Physical-chemical characterization and determination of aerobic kinetic coefficients for the removal of organic matter from agro-industrial wastewater

ABSTRACT The aim of the present work was to perform a physicochemical characterization of different agroindustrial wastewaters (AIW), to apply first and second order kinetic models to verify which one best describes the progression of the biochemical oxygen demand (BOD) and to determine the aerobic kinetics coefficients of organic matter removal from AIW. The BOD progression assay was performed from the incubation of AIW in a respirometric system (Oxitop®). The first and second order kinetic models were evaluated by mean square error (RMSE), normalized mean square error (NRMSE), and Akaike Information Criterion (AIC). The aerobic biodegradation kinetics of the AIW evaluated was better fitted to the first order model in terms of total and soluble BOD. In the total BOD progression, the highest coefficient of first-order deoxygenation (k ') was that of slaughterhouse wastewater (SW; 0.56 d-1) and the lowest was that of swine wastewater (SSW; 0.16 d-1). The deoxygenation coefficients determined in the present work were representative, and can be used for the simulation of degradation processes of organic matter under aerobic conditions.