Method Development for Aquatic Humic Substance Isolation and Its Application to Landfill Leachat

Municipal solid waste landfills generate leachate which is a mixture of the percolated rainwater and moisture from the solid wastes. Leachate needs to be treated as they can leach through the soil subsurface and contaminate soil and groundwater. Cotreatment with sewage in publicly owned treatment works (POTWs) is the most preferred disposal method for leachate. However, bio-refractory materials like humic substances interfere with biological treatment process in POTWs and quench the UV254 radiation, hence, impeding the UV disinfection process. The characterization of humic substances in landfill leachates are important to understand the UV254 quenching properties of leachates. Organic content of the leachates from the elevated temperature landfills are above typical range. Therefore, treatment of leachates from elevated temperature landfills (ETLFs) are more difficult. A method has been developed in this study to isolate humic substances from landfill leachates and applied on the leachates from elevated temperature landfills (ETLFs). Leachates have been biologically treated and humic substances have also been isolated from the treated leachates to understand the biodegradability of the humic substances. Leachates in methanogenesis phase and humic acids in all the leachates showed the most potential for UV254 absorbance.