温度、pH值对城市垃圾中有机碳溶解及其降解特性的影响

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

通过实验及数值模拟的方法,研究了不同温度和 pH 值条件下有机碳的溶解动力学特性.结果表明,提高溶液温度有利于加速易溶解有机碳的溶解速率,但不能提高固相有机碳总的溶解量.降低溶液 pH 值有利于固相有机碳的溶解.实验样品在所有测试环境条件下,有机碳溶解速率为0.05-0.22m3/（kg·h）；易溶解有机碳占总可溶解性有机碳百分比为30%-50%；易溶解有机碳溶解速率为14-65h-1,比难溶解有机碳溶解速率高出大约3个数量级.水溶性有机碳生物可降解性实验表明,79%以上水溶性碳难以在厌氧条件下被原生菌降解.

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 0.05-0.22m3/（kg·h）, while rapidly dissolving fraction of organic carbon accounted for 30%-50% of the total and its dissolution rates ranged from 14h-1to 65h-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.