The behaviour of an anaerobic baffled reactor (ABR) as the first stage in the biological treatment of hog farming effluents

Abstract

This present paper reports a study of the efficiency of an anaerobic Baffled Reactor (ABR) composed of three chambers working as the first stage of a biological treatment system for swine wastewater, over a period of 116 days. The average value of the volumetric organic loading rate (VOLR) was 17.8 kgCODtotal m-3 d-1, the biological organic loading rates (BOLR) based on total and filtered COD influents of 14381 mg L-1 and 3610 mg L-1, respectively, were: 1.3 kgCODtotal kgTVS d-1 and 0.98 kgCODfiltered kgTVS d-1, respectively, and the hydraulic loading rate (HLR) was about 1.4 m3 m-3 d-1. The average removal efficiency for total COD was 80% at a hydraulic retention time (HRT) of about 18 hours. The average alkalinity in the effluent was 3801 mgCaCO3 L-1. The average removal efficiencies for oil and grease and total soluble solids were 41% and 78%, respectively. The sludge granulation and biogas production in the ABR were quite different between the first and third compartment, showing a distinct microbial consortium in each chamber. Through this research it was confirmed that this type of reactor can be employed as the first stage in a system treating swine wastewater.