title: Glutaraldehyde degradation in hospital wastewater by photoozonation.
abstract: In this paper, we assessed aqueous solutions of glutaraldehyde (GA), a chemical used for the disinfection of hospital materials, using advanced oxidative processes, O3, and UV, and the combination of the latter two. Assays with different ozone concentrations at distinct pH levels were conducted to determine the best treatment process. GA concentrations before and after each treatment were measured by spectrophotometry. The best treatment was that which combined O3 and UV, yielding a degradation of 72.0-75.0% in relation to the initial concentration with pH between 4 and 9. Kinetics demonstrated that GA degradation is not dependent on pH, as there was a first-order reaction with a rate constant of k = 0.0180 min(-1) for initial pH 9 and of k = 0.0179 min(-1) for initial pH 7, that is, the values are virtually the same. Secondary wastewater samples were also analysed using the septic tank/filter system of a regional hospital in Vale do Rio Pardo, state of Rio Grande do Sul, southern Brazil. In this case, the characteristics of the wastewater were described and, after treatment, a GA degradation rate of 23.3% was noted, with reductions of 75% for chemical oxygen demand, 81% for biochemical oxygen demand, 68% for turbidity, 70% for surfactants and total disinfection in terms of thermotolerant coliforms.
authors: Department of Chemistry and Physics, Master's Program in Environmental Technology, Universidade de Santa Cruz do Sul, Brazil. lourdes@unisc.br
authors: Lourdes Teresinha
authors: LT
authors: Kist
authors: Master's Program in Environmental Technology, Universidade de Santa Cruz do Sul, Brazil.
authors: Ellen Caroline
authors: EC
authors: Rosa
authors: Department of Chemistry and Physics, Master's Program in Environmental Technology, Universidade de Santa Cruz do Sul, Brazil.
authors: Enio Leandro
authors: EL
authors: Machado
authors: Department of Mathematics, Master's Program in Environmental Technology, Universidade de Santa Cruz do Sul, Brazil.
authors: Maria Emilia
authors: ME
authors: Camargo
authors: Department of Inorganic Chemistry, Universidade Federal do Rio Grande do Sul, Brazil.
authors: Celso Camilo
authors: CC
authors: Moro
mesh_terms: D005976:Glutaral / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D010782:Photolysis; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D005976:Glutaral; D010126:Ozone; D062065:Wastewater; D014874:Water Pollutants, Chemical