Sustainability Analysis of Physical, Chemical, and Biological Treatment Technologies for Landfill Leachate Using Life Cycle Assessment

ABSTRACT Landfill leachate, a highly complex and hazardous wastewater, poses significant environmental and public health risks due to its diverse composition of organic, inorganic, and heavy metal contaminants. Effective landfill leachate treatment is critical to mitigating its ecological impacts and environmental sustainability. This study utilises Life Cycle Assessment (LCA) to evaluate the sustainability of three leachate treatment methods: Reverse Osmosis (RO) as a physical treatment, Advanced Oxidation Processes (AOPs) as a chemical treatment, and Aerobic Treatment as a biological approach. Conducted using OpenLCA software (version 2.3.0), the analysis adopts a cradle-to-grave system boundary, assessing environmental impacts across key metrics such as global warming potential (GWP), eutrophication, acidification, energy demand, and resource depletion with the impact method ReCiPe 2016 2_1_3 used on the software. The study highlights significant findings, including Global Warming Potential (GWP) values of 4.71487 kg CO₂ equivalent for RO, 4.94699 kg CO₂ equivalent for AOP, and 9.6096 kg CO₂ equivalent for the Aerobic Process. The assessment identifies key environmental impact categories such as ecotoxicity, eutrophication, energy demand, and resource depletion, revealing that upstream processes dominate the ecological burdens of RO and AOP. The results revealed that RO exhibited superior contaminant removal efficiency (90%) (COD, BOD, and ammonia) but incurred significant environmental burdens due to its high-energy consumption and brine disposal challenges. AOPs demonstrated effective degradation of recalcitrant organic pollutants but were hindered by substantial greenhouse gas emissions and chemical residuals, leading to higher toxicity and eutrophication potentials. Aerobic treatment was the most sustainable option, with moderate energy requirements of 33kWh/m3 and lower environmental impacts, although sludge management remained a concern. Comparative analysis identified RO as the most effective for stringent water quality needs, while aerobic treatment emerged as the most environmentally sustainable. AOPs, despite their high treatment efficacy, require optimisation to address their environmental shortcomings. This research highlights the trade-offs between efficiency and sustainability in landfill leachate treatment and underscores the importance of integrated, hybrid approaches to balance these factors. The findings provide critical insights for policymakers and waste management practitioners, advancing sustainable solutions for landfill leachate management.