Effects Of Microwave Hydrolysis On Carbon Release And Fertilizer Efficiency In Concentrated Sludge

A microwave hydrolysis process was used to dissolve the concentrated sludge and release SCOD and VFAs as a carbon source for sewage treatment.In the process of fully obtaining high quality carbon source,a proper amount of phosphorus locking nitrogen fixing agent is added to control the release of nitrogen and phosphorus,and the fertilizer efficiency of the sludge is maintained.Effects of water content of sludge,microwave heating rate,microwave power and p H on the release of SCOD sludge,preferably the phosphorus locking agent,fixing agent,to determine both the optimal ratio,dosage and dosing sequence,studied the effect of phosphorus nitrogen fixing agent on the lock release of carbon source,discusses the optimum temperature of acid hydrolysis and the best inoculation ratio.The results and conclusions of this study are as follows:(1)By microwave digestion technology of cell sludge concentration,sludge water content 97%,microwave heating rate of 8.2 ? /min,microwave power 160 W,p H9.0 is the best experimental conditions.The conditions of SCOD in the supernatant of 1043.84mg/L,ammonia nitrogen and total phosphorus 82.96mg/L,51.46mg/L;growth rate of SCOD 887.84mg/L,ammonia nitrogen 43.32mg/L,total phosphorus 28.73mg/L;growth rates were 569.13%,109.28% 126.40%.(2)PAC was selected as phosphorus locking agent,and bentonite was selected as nitrogen fixing agent;phosphorus locking agent 1.4 g/L,nitrogen fixing agent 9 g/L is the optimal ratio,the first cast reinforced nitrogen agent adding phosphorus locking agent,the amount of dissolved total phosphorus in the supernatant was 13.48 mg/L,ammonia nitrogen is 36.07 mg/L,lock phosphorus was 73.80%,the rate of nitrogen fixation was 56.52%.SCOD dropped from 1059.61mg/L to 560.1mg/L.(3)The hydrolysis acidification temperature was 45? and the inoculation ratio was 30%,and the concentration of VFAs was the highest.After reaction of 12 h can obtain higher VFAs and SCOD,their contents were 1620mg/L and 1940mg/L,the growth rates were 211.1%,198.46%;because in the process of hydrolysis and acidification by adding a lock of phosphorus and nitrogen fixation agent,ammonia nitrogen and phosphate content is increased but the growth rate is low,24.85% and 21.6% respectively.(4)Compared with the experimental study of the microwave hydrolysis of the early stage of untreated nitrogen fixing agents,the VFAs of the supernatant increased by 69.1%,SCOD increased by 30.46%,ammonia nitrogen decreased by 198.15%,and orthophosphate reduced by 74.4%.At this time,C/N was 39.61,and C/P was 115.52,which increased by 41.83% and 27.61% respectively.The carbon source is better,and the efficiency of the sludge is still maintained.It is proved that the addition of lock phosphorus nitrogen fixing agent to the microwave hydrolysis of carbon source can optimize the carbon source,and it is feasible to use the supernatant to supplement the influent carbon source.