Influence of ventilation rate on aerobic fermentation process of food waste with microbial inoculant addition
Ventilation rate is an important limiting factor that affects the quality of aerobic fermentation products of food waste and is vital to the success of aerobic fermentation.By adjusting the ventilation rate during the fermentation process,the oil degradation and the generation and accumulation of organic acids in food waste were controlled,and the limited acidification of the fermentation process could be achieved.It not only reduced the volatilization and loss of NH3,but also improved the quality of fermentation products.The results of this study showed when the ventilation rate of aerobic fermentation piles increased,the peak temperature of the fermentation piles increased,but the high-temperature period was shortened,with the organic matter degradation rate and pile maturity firstly increasing and then decreasing.As the ventilation rate was 0.2L/(L·min),the aerobic fermentation efficiency of food waste pile was better.The greater the ventilation rate during the aerobic fermentation of food waste,the lower the accumulated volatilization of NH3.When the ventilation rate was 0.1 L/(L·min),the high temperature period was longer,which was not conducive to the growth and reproduction of nitrifying microorganisms for the conversion of NH3 to NOx-,and NH3 emissions were the highest.When the ventilation rate was 0.3L/(L·min),the high-temperature period was the shortest,and water loss of piles was severe,while organic matter degradation was not complete,and NH3 volatilization was also the lowest.Compared with the absence of self-made oil removal microbial inoculants(ORMI),the addition of ORMI effectively enhanced the aerobic fermentation of food waste.At the end of aerobic fermentation,the oil degradation rate,seed germination index and total nutrient content were increased by 23.08%,29.48%and 7.36%,respectively.The ventilation rate affected the activities of relevant microorganisms and lipase enzyme,further influenced the degradation of oil and accumulated volatilization of ammonia,and ultimately promoted the maturity and total nutrient content of the aerobic fermentation products.