Evaporation and air-stripping to assess and reduce ethanolamines toxicity in oily wastewater.
Toxicity from industrial oily wastewater remains a problem even after conventional activated sludge treatment process, because of the persistence of some toxicant compounds. This work verified the removal efficiency of organic and inorganic pollutants and the effects of evaporation and air-stripping techniques on oily wastewater toxicity reduction. In a lab-scale plant, a vacuum evaporation procedure at three different temperatures and an air-stripping stage were tested on oily wastewater. Toxicity reduction/removal was observed at each treatment step via Microtox bioassay. A case study monitoring real scale evaporation was also done in a full-size wastewater treatment plant (WWTP). To implement part of a general project of toxicity reduction evaluation, additional investigations took into account the monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) role in toxicity definition after the evaporation phase, both as pure substances and mixtures. Only MEA and TEA appeared to contribute towards effluent toxicity.
Libralato
G
G
Department of Environmental Sciences, University of Venice, Campo della Celestia 2737/b, I-30122 Venice, Italy. giovanni.libralato@unive.it <giovanni.libralato@unive.it>
Ghirardini
A Volpi
AV
Avezzù
F
F
D000388:Air; D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D019856:Ethanolamine / Q000737:chemistry / Q000633:toxicity*; D004983:Ethanolamines / Q000737:chemistry / Q000633:toxicity*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D049449:Luminescence; D009821:Oils; D014618:Vacuum; D014835:Volatilization; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
D004983:Ethanolamines; D007220:Industrial Waste; D009821:Oils; D014874:Water Pollutants, Chemical; D019856:Ethanolamine; C009546:triethanolamine; C020283:diethanolamine