Characterization of the olfactory impact around a wastewater treatment plant: optimization and validation of a hydrogen sulfide determination procedure based on passive diffusion sampling.
A monitoring program based on an indirect method was conducted to assess the approximation of the olfactory impact in several wastewater treatment plants (in the present work, only one is shown). The method uses H2S passive sampling using Palmes-type diffusion tubes impregnated with silver nitrate and fluorometric analysis employing fluorescein mercuric acetate. The analytical procedure was validated in the exposure chamber. Exposure periods ofat least 4 days are recommended. The quantification limit of the procedure is 0.61 ppb for a 5-day sampling, which allows the H2S immission (ground concentration) level to be measured within its low odor threshold, from 0.5 to 300 ppb. Experimental results suggest an exposure time greater than 4 days, while recovery efficiency of the procedure, 93.0+/-1.8%, seems not to depend on the amount of H2S collected by the samplers within their application range. The repeatability, expressed as relative standard deviation, is lower than 7%, which is within the limits normally accepted for this type of sampler. Statistical comparison showed that this procedure and the reference method provide analogous accuracy. The proposed procedure was applied in two experimental campaigns, one intensive and the other extensive, and concentrations within the H2S low odor threshold were quantified at each sampling point. From these results, it can be concluded that the procedure shows good potential for monitoring the olfactory impact around facilities where H2S emissions are dominant.
Entidad Pública de Saneamiento de Aguas Residuales de la Comunidad Valenciana (EPSAR), Valencia, Spain.
Fernando Llavador
FL
Colomer
Héctor
H
Espinós-Morató
Enrique Mantilla
EM
Iglesias
Tatiana Gómez
TG
Pérez
Andreu
A
Campos-Candel
Caterina Coll
CC
Lozano
D000393:Air Pollutants / Q000737:chemistry*; D004058:Diffusion; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D006862:Hydrogen Sulfide / Q000737:chemistry*; D009812:Odorants; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000592:standards*
D000393:Air Pollutants; D006862:Hydrogen Sulfide