Experimental Study On Treatment Of Simulated Printing And Dyeing Wastewater By High Concentration Granular Sludge Anaerobic Reactor

Anaerobic reactor technology has become a research hotspot in the field of sewage biological treatment because of its low operating cost,good resistance to poison and impact,and diverse microbial species.In this experiment,an anaerobic reactor suitable for high-concentration anaerobic granular sludge was prepared.In view of the uneven distribution of water in the process of treating wastewater in the traditional anaerobic reactor,an improved scheme was proposed,and the water of the traditional biological filter bed was used.In the way,the water is fixed on the nozzle plate above the water plate of the perforated cloth,and a certain grade of stones is placed on the nozzle to ensure uniform water distribution of the anaerobic reactor.In addition,in order to solve the problem of large concentration of granular sludge,a support layer is arranged in the middle of the anaerobic reactor,and a filter screen is placed on the support layer to promote the interaction between the anaerobic granular sludge and the pollutant matrix.The research results show that the new high-efficiency anaerobic reactor uses"physical granular sludge"as the inoculated sludge,and the glucose is equipped with water to acclimate the granular sludge,forming mature anaerobic granular sludge in about one month.In this process,the COD removal rate is rising.High,stable and maintained above 80%,the performance of granular sludge is good.In the second stage,the domestication of simulated printing and dyeing wastewater was used to investigate the effects of influent COD concentration,physical particle sludge concentration and hydraulic retention time on the operation of anaerobic reactors,and the optimal operating parameters of high efficiency anaerobic reactor wastewater treatment were determined.In the environment of 25°C,the influent COD=5000mg/L,HRT=9h,reflux ratio=1,pH=6.7~7.7,under this operating condition,the degradation rate of COD can be kept above 80%.The volatile fatty acid VFA is below 3.0mmol/L,the effluent alkalinity is 30~40mmol/L,SS=30.56g/L,VSS=25.71g/L,VSS/SS=84.12%,and the anaerobic reactor can withstand certain impact load;when the hydraulic retention time is shortened to 6h,the granular sludge in the anaerobic reactor disintegrates,the COD removal rate drops below 70%,and the degradation rate is greatly reduced.The concentration of granular sludge is increased at the support layer,and the removal rate of COD is as high as 90%;at this time,the volume load reaches 10 kgCOD/m~3·d,and the reactor is operating normally.The new anaerobic reactor treats printing and dyeing wastewater.The anaerobic granular sludge in the reactor is rich in microbial flora,including Brevibacterium and filamentous bacteria.In the initial stage of operation,the granular sludge becomes smaller due to the impact of printing and dyeing wastewater,but the particle size of the granular sludge is increasing after it is adapted to the printing and dyeing wastewater.The sludge concentration,mechanical strength and particle size distribution in different culture stages are closely related to the effluent COD of the anaerobic reactor.When the mechanical strength of granular sludge is high and the sludge concentration is high,the effluent water quality is relatively good.Under the optimal conditions of operation,the particle size is greater than 0.8mm,accounting for about 50%.The strength is 81.46%.