect on the characteristics of sludge mixed liquor and the cake layer of the anaerobic membrane bioreactor.By controlling the anaerobic membrane bioreactor temperature at 35? could make the effect of reactor membrane pollution and treatment better.On the basis of this preferred temperature,keeping the temperature stable in a certain range could further delay membrane fouling.