Pilot Study On Treatment Of Landfill Leachate By Ammonia Stripping-biological Contact Oxidation Process

The treatment process that Liuzhou Lichonggou landfill leachate treatment plantused is “anaerobic (UASB)+the oxidation ditches of Aubert (Orbal)+chemicalprecipitation+filter (walnut+carbon+contact)+NF (NF)”. According to the first levelstandard of ‘Pollution Control Standard of Living Waste Landfill’(GB16889-1997), thisplant drains the water into the Liujiang River. In the early time, the effluent is goodenough to reach the national emission standards. With landfill "aging", the concentrationof pollutants in the leachate is gradually increasing, especially the COD and ammonianitrogen concentration, so the quality of the effluent become worse now. In this paper,the author surveyed the change of leachate’s quality, and researched the changeregulation of the leachate’s quality, then determined to do the pilot test in the leachate byusing the ammonia stripping-biological contact oxidation process units.1. According to the research, we found that the change of Lichonggou landfillleachate quality and quantity related to the change of seasonal precipitation andtemperature. In the summer with high temperatures or in the winter with lessprecipitation, the biodegradability ability of the water is the worst in one year, and thewater’s quality was the worst in the period of minimum precipitation in winter. In springand at the beginning of summer, water quality is the best in a year, and the reason issuitable temperature and precipitation.2. in the process of ammonia stripping pretreatment, the author’s research focusedon the relationship between the amount of lime and pH value, and relationship among thepH value, the influent ammonia concentration, residence time and ammonia removal.The result shows that the optimum amount is10g/L of lime. The best running value ofAmmonia stripping process is about10.0of pH value and6hours of the residence timeand over90%of the ammonia removal efficiency.In the test of Biological contact oxidation, the researcher did the biofilm culturedomestication work. And she also tested the factor of Dissolved oxygen and the organicload to research the relationship with the COD removal efficiency.3. In a pilot test, the for average removal rate of ammonia nitrogen is more than90%and the average removal rate of COD is about75%by using the ammonia stripping-biological contact oxidation process.