城市污水处理污泥堆肥过程中氮元素形态变化研究

Transformation of Nitrogen Forms During Composting of Sewage Sludge

以四平市污水处理厂剩余污泥为原料,木屑为调理剂进行了好氧堆肥,研究了堆肥过程中氮元素形态变化规律.结果表明,堆体中主要存在NH4+-N、V-NH3、NO3-N、TN和有机氮等N的形态,经过微生物的硝化和氨化等矿化作用,在温度和pH等外部条件影响下不断发生动态变化.堆肥初期,温度较低、pH下降,NH4+-N基本不变,NO3-N、TN和有机氮均下降,氮元素主要以水溶性小分子有机氮形式随渗沥水流失;堆肥中期,温度较高、pH升高,NH4+-N和V-NH3先升高后降低,NO3-N、TN和有机氮均呈上述趋势;堆肥后期,VNH3一直保持较高水平.在整个堆肥周期,氮元素主要以有机氮形态存在,其次是氨态氮和硝态氮.

The nitrogen element form transformation was investigated during aerobic composting using the sludge of sewage plant in Siping as raw material and sawdust as conditioner. The results indicated that NH4＋ -N, V-NH3, NOa-N, TN and organic nitrogen existed mainly nitrogen element form in the composting, and changed continuously by microbial nitration, ammonization and mineralization in the different conditions of temperature, pH and et al. During early composting, temperature and pH were low, the content of NH4 -N was basically unchanged, the content of NO3-N, TN and organic nitrogen decreased, nitrogen as water-soluble small molecule organic nitrogen forms was lost with leachate. In the middle of the compost, temperature and pH became higher, the content of NH4 -N and V-NH3 increased then decreased, and NO3-N, TN and organic nitrogen increased with time ;Compost later period, the content of V-NH3 kept highly. During the composting period, nitrogen element exist mainly organic nitrogen forms, following by NH4 -N and V-NH3.