| Abstract: | Landfills are facing a challenge in removal of heavy metals and recalcitrant organics from leachate. Even if leachate is sent to a municipal wastewater treatment plant (WWTP), metals and organics (natural organic matter, including humic and fulvic acids), and per- and poly-fluoroalkyl substances, or PFAS, must first be removed. Adsorbents have proved to effectively remove heavy metals and organics, using fewer chemicals and energy than many competing techniques (e.g., advanced oxidation processes). Adsorbents made from wastes like rice husk (RH), rice husk ash (RHA), sewage sludge (SS), and sewage sludge char (SSC) are more sustainable than traditional activated carbon, which is made from coal. Reusing waste materials reduces waste disposal costs and is typically cheaper. A single type of adsorbent, however, is not effective in removing the variety of heavy metals and organics present in leachate. The principal goal of this project is to develop a multiple sorbent mixture, “MultiSorb," from readily available waste materials to cost-effectively remove different types of pollutants from leachate. LEAF Method 1314 showed release of heavy metals and organics from RHA and SSC to be within drinking, irrigation, and aquatic standards/guidelines nationally and internationally, except for slightly elevated arsenic levels from RHA. |