A kinetic study on carboxylic acids production using bovine slaughterhouse wastewater: a promising substrate for resource recovery in biotechnological processes

Abstract

Carboxylic acids (CA) are considered high added-value compounds, and their production from wastes has gained economic and environmental notoriety. However, the CA production and kinetic modeling using some agro-industrial wastewaters, such as bovine slaughterhouse wastewater (SHW), are not well reported in the literature. Therefore, the objective of this work was to evaluate the CA production potential using SHW as a substrate under acidogenic conditions and to apply mathematical models to estimate the kinetic parameters of particulate organic matter hydrolysis, soluble organic matter consumption, and CA production. Tests were carried out in quadruplicate batch reactors with a 250-mL reaction volume, with brewery sludge as inoculum and using chloroform (0.05%, v/v) for methanogenesis inhibition. The obtained yield was 0.55 g acids gCOD A −1 , corresponding to 0.76 gCOD gCOD A −1 . The production of caproic acid without the addition of electron donors was achieved. Mathematical models that describe exponential growth, such as the first-order exponential model, cone model, and Fitzhugh model, were the most suitable to describe the production kinetics of CA. Finally, SHW seems to be a promising substrate to be investigated in the carboxylic platform.

Study on Brazilian agribusiness wastewaters: composition, physical‑chemical characterization, volumetric production and resource recovery

“…In further research, Morais et al (2021) and Coelho et al (2020a) also evaluated the prospecting of CAs from SHWs and RG, respectively, using the same operational conditions as their previous studies with SWs and DWs. For SHWs, the authors reported the conversion of 76% of COD to CAs (yield of 0.55 g acids per g COD), while for RG a yield of 0.62 g acids per g COD was obtained, corresponding to 82% conversion of applied organic matter.…”