Influence of temperature and pH on dissolution and biodegradation kinetics of water extractable organic carbon from municipal solid waste

The organic carbon dissolution behavior under different temperatures and pH value conditions was investigated by means of both experiments and numerical simulation. Increasing leaching temperature was beneficial for accelerating the dissolution rate of rapidly dissolving organic carbon fraction. However, the dissolution amount of organic carbon was not improved under high temperature conditions. On the other hand, lower leaching pH values were favorable for dissolving organic carbon from solid phase. Under different leaching conditions, the dissolution rates of organic carbon were in the order of 0.05~0.22 m³/(kg·h), while rapidly dissolving fraction of organic carbon accounted for 30%~50% of the total and its dissolution rates ranged from 14 h^-1 to 65 h^-1 (orders of magnitude were three times higher than that of slowly dissolving fraction of organic carbon). Moreover, the incubation experiment results indicated that more than 79% of the water extractable organic carbon was hard to be decomposed by in-situ bacteria under anaerobic condition.