Effects of Available Carbon on Turnover and Loss of Nitrogenous Compounds during Composting of Food Wastes

[Objective] The rule about ammonia volatilization,nitrogen compounds turnover and nitrogen loss amount during the composting of food wastes were investigated.[Method] The ventilation was 0.03 m3/(kg·h).Dry mass ratio of food wastes to available carbon was different.Three kinds of ratio(defined as T0,T1 and T2) were used and they were 1.0∶0,1.0∶0.2 and 1.0∶0.5,respectively.[Result] At the end of composting,the accumulative amount of ammonia emissions from food wastes of the three experimentations as T0,T1 and T2 was 8.50,8.28 and 0 g/kg,respectively.The concentration of total nitrogen of T0,T1 decreased by 17.1%,10.2%,while that of T2 increase by 6.7%.Organic nitrogenous content decreased by 24.5%,23.2% and 5.3%.Ammonia concentration increased by 69.4%,761.7%and 2 057.7% in treatment T0,T1 and T2.The lost amount of nitrogen was 35.4%,42.1% and 38.1% of the initial total nitrogen amount.Ammonia volatilization was account for 69.2%,58.3% and 0% of the total nitrogen losses.In treatment T0 and T1 the nitrogen losses of food wastes composting were attributed mostly to ammonia volatilization,and in treatment T2 they were attributed mostly to organic compound directly volatilization.[Conclusion] Available carbon reduced the ammonia volatilization during the composting of food wastes,increased the total nitrogen content of composting material,but didn't reduce nitrogen losses.