Bioreactor landfills in developing countries: a critical review.

Landfilling is the most common method for disposing the municipal solid waste, MSW, especially in developing countries. However, the issues pertaining to land acquisition, unhygienic conditions at the landfills and environmental pollution due to intentional/accidental fires are becoming a big nuisance to the town planners and populace. In order to overcome these issues, the bio-reactor landfill, BLF, wherein degradation of the MSW and generation of landfill gases, LFG, can be accelerated, has been found to be a better MSW management strategy. However, in the recent past, BLFs have been criticized for their inefficiency and questions have been raised on their suitability as the 'right approach' to dispose the MSW. This calls for a critical evaluation of the issues pertaining to the effective functioning of BLFs such as (i) MSW decomposition characteristics, (ii) leachate recirculation system (iii) energy generation potential, of the LFG, (iv) estimation of the mining time and sustainable applications of the mined residues and (v) rigorous performance monitoring. A review of existing literature has been conducted and it is believed that such a 'fact finding exercise' would be helpful in creating guidelines related to the design, construction, operation and monitoring of a BLF, particularly in developing countries. Furthermore, based on this exercise the efficacy of BLF could be ameliorated by implementing techniques and/or methods to: (i) amend leachate characteristics for achieving decomposition of the recalcitrant fractions in the MSW, (ii) facilitate non-invasive and economical monitoring of the decomposition of the MSW, (iii) estimate accurately the time required for stabilization of the MSW and (iv) recover the resource from the mined residues