Study On Dynamic Change Of Organic Pollutants In The Municipal Landfill Leachate Process

Leachate of Liulitun landfill in Beijing was collected to research, and this paper divided three parts of research contents altogether. The first part it was to research the method of extraction, concentration and derivation etc. in the course before measuring, and capillary column stationary phase and temperature programming on GC-MS measuring, in order to offer an accurate and convenient method for the measure and analyse of organic matter in leachate. The second part it was to research the composition of organic pollutants and change regularity of different processing units in "three sectors" system which including of anaerobic, denitriding and A/O oxydation, and study on the correlation between organic pollutants and the water quality of leachate. The third part it was to study the change and mechanics of the organic pollutants composition of the recirculation system, and which compare with "three sectors" leachate treatment in landfill to appraise.The results of study were as follows:1) Compared with the three experiment groups, confirmed that adopted HP-5 chromatogram column to measure after extracting leachate samples under neutral, basic and acid conditions and deriving chemistry it in advance treatment, could improve detectable rate and credibility of organic pollutants effectively. This method was applicable for chromatography whole analyse of organic matter in leachate.2) Monitored water quality of each unit of "three sectors "leachate processing system of landfills and found 74 kinds of organic pollutants in regulating reservoir, 51 in yielding water of anaerobic pool, 43 in yielding water of air floating, 34 in yielding water after denitriding, 8 in yielding water of A/O oxidation ditch and 8 in yielding water of desilter. Anaerobic pool and A/O oxidation ditch had the best effect in removal of organic pollutants.3) Although concentration changes of water-quality index such as COD_Cr, BOD₅ and ammonia nitrogen had no significant correlation with quantity change of organic pollutants in "three sectors" system, they all exhibited decreasing trend.4 ) Auxiliary cancinogenic substances such as phenol, 2-methylphenol, 4-methylphenol and 3-methylphenol were detected in leachate. Some researches found that "three sectors" treatment could remove these organic pollutants effectively. Anaerobic pool had leading effect in remaval of phenol and 3-methylphenol. 2-methylphenol was mainly removed by A/O Oxidation ditch. Removal of 4-methylphenol needed combination of anaerobic pool, air floating and xidation ditch.5 ) There were 5 organic pollutants of ethylamine, 8-methyl-quinazoline, hexadecanoic acid, 1-aminocyclopropanecarboxylic acid, 2, 6-di-t-butyl-4-methoxy-phenyl ester and (15R)-12-hydroxy-15-methyl-lycopodan-5-one in the yielding water of "three sectors" system.6) Simulation rubbish post experiment indicated, the removal rate of organic pollutants of aerobic recirculation was 78. 4% and anaerobic recirculation's was 74.3%. The result of aerobic recirculation was better than anaerobic's. Organic pollutants composition that not got rid of was basically the same of two kinds of treatment.7) Compared with "three sectors", aerobic recirculation and anaerobic recirculation, it was found that the removal rate of recirculation was inferior to "three sectors", of which the quantity and concentration of organic pollutants remained were higher and degradation was more difficult.