Malodor Producing Mechanism And The Study On Its Dynamic Changes In Landfill

According to the measurement and the experiments in Asuwei municipal landfill, it is studies how H2S is produced and changes, which shows how to control the malodor. The followings are included.1. The analysis on the garbage in the open air and the content of air in different distance shows that the malodor is mainly made up of compounds with sulfur, chlorine, benzene and amine. The compounds with sulfur and amine are in high percent. Most malodor with sulfur in methane collecting pipe is H2S.2. Based on the pollution monitoring during the pre-period and post-period of the methane reformation project in Asuwei municipal landfill, the causes of H2S and the influence on it were analyzed in the northern plain landfill. The result shows that during the pre-period, when a fresh filled municipal garbage reaches 2m, H2S quantity density changed greatly in different quarters, and its peak density of H2S appearing in September, the third quarter, is 179.1mg/m3; when a fresh filled municipal garbage is 0.5m high, H2S density changes little in different quarters, with its peak 21.8mg/m3. That is caused by the content of water in different quarters and the height of fresh garbage. At the end of the project (2003.6 - 2003.7), the changing trend of H2S density in leachate collection wells is related to that of the surface evaporation. H2S density changes are decided by the average temperature of 38# inside the garbage and pH in declination process. H2S mainly emits from the filling area in the landfill. Therefore, it is important to control the height of fresh solid waste in a year in the municipal landfill for controlling the changes of in quarters H2S quantity density and its peak.3. In the experiment, the rotten garbage column disposes of the leachate in adjustive pool . Based on the result of CODcr and NH3-N in the leachate, the experiment tries to study the changes of H2S in the top of the column. The result shows that when the density of the column is 1.09t/m3, the leachate moves down clearly in vertical direction. When water-load is 4cm, 6cm, 8cm and 10cm each time, the disposing rate of CODcr is stable, 82.39% on average, 90.1% the highest; the average disposing rate of NH3-N is 549.3mg/l and changes between 415mg/l and 700mg/l. The highest disposing rate of CODcr in the process of leachate recirculation is only 11.5%, NHs-N only 11.8%.If the water-load is between 39.81/m2 and 99.51/m2 each time, the density of H2S changes slightly, as the same level before recirculation. The highest density is 1.115mg/m3. So, the leachate recirculation has small effect on the density of H2S.