Comprehensive review on technological advances in landfill leachate management: Physico-chemical characteristics, treatment methods and cost analysis

Globally, the increase in solid waste generation rate has been a growing concern, posing significant environmental and public health risks. Engineered landfills are common approaches for their disposal, however, it generates toxic by-products in form of landfill leachate and gas emissions. Therefore, these landfill sites demand standardized handling protocol and treatment facilities for leachate treatment. Current research on landfill leachate management reveals notable gaps, particularly in understanding technological feasibility, cost-effectiveness, and practical on-site operational challenges. This review article provides valuable insights on leachate characteristics from different categories of landfill sites, particularly focus on those designated for municipal solid waste and hazardous waste. This study also includes operational phenomena, feasibility, advantages and limitations for wide category of conventional and advanced leachate treatment methods. The conventional methods were classified as physico-chemical (coagulation-flocculation, adsorption and chemical oxidation) and biological processes. Advanced treatment methods include advanced oxidation processes (AOPs), membrane filtration, and integrated/hybrid systems. It was evident that advanced methods (>80 %) had higher performance efficiency in comparison to conventional methods (50–70 %). For an instance, AOPs, membrane filtration and integrated/hybrid systems achieved mean chemical oxygen demand removal efficiency of 90 %, 85 %, and 95 %, respectively. Finally, a comprehensive cost–benefit analysis was performed to assess economic viability of above discussed treatment methods. Comparative analysis showed that cost affiliated to leachate treatment was on higher side for integrated methods (3–14 $/m 3 ) than individual methods (1.3–2.5 $/m 3 ). Overall, this review bridges critical knowledge gaps and offers actionable insights to support more effective landfill leachate management by practitioners, policymakers, and researchers. • MSW and HW landfill leachate characteristics and treatment options discussed separately. • Integrated treatment strategies outlined for HW landfill leachate. • Economic assessment was performed for various treatment options. • Advanced methods like membrane filtration technologies and AOPs outperformed well. • Integrated treatment strategies best suited for HW landfill leachate.