Upflow Anaerobic Filter for Pet Food Wastewater Treatment

Abstract

Anaerobic biodigestion is a process that has been widely used to agroindustrial effluents treatment, where most of the organic matter is present in dissolved form and is easily biodegradable. In this work we used an upflow anaerobic biological filter to treat effluent from a company that processes byproducts from the meat industry to produce pet food. The substrate had Chemical Oxygen Demand (COD) values ranging from 738 to 1102 mg O2 L-1 and Total Kjeldahl Nitrogen (TKN) contents from 143 to 723 mg L-1. The filter was operated continually at room temperature, with organic loads from 0.077 to 1.083 kg COD m-3 d-1 and Hidraulic Retention Times (HRT) of 240, 168, 120, 72, 48, 24, and 21 hours. The best COD removal results were obtained under a 24-hour HRT, in which a COD of 154 mg O2 L-1 was obtained for the effluent. It can be concluded that, under the conditions employed, the anaerobic digestion process was effective for COD removal.