Enhancing the Methane Yield of a Landfill Leachate Bioreactor

Our thriving modern society requires unprecedented amounts of natural resources to maintain pace with rapidly evolving standards of living in industrialized regions. Due to population growth and wide-scale urbanization, over 3.5x106 metric tons of solid wastes are produced daily around the world. In addition to land, water, and raw material strain generated by solid waste dumping, pristine resources are needed for food, energy, and potable water — instead being used through waste management. Reducing landfill leachate volume and toxicity while deriving value-added products from leachate is a sustainable alternative to traditional solid waste management. Carbon mass balances of biomass grown on salicylic acid and landfill leachate media were derived from batch data indicating that aerobic growth was half as efficient as anaerobic growth at converting organic carbon into biomass due to its open atmosphere; however, more aerobic biomass grew compared with anaerobic studies. Biomass disrupted by heat shock was found to increase methane yield compared to passive methanogenesis. An aeration-lysis-fermentation process based on the results was developed into a prototype bioreactor, which could hold further potential for mineralizing alternative waste-borne products such as organic acids and alcohols. An open-source, do-it-yourself approach is expected to accelerate the research, development, and application of sustainable waste-to-commodity concepts, which would benefit individuals with greater degrees of self-sufficiency and autonomy through energy independence and by reducing the need for waste management