Experimental Study On Treatment Of Rural Domestic Sewage By Hybrid Anaerobic Baffled Reactor (HABR)

In the vast rural areas of China,the untreated and uncontrolled discharge of domestic sewage is very common.However,the use of traditional aerobic biological treatment methods has the problems of high capital construction costs and high cost of running energy.In order to solve this problem,the experiment A five-compartment HABR reactor was proposed to treat rural domestic sewage.In order to explore the effect of the reactor in treating rural domestic sewage and achieve its purpose of efficient and stable operation,this experiment has carried out research on its start-up and operation rules.In the start-up experiment phase,the method of gradually shortening HRT was used to start the study during the start-up process.The removal rule of pollutants and the characteristics of granular sludge and the filming conditions of the fillers were observed.In the experimental stage of operation,the effects of HRT,influent COD concentration and temperature on the operating status of the reactor were investigated,and the following experimental results were obtained:The HABR reactor was started using a low load method.The initial HRT was 36 hours,and the HRT was gradually shortened.When the hydraulic retention time was reduced to 12 hours,the COD removal rate was stable at 70% or more,and the startup was successful.The startup period lasted 41 days.The removal of COD in the reactor mainly occurs in the front-end compartment,and the removal rate of COD in the back-end compartment is relatively low.No irreversible transition acidification occurred in the reactor as a whole,and the acidification reaction mainly occurred in the front end compartment.The alkalinity of each compartment rose along the flow,and the VFA decreased along the flow.The sludge showed obvious granulation,but the granularity of each compartment showed a significant decrease along the direction of flow,and the anaerobic sludge settlement performance in the reactor was good.Gas production was negatively correlated with HRT and positively correlated with system COD concentration.Within a certain temperature range,gas production was positively correlated with temperature.During the HABR operation stage,the reactor has a good removal effect on COD with the highest removal rate of 88.85%.The COD removal rate is positively correlated with temperature and influent COD concentration and negatively correlated with HRT.When the influent COD concentration is low,the COD is mainly removed in the front end compartment.When the influent COD concentration is increased,the treatment efficiency of the rear compartment of the reactor is increased and the center of gravity of the reactor is shifted.The effluent COD reaches the irrigation water quality.Standard?GB 5084-2005?.The reactor has good processing capability to the SS,and the longer HRT is more beneficial to the removal of the SS,while the change of the influent COD concentration has almost no effect on the removal of the SS.The temperature and the SS removal rate have a certain positive correlation,and the outflow SS meets the Class I B standard in the "Standard for Discharge of Pollutants from Urban Wastewater Treatment Plants"?GB18918-2002?.The removal effect of TP on the reactor is not good,and there is almost no effect of removal.Negative removal rate occurs in most cases of NH₄⁺-N and TN.NH₄⁺-N and TN concentrations in the reactor increase along the course.The reactor front-end compartment mainly produces acid fermentation,and the back-end compartment mainly produces methane reaction.The change of pH value generally showed a first decrease and then a higher trend.When the HRT is longer and the influent COD concentration is smaller,the lowest pH value appears in the first compartment.When the HRT shortens and the influent COD concentration increases,the lowest The pH value appears in the second compartment.The reactor handles the center of gravity and moves backward.The HABR reactor has a good impact load capacity.The particle size of granular sludge has a tendency to decrease along the direction of water flow.The degree of sludge granularity is superior to that of the back-end chamber in the front-end compartment,and the sludge sedimentation rate is good.The concentration of sludge in each compartment remained basically stable,and the concentration of sludge in each compartment gradually increased along the direction of water flow.The gas production of anaerobic sludge is positively correlated with the COD concentration and temperature and negatively correlated with HRT.The gas production along the reactor is larger in the third and fourth compartments,and the gas production in the first,second and fifth compartments is relatively low.