城市污泥有机氮矿化动态及其影响因素的研究

MINERALIZATION OF ORGANIC NITROGEN IN ANAEROBICALLY DIGESTED SLUDGE

采用好气培养间歇淋洗法研究了厌气消化脱水污泥的有机氮矿化动态．在污泥用量为３％—２４％范围内，污泥有机氮１４周矿化率可达３１％—６５％，前６周矿化相对较快，随后减慢，其矿化动态可用经典一级动力学方程来描述．污泥用量小于６％时，随污泥用量增加，有机氮矿化率明显减小；污泥用量在６％—２４％时，污泥用量对有机氮矿化率的影响较小，但温度对有机氮矿化率影响相当明显．

Mineralization of organic N is one of the principle factors affecting the annual amount of sewage sludge applied to crop land.The mineralization of organic nitrogen in anaerobically digested sludge from secondary sewage traetment plant was studied using a procedure of periodic leaching of soil sludge sand mixtures.31 to 65% of organic nitrogen in the sludge was mine ralized in the calcareous heavy loam soil amended with sludge at application rate from 3% to 24% during a incubation period of 14 weeks.Sludge exhibited a rapid,initial release of inorganic N,followed by a relatively constant rate of mineralization from weeks 6 to 14.The mineralization dynamics of organic N could be described by a classical first order kinetics: N m= N 0(1-e - Kt ).Net mineralization rates of organic N increased as temperature increased or sludge addition decreased when sludge were added to soil at rates ranging from 0 to 6%,but the amount of N mineralization were similar (31% 38%) at application rates more than 6%.