Acid Fermentation Process Combined with Post Denitrification for the Treatment of Primary Sludge and Wastewater with High Strength Nitrate

Abstract

Abstract:In this study, an anaerobic baffled reactor (ABR), combined with a post denitrification process, was applied to treat primary sludge from a municipal wastewater treatment plant and wastewater with a high concentration of nitrate. The production of volatile fatty acids (VFAs) was maximized with a short hydraulic retention time in the acid fermentation of the ABR process, and then the produced VFAs were supplied as an external carbon source for the post denitrification process. The laboratory scale experiment was operated for 160 days to evaluate the VFAs' production rate, sludge reduction in the ABR type-acid fermentation process, and the specific denitrification rate of the post denitrification process. As results, the overall removal rate of total chemical oxygen demand (TCOD), total suspended solids (TSS), and total nitrogen (TN) were found to be 97%, 92%, 73%, respectively, when considering the influent into ABR type-acid fermentation and effluent from post denitrification. We observed the specific VFAs production rate of 0.074 gVFAs/gVSS/day for the ABR type-acid fermentation, and an average specific denitrification rate of 0.166 gNO 3´-N/gVSS/day for the post denitrification. Consequently, we observed that a high production of VFAs from a primary sludge, using application of the ABR type acid fermentation process and the produced VFAs were then successfully utilized as an external carbon source for the post denitrification process, with a high removal rate of nitrogen.

Valorization of volatile fatty acids from the dark fermentation waste Streams-A promising pathway for a biorefinery concept

“…Besides the bioconversion of acidogenic-derived VFAs into the aforementioned products, these fermentative by-products have also been used in other biotechnological methods such as denitrification process [131], removal of toxins in wastewaters [132], and production of alcohols such as ethanol [133] and butanol [134,135]. Nevertheless, there is also a paucity of such studies in the literature, which implies that more work is still needed in the bioconversion of these effluents to other value-added products.…”

Microbial Resources, Fermentation and Reduction of Negative Externalities in Food Systems: Patterns toward Sustainability and Resilience

“…Some studies proposed pathways towards enhanced nutrient bioavailability [10,[58][59][60] and improved human health/well-being [61][62][63][64] (including microbiome therapies [63][64][65][66]), advances of interest to contrast the adverse effects of some negative externalities. Furthermore, the design of several works looking at reducing resource dissipation, saving energy [52,69], valorising foods by-products [52,70,71], foods wastes [72][73][74], and wastewater [75][76][77]. Finally, some strategies can preserve microbial diversity associated with food fermentation [78][79][80].…”

Effects of FNA pretreatment on municipal solid waste acidifaction for volatile fatty acid production

“…Anaerobic digestion can be commonly applied to high-load wastewater treatment because anaerobic treatment has the following benefits compared with aerobic treatment: production of excess sludge is kept at a minimum with low minimum operation and maintenance requirements, and low energy demand without aeration and production of biogas with a renewable energy content, which can be used as a fuel (Kurniawan, Kwon, Shin, Hur, & Cho, 2016). The states of anaerobic digestion process are shown in Figure 4.…”