Colour and Ammonia Nitrogen Removal from Stabilised Leachate Using Two Stages Coagulation: Tapioca coagulant and Electrocoagulation

Abstract

Leachate produced in municipal solid waste landfills is known to have very high concentrations of organic and inorganic pollution substances that could contaminate the surrounding. Degradation of leachate pollutants by coagulation was done conventionally by using single chemical coagulation. The application of natural coagulants, together with electrocoagulation (EC) is still at an uncertain stage. The purpose of this study was to investigate the ability of two stages of coagulation (TSC) consisting of coagulation (tapioca starch coagulant) and EC in removing colour and ammonia nitrogen from stabilising leachate under the influence of dose, leachate pH, duration, and electric current. Coagulation of tapioca starch without EC, removed 24% and 18% of colour and ammonia nitrogen, respectively. However, combining EC with coagulation at the optimum duration (20 minutes), a dose of TF (2.5 g/L), leachate pH (7), and electric current (0.15 A) achieved 37% and 61% removal of colour and ammonia nitrogen, respectively. The enhancement of colour and ammonia nitrogen were recorded by TSC. Therefore, TSC is proven able to improve colour and ammonia nitrogen removal from stabilised leachate. Indexed TermsNatural coagulant, dual coagulation, electricity, landfill leachate, solid waste