Impacts of aeration and active sludge addition on leachate recirculation bioreactor

Enhanced solid waste stabilization in aerobic landfills using low aeration rates and high density compaction

“…Hence, the concept of aerobic stabilization/degradation of landfill waste has been targeted in a number of recent studies representing various practices and techniques, such as intermittent/continuous aeration, leachate recirculation with/without treatment and sludge addition Erses et al, 2008;Giannis et al, 2008;He et al, 2011;Jun et al, 2007;Nikolaou et al, 2010;Rendra et al, 2007). While the basic understanding of aerobic landfilling operations is well covered in the literature on composting work and despite the similarity in the biological regime prevailing in waste treatment approaches, the operating parameters from composting studies need to be examined and refined to fit a landfill environment.…”

Determinants of Optimal Aerobic Bioreactor Landfilling for the Treatment of the Organic Fraction of Municipal Waste

“…While temperature can be controlled by moisture content, the system responds faster to changes in the aeration rate (Rich et al, 2007;Giannis et al, 2008;Borglin et al, 2004). In general, high temperatures may help in destroying pathogens, accelerating biodegradation, causing evaporation of leachate and reducing its quantity (Kumar et al, 2011;Jun et al, 2007;Giannis et al, 2008;Rich et al, 2007). Yet, excessively high temperatures may inhibit certain biological reactions (particularly nitrogen conversion) while together with aeration, might lead to explosive mixtures; however, careful monitoring of methane and moisture content could help minimize the risk of such incidents (Berge et al, 2005).…”

“…Last but certainly not least, aeration aims at providing the oxygen supply to maintain aerobic conditions and accelerate the aerobic degradation of the waste (Erses et al, 2008;Jun et al, 2007;Rendra, et al, 2007). It also serves to mitigate explosion hazards by adjusting oxygen-methane mixture composition to safe levels.…”

“…* Optimum range(Qiu et al, 2010;Sang et al, 2009;Erses et al, 2008;Giannis et al, 2008;Jun et al, 2007;Rendra, et al, 2007;Rich et al, 2008;Mertoglu et al, 2006;Ritzkowski et al, 2006;Berge et al, 2005;Borglin et al, 2004;Agǎdaǧ and Sponza, 2004;Das, et al, 2002; ECS, 1999;Hanashima, 1999;Hudgins and Harper, 1999).Stabilization criteria that help in defining an endpoint for active aeration processes constitute operational guidelines that target low residual gas generation, low levels of organics and nitrogen in leachate, and low settlement rates(Table 5).4. ECONOMIC CONSIDERATIONSEconomically, the viability of the aerobic bioreactor landfill technology is site-specific and highly dependent on equipment specifications to be used as well as boundary conditions and requirements such as oxygen demand, landfill height, leachate infrastructure, as well as air injection and gas extraction systems among other factors.…”

Long-term moisture measurements in large-scale bioreactor cells using TDR and neutron probes

“…Landfill bioreactor engineering thus mainly focuses on the way to increase the moisture of the waste material. Moisture is generally added in the form of leachate, which is injected or recirculated in the landfill cells, and bioreactors hence offer an alternative and cheap leachate treatment option [1,8,9]. A continuous monitoring of MSW moisture seems essential to operate the landfill and this is only possible when real-time and non-destructive moisture content measurements are made.…”