城市固废好氧加速稳定及碳氮迁移试验研究

选取上海市老港填埋场3~4a垃圾做室内强制通风单元体试验,监测固、液、气三相成分变化,并对有机污染负荷的削减规律以及碳、氮元素的迁移规律进行分析与研究.结果表明,固相纤维素/木质素(C/L)值从初始0.8降至0.4以下,固相中BDM、TOC、TN也有降低,固相指标降解速率呈现前期大后期小的特点,且上层垃圾降解程度更大.液相pH值、EC维持在固定区间,有机污染负荷得到了极大地削减,在整个试验期间,TOC、COD、BOD降解率分别达97%、94%、94%,TN、NH₄-N的降解率分别达到95%、94%.试验期间,累积CO₂释放量6.7kg,累计N₂释放量0.75kg.C/L值、降解稳定化归一指标β可作为固相垃圾稳定化程度判定指标,BOD/COD、NH₄-N/TN值可作为液相中可降解物质稳定化程度判定指标.根据质量守恒原理,对试验过程中碳、氮元素的迁移进行了分析.固相累积损失C质量2.09kg,液相累积流失C质量0.14kg,CO₂累积释放C质量1.83kg.固相累积损失N质量0.62kg,液相累积流失N质量0.08kg,N₂累积释放N质量0.75kg.降解基本结束后,固相中仍然残存着大量的不可降解或者难降解的含碳及含氮化合物.

Experimental study on aerobic accelerated stabilization and carbon and nitrogen migration of municipal solid waste

The 3-4-year-old municipal solid waste (MSW) of Shanghai Laogang landfill was selected for the indoor forced ventilation unit test. The changes of solid, liquid, and gas components were monitored, and the reduction law of organic pollution load and the migration law of carbon and nitrogen were analyzed and studied. The results show that: The value of cellulose/lignin (C/L) in the solid phase decreased from the initial 0.8 to less than 0.4, BDM, TOC, and TN in the solid phase also decreased. The degradation rate of solid index was large in the early stage and small in the late stage, and the degradation degree of waste in the upper layer was greater. The pH and EC of the liquid phase were maintained in a fixed range, and the organic pollution load has been greatly reduced. During the whole test period, the degradation rates of TOC, COD, and BOD reached 97%, 94%, and 94% respectively. The degradation rates of TN and NH₄-N reached 95% and 94% respectively. During the test, the cumulative CO₂ release was 6.7kg and the cumulative N₂release was 0.75kg. C/L value, degradation stabilization normalization index β can be used as indexes to judge the stabilization degree of MSW. BOD/COD and NH₄-N/TN values can be used as indicators to determine the stability of degradable substances in the liquid phase. According to the principle of mass conservation, the migration of carbon and nitrogen during the experiment was analyzed. The cumulative loss of carbon mass in the solid phase was 2.09kg, the cumulative loss of carbon mass in the liquid phase was 0.14kg, and the cumulative release of carbon mass in CO₂ was 1.83kg. The cumulative loss of nitrogen mass in the solid phase was 0.62kg, the cumulative loss of nitrogen mass in the liquid phase was 0.08kg, and the cumulative release of nitrogen mass in N₂was 0.75kg. After the degradation, there are still a large number of non-degradable or refractory carbon and nitrogen compounds in the solid phase.