In many developing countries, around 80% of the generated Municipal solid waste goes to Open dumpsites. The urbanization has a major impact on municipal solid waste generation rates and the rate of generation is also increasing over the years. One of the major problems of concern is the contamination of ground water/surface water by the leachate generated from the open dumpsite. Leachate contains large amount of organic matter of which humic substances are the major group along with ammonia nitrogen, heavy metals, chlorinated organic, phenolic compounds, and other endocrine disruptors like phthalates (which originate from the plastic waste). Phthalates are considered as priority pollutant by US Environmental Protection Agency (EPA) & European Environmental Agency (EEA).

The research envisaged has the major objective of treatment of phthalates, organic pollutants and heavy metals using Sequential Advanced Oxidation Process based on ozonation and biochar treatment. In this research work, optimized Peroxone process (O3 + 50 mg/L H2O2) yields 82% removal of organic pollutants. Mangrove leaves such as Rhizophora and Avicennia Marina were used for adsorption experiments. In addition, to improve performance of the treatment system, Coagulation-Flocculation was used as pre-treatment before the advanced oxidation process followed by adsorption process. From our experiments, it was found that FeCl3 is more effective in coagulation-flocculation treatment. The results from this study indicate that Coagulation-Flocculation pre-treatment followed by sequential Ozone based Advanced oxidation process (O3+ 50 mg/L H2O2) followed by 1.5 g/L of Rhizophora biochar is found to be effective in removing the organic pollutants, phthalates, heavy metals, color etc. present in the leachate.