Ozonation Impact on Degradation and Biotoxicity ofNon-ionic Surfactants

摘要

The aqueous solutions of selected non-ionic surfactants with thernfollowing trade names: Triton (I-octylphenolethoxylates), Tergitolrn(2,6,8-trimethyl-4-nonanoloxethylates), Symperonic (n-nonylphenoloxethylates)rnand Brij (fatty alcohol ethoxylates) were investigated inrnthis study. Using the bioluminescent bacteria Vibrio fischeri thernbiotoxicity of the surfactants solutions were determined. An attemptrnwas made to relate biodegradability of nonionic surfactant solutionsrnmeasured by the BOD5/COD ratio to their ecotoxicity. The ozonationrnprocess was carried out in a 1.5 dm3 stirred cell reactor equipped withrnozone detectors. The following parameters were analyzed: pH, COD,rnBOD5, DOC, TC, polarography as well as UV spectrum. The positiverneffect of ozonation, represented by decay of UV absorption, COD andrnTOC decrease was visible in almost complete destruction of therndetergents, with exception of Triton X-705. The most striking resultsrnwere obtained in biotoxicity test for ozonated solutions of the non-ionicrnsurfactants - an increase of bacterial growth inhibition. The obtainedrnresults were discussed taking into account the literature and our ownrndata on mechanisms of ozonation and biodegradation of similarrnchemical structures.