石灰混凝+吹脱+CO_2曝气联合对垃圾渗滤液的处理实验研究

Landfill Leachate Disposal Method Combined with Lime Coagulation, Blow-off and CO_2 Aeration

为了有效降低垃圾渗滤液中高浓度的氨氮和有机污染物,以便降低后期生化处理的污染负荷,采用石灰混凝+吹脱+CO2曝气联合法对垃圾渗滤液进行预处理,通过单因素实验研究CaO投加量、曝气时间、反应温度及气液比等因素对渗滤液中氨氮、COD以及UV254的去除效果的影响;通过正交实验研究综合处理效果最好的反应条件,并在正交实验后进行CO2曝气,以期降低实验后较高的pH和钙离子浓度。结果表明:氨氮去除率与各单因素呈正相关关系,COD及UV254的去除率与CaO投加量相关性较大。在正交试验得出的最佳混凝吹脱条件下,氨氮、COD、UV254的去除率分别能达到98.8%、60.2%、68.7%。进一步CO2曝气后,垃圾渗滤液pH由12.1降至6.8,钙离子浓度降低70.3%,COD去除率可达65.7%。

For the purpose of reducing the ammonia nitrogen and the organic pollutant with nlgn concentrauon in the landfill leachate, this text used combination treatment with lime coagulation, blow off and CO2 aeration to pretreated the landfill leachate in order to lessen the pollutant load to the biochemical treatment in the later stage. This text used single-factor experiment to discuss the impact of different factors, such as dosing quantity of CaO, aeration time, temperature and the ratio of gas and solid, on the removal efficiency of the ammonia nitrogen, COD and UV254. It also discussed the most efficient reaction condition of the comprehensive treatment effect by orthogonal experiment. The experiment also aerate with CO2 after the orthogonal experiment as to reduce the high pH and the concentration of Ca2＋. The results of this experiment indicated that, the removal efficiency of ammonia nitrogen had direct correlativity with each factors. That of COD and UV^254 had positive relationship with the dosing quantity of CaO. With the most efficient experiment condition of coagulation-blow off which obtained from the orthogonal experiment, the removal rate of the ammonia nitrogen, COD and UV254 could get 98.8%, 60.2%, 68.7% respectively. After the further aeration with C02, the pH of the garbage percolate fall to 6.8 from 12.1. The removal rate of the concentration of Ca2. was 70.3% and that of COD was 65.7%.