Effect Of Repair Factors On Anarobic Fermentation Under High Salt And Low Temperature Stresss

Anaerobic digestion is one of the most effective ways to handle kitchen waste.In the continuous anaerobic digestion process,the salt in the kitchen waste gradually accumulates to form a high-salt environment,but the salinity inhibits the anaerobic digestion system.In addition,considering that the winter in northern China lasts for five months,the long-term low temperature causes poor gas production by anaerobic fermentation.External heating is required to maintain good fermentation performance,which undoubtedly increases production costs.Therefore,this study examined the effects of repair factors on anaerobic fermentation under high salt and low temperature conditions.In order to solve the inhibition of high salt environment on anaerobic fermentation.This study investigated the alleviation of high salt inhibition by exogenous repair factors ammonium acetate and betaine.By comprehensively analyzing the data change images of various parameters,it can be found that the optimal addition amount of ammonium acetate is 1 g/L,and the effect on the anaerobic fermentation system is significant in the later stage(400 h-720 h).The analysis of high salt betaine gradient experimental data can find beets.The optimum addition amount of the base is 0.12 g/L and it can function in the early stage(0 h-400 h)to accelerate the initiation of the anaerobic digestion reaction.In order to achieve a better state of fermentation and effectively solve the problem of inhibition of anaerobic digestion in a high salt environment,an experiment of optimal mixing of ammonium acetate and betaine was carried out.The results showed that the optimal addition of ammonium acetate and betaine was better than that of the control group under high salt conditions,the cumulative yield of methane increased by about 2 times,the methane concentration increased by about 20%,and the biogas production increased by 1.5 times.The acidification rate was accelerated by 90 h,and the pH of the system was stabilized 200 h earlier.It indicated that the optimal addition of ammonium acetate and betaine could significantly alleviate the stress inhibition effect of high salt environment on anaerobic microbial flora.After the optimal combination of the two repair factors,they do not interfere with each other and promote each other,completely solving the inhibition of anaerobic digestion by high salt environment.The low temperature conditions severely inhibited the activity of various enzymes in anaerobic fermentation,while the three metal ions of Fe,Co and Ni were important components of the enzyme.It was found that the optimal addition of three metal ions can effectively promote Anaerobic fermentation.Comparing the Ni2+ gradient experiment with the optimal addition experiments of three metal ions of Fe,Co and Ni,it can be found that the gas production increased from 3720 mL to 5065 mL,the cumulative methane production increased from 1774 mL to 2795 mL,and the methane yield was from 212.64 mL/(g·VS)The increase to 335.16 mL/(g-VS)increases the total carbon utilization from 27.67%to 43.56%.It can be seen that the effects of Fe,Co and Ni on anaerobic fermentation are extremely significant,and the mixed addition has basically solved the problem of inhibition of the biological activity of anaerobic microflora by low temperature.