Enhanced volatile fatty acids accumulation in anaerobic digestion through arresting methanogenesis by using hydrogen peroxide

Abstract

Volatile fatty acids (VFAs) can be accumulated as a final product of anaerobic digestion via arresting methanogenesis. Herein, hydrogen peroxide (H2O2) was studied to inhibit methanogenesis for enhancing VFA accumulation with glucose as a substrate. The addition of 0.06 wt.% H2O2 significantly reduced methane production and led to a VFAs concentration of 1233.1 ± 55.9 mg L−1, much higher than 429.3 ± 5.6 mg L−1 in the control that did not have H2O2 addition. The dominated VFAs with H2O2 were acetic acid and propionic acid. A low H2O2 dosage of 0.03 wt.% produced 466.3 ± 3.9 mg L−1 more VFAs than that of O2 addition at the similar (theoretical) dosage, but when the dosage was relatively higher, the VFA accumulation with O2 addition became more than that with H2O2 addition, likely because of stronger oxidation of VFAs by the overly added H2O2. A hypothetical mechanism for H2O2 inhibition suggests that at a low H2O2 concentration the inhibition is mainly toward methanogenesis to limit their consumption of VFAs and a high H2O2 concentration starts to inhibit hydrolysis and acidogenesis and/or oxidize VFAs. Those results encourage further exploration of H2O2‐based arresting methanogenesis for VFAs production.

Coupled Biogas and Fiber Production from Agricultural Residues and Energy Crops with Steam Explosion Treatment

“…This observation is consistent with the finding that these substrates also had the highest SUM-VFA concentrations (Table 4). Despite the possibility of inhibition due to the high SUM-VFA concentration, it was not observed during the experiments because the inoculum used had a high buffer capacity [51][52][53][54][55].…”

Integrating Torrefaction of Pulp Industry Sludge with Anaerobic Digestion to Produce Biomethane and Volatile Fatty Acids: An Example of Industrial Symbiosis for Circular Bioeconomy

“…Hydrothermally treated thickened waste-activated sludge 1.53 [38] Glucose (methanogenesis inhibition using H 2 O 2 ) 1.23 [39] Food waste (methanogenesis inhibition using 2-bromoethanesulfonate) 0.8 [40] Pretreated corn stover (methanogenesis inhibition using 2-bromoethanesulfonate) 2.19 [41] Pulp sludge torrefaction condensate (methanogenesis inhibition using 2-bromoethanesulfonate) 1.1-4.78 This study…”

Influence of Abiotic Factors on Coir Retting Process

“…Evaluations of sludge extent of digestion can be made from its volatile solids content and its ability to dewater [19]. Studies also reported that inoculum pretreatment of sludge can regulate the volatile fatty acid accumulation [20]. Anaerobic biodegradation is a complex process involving many microbial steps that are conducted by different groups of bacteria, and the toxicity that occurs during anaerobic treatments typically occurs as a result of the incubation of methanogenic/acetogenic bacteria.…”