The Study On The Effect Of Detergent On Anaerobic Digestion Of Food Waste

The food waste prouction in our country is huge,and with economic,environmental,social and other comprehensive benefits,we can use the anaerobic digestion technology to convert it into clean,renewable biomass energy?bio-gas?.The process of collecting food waste will be dipped in detergent,which will have an impact on the process of the subsequent anaerobic digestion.In this paper,eight groups of different gradient detergent concentrations were designed:0 mg/L,100 mg/L,200 mg/L,300 mg/L,400 mg/L,800 mg/L,1200 mg/L and 1600 mg/L,the effects of the main metabolic types,volatile organic acids?VFA?and gas production on anaerobic fermentation were studied.Under the conditions set in the experiment,the following conclusions are obtained:1.Food waste anaerobic digestion process based on butyric acid fermentation,rather than ethanol type.There was no significant difference in the total organic acid?VFA?content between the two groups except the detergent concentration of 800mg/L and the control group without detergent.There were significant differences in the groups above 800 mg/L.The changes of VFA were increased first and then decreased in the experimental group with the concentration of 0 mg/L,400 mg/L,800mg/L,1200 mg/L and 1600 mg/L.In the experimental range,the higher the concentration of detergents is,the greater the concentration of total organic acids is,and they are positively correlated.With the increase of detergent concentration,0mg/L,400 mg/L,800 mg/L,1200 mg/L and 1600 mg/L,the peak time of acetic acid concentration in each group lagged behind,and also the peak values of acetic acid are increased,and they are positively correlated.The curve of the concentration of butyrate is saddle-shaped.In addition to the 1600 mg/L experimental group,the other groups reached the peak at 5^th day.The peak of butyric acid increased with the increase of detergent concentration.In the experimental range,the higher the concentration of detergent is,the greater the concentration of butyric acid is,and they are positively correlated.2.The results of gas production showed that there was no significant difference between the biogas production and the biogas production in the five groups with the detergent concentration of 400 mg/L and the control group.The biogas production at800 mg/L was significantly different from that in the control group,while the cumulative biogas production was not significantly different from that of the control group.The test group with a detergent concentration of 1200 mg/L showed a significant inhibition in biogas production and accumulated biogas production compared with the control group.The test group with a detergent concentration of1600 mg/L was significantly inhibited the anaerobic fermentation of biogas production and total biogas production.The cumulative biogas production in the 1200mg/L and 1600 mg/L test groups was 21%and 24%lower than in the control group,respectively.The anaerobic fermentation of methane from the kitchen was the same as above.The difference was that the accumulated methane production in the 1200 mg/L and 1600 mg/L test groups was 22%and 33%lower than the control group,respectively.In the experimental range,each group of test groups has two stages of gas production peak.With the increase of detergent concentration,the peak value of gas production in the two stages showed a decreasing trend,and the peak gas production time was delayed and the accumulated gas production decreased.The fermentation cycle is prolonged and is not conducive to engineering promotion.3.The production of gas and methane is inhibited significantly or not which does not only depend on the main component of the detergent SDBS,but also the synergistic effect of the other ingredients inside the detergent and SDBS.