Evaluation of physical-chemical performance of an UASB reactor in removing pollutants of pig wastewater

Abstract

Attention has been given by governmental agencies concerning the swine production in confined areas, due to the pollution potential and problems related to epidemiology. Thus, anaerobic treatment system, similar to the one applied in this research, has became very important and raised interest for large scale production and field application. The purpose of this research was to evaluate the UASB reactor behavior considering a hydraulic retention time (HRT) of 9.7 hours, the hydraulic loading rate (HLR) of 2.5 m3 m-3 d-1, Organic loading rate (OLR) of 1.77 kg m3 m-3 d-1 and the average biogas production of 437.08 L d-1. It was found in this work, that the alkalinity in the affluent and effluent were 1,383 mg L-1 and 1,442 mg L-1, respectively. The Ripley alkalinity in the affluent and effluent presented a relation of IA/PA of 1,5 e 1,7, respectively. The CODtotal concentration in the affluent and effluent was 2,705 mg L-1 and 1,849 mg L-1, respectively. The BOD5 concentration in the affluent and effluent was 707 mg L-1 and 317 mg L-1, respectively. The total phosphorus concentration was 1.07 mg L-1 and 1.11 mg L-1 and the concentration of total Kjeldahl nitrogen was 69 mg L-1 and 63 mg L-1, respectively. The CODtotal/BOD5 relation was 0.41 and the efficiency of total, fix and volatile solids removal was 40%, 28%, 48%, respectively. The treatment system presented a good performance and therefore the operational parameters applied could be also useful for large scale systems.