ODOR REMOVAL IN WASTEWATER TREATED BY ROOTS ZONE BED (WETLANDS)

Abstract

The wetland is a system that uses the roots plants (macrophyte) in the domestic wastewater treatment. The mechanisms (physical, chemical and biological ones) of organic matter stabilization of effluent and odorous compounds (commonly found in anaerobic biological degradation) involve soil, microorganisms and plants. This work uses olfactometry (technical of odors analysis) as tool in the evaluation of the odor remotion of sewage treated by Root Zone Sewage Treatment Station (RZSTS) in an rural community of Irati City (Brazil). For a better evaluation of the effectiveness of the odor remotion, the odors (rather and downstream treatment) has been evaluated in the three olfactometric categories (intensity, character and hedonic tone), according to European standards. The results had pointed that wastewater treated still presented perceivable levels of odor even after significant reduction in intensity (the reduction in the category “very strong” was 89,3% between the entrance and outlet wastewater of the macrophyes station). Moreover, “offensive” category was cited by the jury in the two effluent (entrance and outlet one, with 91% and 40% of answers, respectively); however, in this same question, the wastewater treated presented less aggressive and unpleasant odors. In a general way, the station proposed revealed efficiency in odorous compounds stabilization by anaerobic biological degradation.