Treatment of wastewater with landfill leachate using a sequencing batch reactor followed by a granular activated carbon

Abstract Landfill leachate is an environmental hazard requiring appropriate management and treatment. It is commonly co-treated with municipal wastewater at wastewater treatment plants. However, this approach produced environmentally harmful components associated with the increase in the color of the effluent and elevated levels of dissolved organic matter (DOM). This study aimed to assess the efficiency of applying a sequencing batch reactor (SBR) followed by a granular activated carbon (GAC) column for the co-treatment of wastewater and leachate, where the system was monitored for 490 days. No previous studies have utilized a biological process followed by adsorption to treat wastewater with leachate over an extended period. The addition of landfill leachate increased the dissolved organic carbon (DOC) content, true color, UV 254nm absorbance, and specific ultraviolet absorbance (SUVA) of the raw wastewater. The integrated SBR-GAC system demonstrated a high treatment efficiency, achieving 90% DOC removal, and of 75% and 67% reductions in UV 254nm absorbance and true color were observed, respectively. SUVA increased with the addition of landfill leachate and after SBR treatment, indicating the accumulation of recalcitrant organic matter in the effluent. SUVA subsequently decreased following GAC treatment, suggesting the effective removal of refractory compounds. The acute toxicity of the effluent was reduced in the SBS-GAC process. The results show that this combined system is an efficient and effective method for treating wastewater and landfill leachate.