Optimisation of the two-phase dry-thermophilic anaerobic digestion process of sulphate-containing municipal solid waste: population dynamics.
Microbial population dynamics and anaerobic digestion (AD) process to eight different hydraulic retention times (HRTs) (from 25d to 3.5d) in two-phase dry-thermophilic AD from sulphate-containing solid waste were investigated. Maximum values of gas production (1.9 ± 0.2 l H2/l/d; 5.4 ± 0.3 l CH4/l/d and 82 ± 9 ml H2S/l/d) and microbial activities were obtained at 4.5d HRT; where basically comprised hydrolysis step in the first phase (HRT=1.5d) and acidogenic step finished in the second phase as well as acetogenic-methanogenic steps (HRT=3d). In the first phase, hydrolytic-acidogenic bacteria (HABs) was the main group (44-77%) and Archaea, acetogens and sulphate-reducing bacteria (SRBs) contents were not significant; in the second phase (except to 2d HRT), microbial population was able to adapt to change in substrate and HRTs to ensure the proper functioning of the system and both acetogens and Archaea were dominated over SRBs. Decreasing HRT resulted in an increase in microbial activities.
Department of Environmental Technologies, Faculty of Marine and Environmental Sciences (CASEM), University of Cádiz, Pol, Río San Pedro s/n, 11510 Puerto Real, Cádiz, Spain. Electronic address: soraya.zahedi@uca.es.
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Romero
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D000693:Anaerobiosis; D001105:Archaea / Q000254:growth & development*; D001419:Bacteria / Q000254:growth & development*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002947:Cities; D006859:Hydrogen / Q000032:analysis; D008697:Methane / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D062611:Solid Waste / Q000032:analysis*; D013431:Sulfates / Q000302:isolation & purification*; D013696:Temperature; D014865:Waste Disposal, Fluid
D009930:Organic Chemicals; D062611:Solid Waste; D013431:Sulfates; D006859:Hydrogen; D008697:Methane
Hydrogen production; Methane production; Population dynamic; Sulphide production; Two-phase dry-thermophilic anaerobic digestion