Experimental Study On The Treatment Of Incineration Leachate In A Two-phase Anaerobic Process Consisting Of A Continuous Stirred Tank Reactor And A Hydraulic Jet Anaerobic Bio-filter

With the continuous increase in the proportion of incineration disposal in the treatment of domestic waste,the treatment and disposal of incineration leachate has become increasingly prominent.Anaerobic biological treatment technology has become a leading technology for incineration leachate treatment because of its advantages of high efficiency,low consumption,and recyclable biological energy.Compared with the traditional single-phase anaerobic process,the two-phase anaerobic process has higher treatment efficiency and system stability when used to treat organic wastewater with high concentration and large fluctuations in water quality.It has a good application prospect in the treatment of incineration leachate.In order to investigate the treatment effects of a two-phase anaerobic process consisting of continuous stirred tank reactor(CSTR)and hydraulic jet anaerobic bio-filter(HJAF)on incineration leachate,in this subject,the actual incineration leachate was used as experimental water to study the start-up,optimization and recovery start-up of the CSTR+HJAF two-phase anaerobic process.The results showed that:After two start-up stages,which were starch solution start-up stage(39 d)and incineration leachate start-up stage(33 d),the organic loading rate of the CSTR+HJAF two-phase anaerobic process was increased to 6.243 kgCOD/(m3·d).The acidification rate and COD removal rate of CSTR were stable at 45%and 10%around respectively.The methane yield and COD removal rate of HJAF were stable at 0.27 L/gCODremoved and 98%around respectively,and the total COD removal rate of the two-phase anaerobic process was stable at 98%around.The start-up of the two-phase anaerobic process was successfully completed.The optimum reflux ratio for HJAF operation is 300%.Under the condition that the influent flow rate was 16.5 L/d(the HRTs of the CSTR and HJAF were 4 h and 3 d respectively)and the organic loading rate of the system was 4.68 kgCOD/(m3·d),the HJAF reflux ratio was adjusted to 300%,the HJAF COD removal rate was 96.3%,and the methane yield was 0.254 L/gCODremoved.The CSTR+HJAF two-phase anaerobic process still has a better treatment effect on incineration leachate under a higher organic load.Under the condition that the influent flow rate was 16.5 L/d and the HJAF reflux ratio was 300%,the influent concentration was increased to 35000 mg/L and the organic loading rate of the system was raised to 10.93 kgCOD/(m3·d)accordingly.The COD removal rate and acidification rate of the CSTR were 8.1%and 25.2%(the degree of acidification was above 46%),respectively.The COD removal rate and the methane yield of the HJAF were 92.7%and 0.206 L/g CODremoved,respectively.The effluent COD concentration of the system was 2336.2 mg/L and the total COD removal rate of the two-phase anaerobic process was 93.3%.After 2 months outage,the system was restarted with an organic loading rate of 1.04 kg/(m3 d).After 14 days of restart,the system resumed normal operation.The acidification rate of CSTR and the methane yield of HJAF were stable at 42%and 0.26 L/gCODremoved around,respectively.In addition,this subject developed HJAF anaerobic biological activated carbon inoculation transport technology.Anaerobic biofilter start-up experimental devices with different anaerobic biological activated carbon filling ratios(0%,25%,50%and 100%)were designed to study the feasibility of using anaerobic biological activated carbon inoculation to achieve rapid start-up of anaerobic biological filter.And the transportation and preservation period of anaerobic biological activated carbon was studied by analysising the variation trend of biomass and biological activity.Using anaerobic biological activated carbon inoculation can achieve rapid start-up of anaerobic biological filter.Filling anaerobic biological activated carbon(25%by volume)in the packing layer.The anaerobic bio-filter's methane yield reached 0.156 L/gCODremoved on the ninth day of start-up and showed a stable trend.On the 16th day of start-up,the COD removal rate reached a maximum and stabilized at 94.9%around.The COD removal rate and methane yield of the experimental equipment without anaerobic biological activated carbon did not increase after 14 days operating.The anaerobic biological activated carbon can be stored and transported at room temperature after being drained and sealed.During the sealed storage process,the lipid-phosphorous biomass of anaerobic biological activated carbon showed a trend of increasing first and then decreasing.After 5.75 days of storage,the biomass was 140.83 nmolP/g-filler,which was still at a relatively high level.The average values of maximum specific methanogenic production rate of anaerobic biological activated carbon were 8.541,8.143,and 7.681 mL-CH4/g-filler respectively,after 0.75 days,2.75 days and 4.75 days storage.However,on the 4.75th day,there was a lag period in the cumulative methanogenic curve.Therefore,it is recommended to keep the transport preservation time within 3 days.