Sistema alternativo de tratamento de águas residuárias destinadas ao reúso agrícola.

Abstract

Population growth, linked to the advance of industrialization in cities, caused numerous environmental problems, such as the production of wastewater. In urban and rural areas of the micro-regions of the states, this problem presents an even more worrying scenario due to the lack of government incentives regarding treatment technologies for these waters. This research, developed in the scope of the Reference Laboratory in Desalination of the Federal University of Campina Grande, aims to study and evaluate the performance of a pilot wastewater treatment system for agricultural purposes, composed of three tubular type reactors, with polystyrene bed. The evaluation of the system was carried out as a function of the reactors arrangements, in series and/or parallel, using different polystyrene particle sizes and flow rates. From the experimental results, it was observed that the 2.0 mm polystyrene spheres were the ones that most changed their weight and diameter, however, after drying, they returned to their initial characteristics. Comparing the efficiency of the two studied configurations, it was observed that the system with series reactors, and a 2.0 mm diameter polystyrene bed, presented the highest removal rate of chemical oxygen demand, color, turbidity, E coli, total phosphorus, and nitrification, when operated at 0.5L/min. In terms of system maintenance, backwashing the filter media was a fundamental step in recovering the production and quality of the permeate. The results of the physical, chemical and microbiological analyzes of the water samples, after the process with the reactor system in series at 0.5 L/min, were within the standards established for Classes 2 and 3 of CONAMA, thus enabling its use in irrigation.