Flocculation - Fenton Oxidation - Map - Adsorption Process Integration Research In Waste Leachate Treatment

Landfill leachate is a wasterwater containing high concentrations of organic matter, how to treat landfill leachate effectively become a hotspot issue of enviornmental engineering. In this study, landfill leachate of ShaHe Landfill in Ganzhou City was experiment object, using combined technology as flocculation-Fenton Oxidation-MAP Precipitation-adsorption to treat it.Through orthogonal experiments, every factor and parameter for every process were optimized. The experimental results showed that the CODcr, NH4+-N and chroma were74mg/L、18.1mg/L、20, respectively after treated when their initial concentrations were1536～1696mg/L、800～830mg/L、300～400, respectively, which met the<Standard for Pollution Control on the Landfill Site of Municipal Solid Waste>(GB16889—2008).The kinetics model of Fenton oxidation was established. Its reaction series was2according to the experimental fitted results. When pH was4, the best effect of Fenton was obtained. The rate of degradation enhanced as the concentration of hydrogen peroxide increased. The concentration of Fe2+increased when the temperature raised. The activation energy of the reaction was14.22kJ/mol, which below100kJ/mol, showing that Fenton process reacted quickly.The results of SEM and XRD indicated that the precipitate has the similar crystal structure with ammonium magnesium phosphate (MAP). X fluorescence analysis indicated that the content of Mg and P was close to that of MAP. All these proved that the gengerated precipitate was MAP.The adsorptional thermodynamics of NH4+-N and CODcr upon NMBPs were studied. The reaction of the adsorption of NH4+-N and CODcr were endothermal process. As the temperature raised, the adsorption capacity of NH4+-N and CODcr upon NMBPs also enhanced, which promoted the adsorption process. The free degree of the adsorbate raised, in which probable occurred chemical adsorption. The analysis of infrared spectrum inicated that there was a P—H absorption peak at2360.0cm-1, so NMBPs had the ability of adsorbing hydrogen. The alkalization of protein lead to the weaken of C=S bond. After the adsorption, the radical contained nitrogen enhanced, this indicated that NMBPs can adsorb ammonia nitrogen.