Anaerobic Digestion of Municipal Solid Wastes

Abstract

This paper discusses the present state of municipal solid waste (MSW) disposal in Brazil , focusing on the particular situation in the City of Sao Paulo, and indicates the future trend of the anaerobic digestion approach for this residue. Also, some results, representative of several studies developed at IPT on anaerobic digestion of MSW mixed with primary sewage sludge, are presented. These studies were conducted using agitated reactors of 2 or 8 liters capacity, continuously operated at 35°C and in the pH range 6.8 to 7.2. The studies were on: start-up of reactors, MSW to sewage sludge ratio, organic loading rate and hydraulic retention time. The results presented in this paper indicate the great interest in achieving anaerobic digestion of MSW in presence of sewage sludge, utilizing reactors with high solids content, which is the approach already observed, and certainly will be developed in the future.

Preliminary experimental results of Sewage Sludge (SS) Co-digestion with Palm Oil Mill Effluent (POME) for Enhanced Biogas Production in Laboratory Scale Anaerobic Digester

“…According to previous works reported, it is derivable that anaerobic digestion of SS as a single substrate is possible, but the amount of biogas produced from this process will be lower than that compared to SS co-digested with other high organic material sludge. The results obtained as in Figure 2 seem to comply with Schmidell's studies which show that a substrate digested individually will produce lesser biogas compared to mixed sludge's [8]. …”

Co-digestion of mixed industrial sludge with municipal solid wastes in anaerobic simulated landfilling bioreactors

“…It was observed that the reactors containing mixed industrial sludge exhibited better organic matter reductions. Similarly, in the study realized by Schmidell et al [26]; the organic matter reduction decreased when the industrial sludge quantity was increased. The settlements efficiencies were 73, 83 and 90% in control Run 1 and Run 2 reactors, respectively.…”

“…Different suggestions were reported about the effects of sewage and industrial sludge on the VFA concentrations in leachate samples. Schmidell et al [26] reported that a high quantity of the sewage sludge within the solid waste reactor has a low VFA concentration. On the other hand, in the study carried out by Pohland and Gould [11], the VFA concentration of the reactor receiving industrial sludge was higher than that of the control reactor.…”

Comparison of Temperature‐Phased and Two‐Phase Anaerobic Co‐Digestion of Primary Sludge and Municipal Solid Waste

“…Co-digestion of primary wastewater sludge (PS) and the organic fraction of municipal solid waste (OFMSW) has been studied extensively since the early 1970s (Cecchi et al, 1997;Diaz and Trezeka, 1977;Diaz et al, 1974;Isaacson et al, 1988;Kayhanian and Rich, 1996;Klein, 1972;Schmidell et al, 1986;and Stenstrom et al, 1983). The research described herein compares temperaturephased and two-phase anaerobic digestion processes for the treatment of municipal solid waste mixed with PS.…”