A real-wastewater strategy using tropical agro-waste bioadsorbents for landfill leachate remediation

ABSTRACT Landfill leachate poses a serious environmental challenge due to its complex mixture of heavy metals and organic pollutants, while conventional treatment technologies are often costly and energy-intensive. Agro-waste bioadsorbents (AWBs) offer a sustainable alternative by utilizing low-cost and environmentally friendly materials. This study evaluated four AWBs – rice husk, sawdust, corn cob, and banana peel – using real landfill leachate from the Talumelito landfill, Gorontalo, Indonesia. A continuous-flow column system with ten filter cartridges was applied to simulate practical treatment conditions. Effluent quality was assessed based on total suspended solids (TSSs), Fe, Cu, Cr, Pb, pH, biological oxygen demand (BOD), and chemical oxygen demand (COD). All AWBs achieved complete removal of Cr and near-complete removal of Pb, while sawdust (64%) and banana peel (56.8%) showed the highest Fe reduction. In contrast, Cu removal was ineffective and often negative, indicating metal leaching. Organic parameters exhibited mixed behavior, with COD increasing across all materials due to the release of soluble organic compounds. Overall, AWBs are selectively effective for removing heavy metals in low-metal-strength leachate, but are limited in their ability to remove organics, highlighting the need for pretreatment or integration with complementary treatment processes.