Anaerobic Co-digestion Of Kitchen Garbage And Dairy Products Waste With Sludge

With the development of economy,the sludge problem increasingly prominent in our country.Low organic matter content of the sludge,resulting in low efficiency of anaerobic digestion technology,and difficult to large area promotion.Large output,high organic content,high potential,low utilization rate are characteristic of kitchen garbage,dairy products waste and other organic waste.Therefore,considering carries out the kitchen garbage,dairy products wastes and sludge anaerobic co-digestion,to exporle the indexes changes,the best ratio,gas composition,etc.At the same time,the dissolving organic matter,the strtcture of the microbial and diversity were analyzed,ant attempts to population characteristics analysis of anaerobic co-digestion related mechanism.The best ratio of cooked vegetable and sludge is 1:1,which biogas,biogass yeild,and methane yield are 1510.9m L,3533.4 m L/gVS,537.5 m L CH₄/gVS,average methane and methane production are 15.2%,229.8m L,which lower than kitchen garbage and sludge anaerobic co-digestion.The stabilitiy of this system is better than others,and CST is 44.5s.There are mainly organic matter of aromatic protein and soluble microbial product quantitiy.The best ratio of rice and sludge is 1:0.5,which biogas,biogass yield,and methane yield are 1956.7mL,498.2m L/gVS,82.4 m L CH₄/gVS.Average methane content,methane production were 16.5% and 325.2 mL,and methanogenesis ability is inferior to the cooked vegetable with sludge.Hydrogen sulphide at digestion before and after are 22.9 ppm,31.6ppm,respectively.At the end of digest,this ratio's CST is 159.2s that means the dewatering is worse than cooed vegetable and sludge.The best ratio of anaerobic co-digestion of kitchen garbage and sludge is 1:0.5,which the ability of biogass,methane production,average methane content and the methane yield were 2300.1 mL/gVS,603.5 mL CH₄ / gVS,30.2%,and 582.5 mL,respectively.The hydrogen sulfide concentration ratio to digest at the initial and late stages of this ratio are 37462.6 ppm,222.5 ppm,respectively,basicly can maintain in a safer level.At the process of digestion,VFA,alkalinity,ammonia nitrogen,etc are in the normal range,and the system stability is good.At the end of digestion,the CST value is 56.2 s which reflects that dewatering of sludge deterioration compared with pure sludge digestion.1:0.5 is the best ratio of dairy waste and sludge anaerobic co-digestion,which cumulative gas,biogass yield,accumulated methane,methane yield and average methane are 1854.7mL,698.3m L,250.7mL,61.5mL CH₄/gVS and 13.5%,respectively.The methane production efficiency of this system is relatively low.Before and after digestion,the hydrogen sulfide content were 22.5 ppm,1136 ppm,hydrogen sulfide content increased,the system stability is well.At the end of the digestion,CST value of 50.7 s,along with the more dairy products for the amount of waste,dehydration performance is poorer,content of soluble microbial metabolites increasing gradully.By 16 s rDNA sequencing technology after digestion of the microbial community was analyzed,and found that after joining of kitchen garbage system microbial abundance is much better than others.Pure sludge,pure of kitchen garbage group give priority to with Brevibacterium,metabolic type for carbon dioxide.The rest of the group of methanogens mainly Methanobacterium,Methanosarcina,Brevibacterium?acetic acid metabolism and metabolism of carbon dioxide?.