Characterization of an acidification and equalization tank (AET) operating as a primary treatment of swine liquid effluent.

摘要

This work evaluated the potential of the acidification equalization tank (AET) used as a primary treatment unit, treating the hog farming wastewater. The treatment system consisted of a degritter with a triangular-notch weir, for measuring the flow, a static sieve, and an acidification and equalization tank (AET), an anaerobic baffled reactor (ABR), an upflow anaerobic sludge blanket (UASB) reactor, a settling tank, a greenhouse for fertirrigation and two infiltration ponds. The AET had a net capacity of 8,000 liters, internally covered with asphalt blanket, worked based on surface loading rates application. The unit operated continuously, with its flow varying from 0.1 to 10 L s-1. To determine the efficiency, the following parameters were measured: pH; COD; BOD; volatile and fixed solids; settleable solids; total, intermediate and partial alkalinity and total acidity. The COD removal varied from 5 to 20%. The average pH was 7.3 and the total, intermediate and partial alkalinity in the effluent, were 1919, 846, 1197 mg L-1, respectively. The total acidity in the effluent was 34 mg L-1. The influent and effluent total BOD and oil & grease concentrations were 3436 and 3443 mg L-1, and 415 and 668 mg L-1, respectively. It was found that the AET worked properly concerning the acidification, equalization and sedimentation processes, confirming low cost of implementation and easy operation, when compared to other traditional decanters.Digital Object Identifier http://dx.doi.org/10.1590/S1516-89132013000300017