混凝+芬顿法对中晚期垃圾渗滤液色度去除

垃圾渗滤液经一般生化处理后色度很大。对混凝和芬顿法结合深度处理垃圾渗滤液对色度去除进行了研究。混凝段通过中心复合设计(简称CCD)和响应面方法(简称RSM)分析了混凝的色度去除率的响应特征,建立了实际因素的最终方程模型:Y(色度去除率,%)=-553.40+73.74A+229.06B+0.38AB-34.16A2-22.67B2,(Y、A、B分别代表色度去除率、投加量和pH)并对絮凝条件进行优化,得到混凝反应的最佳优化条件:投加量1.11 g/L,pH 5.06,及在此条件下的去除率67.2%。在芬顿段,将芬顿反应对水中亲水性有机物相对含量(UV254)与对色度的去除特征相结合进行了研究,证明色度的去除跟该类有机物的去除有关,色度去除率最优值条件选择为H2O2/COD=1.0,Fe2+/H2O2=0.35∶1,而初始pH=2.5时对色度的去除达到99%以上。整个工艺出水可达到达标排放标(GB16889-2008)。

Color removal in aged landfill leachate by process of coagulation-flocculation and Fenton

Older landfill leachate is characterized by high color after general biological treatment. In the present study, the advanced treatment coagulation-flocculation combined with Fenton oxidation to remove color from landfill leachate was investigated. In the coagulation unit, color removal rate as a response was analyzed and process conditions were optimized via response surface methodology (RSM) using central composite design (CCD). The final equation in terms of actual factors was established: Y=-553.40+73.74A+229.06B+0.38AB-34.16A²-22.67B² (Y,A,B for color removal rate, dosage and pH, respectively), and the optimum conditions were dosage of 1.11 g/L,pH of 5.06, and the color remove rate of effluent was 67.2%. Then, the removal features of the color accompanied with the removal features of hydrophilic organic matter(indicated by UV₂₅₄) in Fenton unit was researched, and it was proved there should be a certain relationship between color removal and hydrophilic organic matter removal. The optimum conditions in Fenton unit were H₂O₂/COD=1.0,Fe²⁺/H₂O₂=0.35:1,and the color removal rate could be achieved above 99% when initial pH=2.5.The final effluent of the whole process met the standard for discharge (GB16889-2008).