Effects of thermal pretreatment on acidification phase during two-phase batch anaerobic digestion of kitchen waste

Abstract

a b s t r a c tThe effect of thermal pretreatment (55e160 C) on the degradation characteristics of kitchen waste during anaerobic fermentation at medium temperature was investigated. The breakdown of both organics and inorganics and the enhancement of biogas production in batch tests caused by thermal pretreatment during subsequent anaerobic fermentation were examined. Considering the effect of the acidification products and ammonia nitrogen in the acidification phase on subsequent biogas production, the influencing factors and related characteristics of various fermentation types were investigated. The results indicate that thermal pretreatment cannot only promote the anaerobic degradability of KW and the biogas production from KW but can also reduce the retention time necessary for anaerobic acidification by five days. At 50e70 C and 140e160 C, the biogas production and organic removal rates of the subsequent anaerobic digestion process decreased slightly, whereas at 90 and 120 C, superior results were achieved during digestion.

Mass Loss Controlled Thermal Pretreatment System to Assess the Effects of Pretreatment Temperature on Organic Matter Solubilization and Methane Yield from Food Waste

“…The results are consistent with the reports of Li and Jin (2015), who obtained higher concentrations of acetic, propionic and n-butyric acid for thermally treated kitchen waste compared to untreated kitchen waste during the anaerobic fermentation process. The rapid decrease of acetic acid corresponded to the increased methane percentage in the produced biogas in all BMP tests (Figure 5), which reflected the dominant activities of acetoclastic methanogens during the BMP tests (Luo et al, 2011).…”

“…In contrast, the pattern of VFAs production and consumption during the BMP tests appeared similar regardless of a thermal pretreatment. The higher concentrations of VFAs in the initial days (days 1-5) were due to the faster hydrolysis and acidification of FW (Li and Jin, 2015). Nonetheless, the concentration of the VFAs did not inhibit the methanogenic activity, as evidenced by the increased methane concentration during these operational days (days 1-5).…”

“…With the worldwide economic development and population growth, food waste (FW) production is alarmingly increasing and imposes a great challenge in waste management for most countries Li and Jin, 2015). Today, anaerobic digestion (AD) is one of the most consolidated technologies for waste treatment and valorization, compared to other possible treatment routes (Ferreira et al, 2013;Wagner et al, 2014;Zhang et al, 2014).…”

“…Therefore, the kinetics of the AD process are improved, leading to a higher reactor efficiency (Bougrier et al, 2007;Wang et al, 2010;Zhou et al, 2013;Kondusamy and Kalamdhad, 2014;Li and Jin, 2015). Heating temperature and pretreatment time have been found as the key factors in determining the effectiveness of TP (Carrère et al, 2009;Rincón et al, 2013).…”

The Response of Biogas Production and Methanogenic Community to the Variation of Intermediate Vfas Produced During the Anaerobic Digestionof Food Waste

“…FW with great producing mount creates many challenges in terms of environmental protection and public health [3,4]. However, FW contains a large amount of volatile organic compounds mainly in terms of single sugars, starch and protein, which are nutrient-rich organic material to produce biogas and other energyrich organic compounds as end-products by anaerobic digestion (AD) [5].…”