DETERMINATION OF ATMOSPHERIC AMMONIA CONCENTRATIONS AT A WASTEWATER TREATMENT PLANT USING A LABORATORY-BUILT PASSIVE SAMPLER

Abstract

Ammonia (NH3) concentrations were measured at nine locations using passive samplers where the malodor is intense in the central wastewater treatment plant (WWTP) in Konya, Turkey. A badge-type passive sampler suitable for both indoor and outdoor use was developed in the study to sample the NH3 gas released. The detection limit for a two-week exposure period is approximately 0.34 mu g/m(3). Validation of the passive samplers' performance was carried out by means of an experimental setup located in a laboratory environment. The field performance of the passive samplers was evaluated by analyzing samples simultaneously collected from nine different locations in the Konya WWTP during summer and fall periods. Higher NH3 concentrations were measured in the samples collected in summer than in those collected in fall. The 15-day average NH3 concentrations determined in the air samples collected from the plant inlet, pump unit 1, pump unit 2, bar screen, grit chamber, primary setting, and the sludge thickener (two locations) were determined to vary in the range of 21.58-61.70 mu g/m(3) for the samples collected in summer and in the range of 11.10-63.0 mu g/m(3) for those collected in fall. The highest concentrations were found in the bar screen, prior to the induction of chemical biological treatment.