Effects of pH on methanogenesis and sulphate reduction in thermophilic (55°C) UASB reactors

Influential Parameters on Biomethane Generation in Anaerobic Wastewater Treatment Plants

“…On the same concept, but using solid waste substrate, Bae et al concluded that the continuous addition of active methanogenic population into the anaerobic digester by sludge recycling was effective for rapid and significant methane gas recovery (Bae et al, 1998). Visser et al also reported that effluent recirculation (of factor 6.7) was necessary in order to improve mixing and to ensure sufficient buffer capacity of extreme pH situation (pH 2-4) (Visser et al, 1993). …”

“…In order to maintain high levels of biomass inside the digester, several strategies have been adopted by many researchers. Among those, sludge recycling (Visser et al, 1993;Setiadi et al, 1996;Bae et al, 1998;Faisal & Unno, 2001;Busu et al, 2010), is probably the simplest strategy to increase the biomass concentration in the digester. Busu et al conducted a simple experiment on anaerobic treatment of POME and the sludge was recycled at 6 m 3 /d with different feeding strategies.…”

“…The optimum pH range for selected methanogens (Gerardi, 2003;Steinhaus et al 2007) reactor failure or underperformance simply due to pH reduction caused by accumulation of high volatile fatty acids in the anaerobic treatment system (Visser et al, 1993;Fabián & Gordon, 1999;Poh & Chong, 2009). In a study using synthetic wastewater in the thermophilic temperature, Visser et al found that at the pH of above 8.0, the methanogenesis was strongly inhibited and the value recorded for acetotrophic methanogenic test was zero (Visser et al, 1993). When investigating the role of pH in anaerobic degradation test, Fabián and Gordon, found out that the acidification led to the low performance of the anaerobic degradation, however the biodegradation was significantly increased once the waste was saturated with water and the pH was adjusted to above 6.5 (Fabián & Gordon, 1999).…”

Biogas Production from Anaerobic Treatment of Agro-Industrial Wastewater

“…In a study using synthetic wastewater in the thermophilic temperature, was found that at the pH of above 8.0, the methanogenesis was strongly inhibited and the value recorded for acetotrophic methanogenic test was zero (Visser et al, 1993). When investigating the role of pH in anaerobic degradation test; Fabián and Gordon (1999), found out that the acidification led to the low performance of the anaerobic degradation, however the biodegradation was significantly increased once the wastewater when the pH was adjusted to above 6.5.…”

Challenges of a feasible route towards sustainability in environmental protection

“…rather than attempting to take all possible benefits from it, which would be much more worthwhile. Since the late eighties numerous useful applications have already been discovered and implemented [89][90][91][92], under both mesophilic [93][94][95][96][97] and thermophilic conditions [58,[98][99][100][101]. In several of these studies, issues such as immobilization, substrate competition between SuRed-organisms and methanogens, and exposure to high salt concentrations have been addressed.…”