Municipal Landfill Leachate Treatment and Sustainable Ethanol Production: A Biogreen Technology Approach

Abstract

Sustainable material sources are an important agenda to protect the environment and to meet human needs. In this study, Scenedesmus sp. was used to treat municipal landfill leachate via batch and continuous cultivation modes to protect the environment and explore sufficient biomass production for bioethanol production using Saccharomyces cerevisiae. Physicochemical characteristics of leachate were determined for the phases before, during, and after the process. Batch and continuous cultivation were used to treat raw leachate to determine optimum conditions for treatment. Then, the biomass of Scenedesmus sp. with and without sonication was used as a substrate for ethanol production. Sonication was carried out for biomass cell disruption for 20 min at a frequency of 40 kHz. Through batch cultivation mode, it was found that pH 7 was the optimum condition for leachate treatment. Continuous cultivation mode had the highest removal values for COD, phosphorus, and carbohydrate, namely 82.81%, 79.70%, and 84.35%, respectively, among other modes. As for ethanol production, biomass without sonication with 9.026 mg·L−1 ethanol, a biomass concentration of 3.300 µg·L−1, and pH 5 were higher than biomass with sonication with 5.562 mg·L−1 ethanol, a biomass concentration of 0.110 µg·L−1, and pH 5. Therefore, it is evident that the leachate has the potential to be treated by Scenedesmus sp. and converted to bioethanol in line with the concept of sustainable materials.

Keywords

• leachate treatment
• <i>Scenedesmus</i> sp.
• <i>Saccharomyces cerevisiae</i>
• ethanol
• biomass
• bioreactor