Influence of acidogenic fermented fish by-products with rice bran for sludge reduction and biogas recovery in anaerobic co-digestion

Abstract

The purpose of this study was to investigate the effects of acidogenic fermentation broth with rice bran (RFFB), tap water (TFFB), or raw fishery by-products (FBs) on sludge reduction and biogas production in an anaerobic co-digestion process. Acidogenic fermentation of FBs with rice bran was faster and produced more volatile fatty acids than that with tap water. Reduction efficiencies for chemical oxygen demand, volatile solids, and total solids were highest in RFFB. In the kinetic analysis, λ (d), which represents the duration of the lag phase, was shortest with RFFB (1.09 d) and highest in sewage sludge (8.86 d). As the loading amount of volatile solids and chemical oxygen demand increased, the amount of cumulative biogas also increased. Amount of produced methane and energy recovery were highest with RFFB (5.71 kWh). Anaerobic co-digestion of FFB and sewage sludge allowed reduced sludge and recovered energy using the discarded waste as an organic carbon source.

Aquaculture from inland fish cultivation to wastewater treatment: a review

“…The treatment was conducted at 35 °C, HRT of 30 days, and a mixing rate of 150 rpm, resulting in COD and total solids removal in the range of 30.4-83.8% and 25.3-77.9%, respectively. The methane production was in the range of 0.38-0.57 m 3 /kg VS (Choi 2021). In comparison with domestic and industrial sludge, methane production using AWW is low due to the lower amount of solid waste, especially if the waste is derived from traditional fish cultivation methods (Choudhury et al 2022).…”

Two step anaerobic co-digestion of sesame oil cake and sewage sludge for sludge reduction and biogas production

“…In recent years, research on the synergistic effects of increasing biogas production and reducing sludge through co-digestion with various co-feedstocks and sewage sludge is underway. Co-digestion is anaerobic digestion in which various co-feedstocks and sewage sludge are combined in a single anaerobic digester (Choi 2021). Codigestion is a viable option to increase methane yield and promote sludge reduction over anaerobic digestion with a single feedstock (Choi 2021;Jeong et al 2019).…”

“…Co-digestion is anaerobic digestion in which various co-feedstocks and sewage sludge are combined in a single anaerobic digester (Choi 2021). Codigestion is a viable option to increase methane yield and promote sludge reduction over anaerobic digestion with a single feedstock (Choi 2021;Jeong et al 2019). The utilization of a co-feedstock with different chemical compositions, particularly with regard to nutrients, can improve the process due to the positive synergistic effect established in the digestion medium and the supply of scarce nutrients (Jhr et al 2020).…”

“…According to a previous study, when the concentration of VFAs is above 4000 mg/L and the ratios of VFAs and alkalinity are above 0.8 in anaerobic co-digestion, the pH decreases and methane production is inhibited (Chanda et al 2012;Choi 2021). However, the ratio of VFAs/alkalinity was determined above 1.2 using food waste in an anaerobic co-digestion process (Jeong et al 2019;Karki et al 2021), but the pH and biogas production did not decrease.…”

“…digestion, it is important to maintain/manage operating factors such as pH, C/N ratio, temperature, and VFAs/alkalinity within an appropriate range (Chen and Brewer 2021;Wang et al 2018). In addition, when ammonia and heavy metals exceed a certain concentration, close attention is required because the proliferation and activity of anaerobic microorganisms is inhibited by the dissociation equilibrium and toxicity in the anaerobic digester(Choi 2021;Choi 2020a). The microorganisms in the anaerobic digester show different activities depending on the pH range, and since the dissociation equilibrium of inhibitors such as ammonia and…”