| The large-scale use of fossil fuels has brought great convenience to the production and life of human society,but also caused a serious threat to the natural environment.With the increasing emphasis on environmental protection,clean energy is gradually changing from auxiliary energy to main energy.Among them,hydrogen energy has become more and more favored by relevant researchers and industries in recent years due to its large energy density,wide source and no greenhouse gas production when burning.In particular,anaerobic digestion and hydrogen production has the advantages of high efficiency,convenient operation and low operating cost,and is a reliable means of hydrogen production.In this paper,the initial parameters of anaerobic hydrogen production(including sludge pretreatment method,inoculation amount and initial p H value)and the operating parameters of the reactor(including HRT,COD concentration and p H value of inlet water)were studied by using batch fermentation device and EGSB reactor at medium temperature(35±1)°C,using corn alcohol wastewater as raw materials,respectively.The conclusions of the experiment are as follows:(1)In the study of the pretreatment method,it was found that 4 pretreatment methods(aeration,strong acid,water bath heating and strong alkali)would have a certain negative impact on the anaerobic hydrogen production effect of corn alcohol wastewater,but after measuring the changes in the gas composition of each group and the volatile organic compound(VOCs)composition of the feed liquid before and after fermentation,it was found that methane was produced in the untreated group and was butyric acid fermentation,while the aeration treatment group did not detect methane and was ethanol-type fermentation,so the stability of the system was considered.It was determined that the pretreatment method of activated sludge was aeration treatment.(2)In the study of the amount of inoculation and the initial p H value,it was found that there was a value with the best hydrogen production effect in both the inoculation amount and the initial p H value,of which the optimal inoculation amount was 30%,and the optimal initial p H value was 5.5,and high or low would affect the stability and hydrogen production efficiency of the system.And the study found that the hydrogen production capacity of corn alcohol wastewater at 30%and 40%inoculation was very close,but because 40%of the inoculation produced more residual sludge and the type of hydrogen production was unstable mixed fermentation,the inoculation amount was determined to be 30%.(3)Experimental results of regulating the HRT and COD concentration of the inlet water of the EGSB anaerobic reactor showed that when the p H of the inlet water was fixed by adding sodium bicarbonate solution to 5.5,the optimal OLR of the system was54 kg/(m~3*d)(the inlet water COD was 27000 mg/L,HRT=12 h),and the maximum hydrogen content was 42.57%.The system can form a stable ethanol-type fermentation,and the average COD removal rate remains at 37.95%during stable operation.(4)By regulating the p H value of the inlet water of the EGSB anaerobic reactor(that is,reducing the amount of sodium bicarbonate solution added),it can be seen that the original solution of corn alcohol wastewater(dilution)cannot be directly used as the inlet water of the anaerobic hydrogen production system,and the inlet water p H value is too low to inhibit the metabolic activity of the anaerobic hydrogen production system,and the hydrogen production type is vaguely changed to propionic acid fermentation,which is not conducive to the system hydrogen production.In addition,in the analysis of the batch anaerobic hydrogen production experiment,the data were fitted by Cone,modified Gompertz and primary kinetics,and it was found that the Cone model had the best experimental fit effect,and the model could be combined with other models to reveal more potential laws in the process of anaerobic digestion.This paper can provide certain data support for future research and industrialization of anaerobic hydrogen production in alcohol wastewater. |
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