Recebido em 16/6/09; aceito em 18/12/09; publicado na web em 8/4/10 TREATMENT OF TEXTILE DYEING BATHS BY PHOTO-FENTON PROCESSES AND EVALUATION OF THE REUSE POTENTIALITY. In this work the treatment of textile dyeing baths by a sequential reductive-oxidative process was evaluated, aiming its utilization in new dyeing process. The results demonstrated that reactive dyes can be easily degraded by reductive processes mediated by zero-valent iron, a fact that induces decolorizations of about 80%. Sequential photo-Fenton processes permit almost total removal of the residual color with elimination of 90% of the COD content. The reuse of treated residues permits the achievement of materials that attend practically all textile specifications, with exception of the color difference parameter (DE), which is unsatisfactory toward the importation standards, but adequate for the national market.Keywords: dyeing; photo-Fenton; reuse. INTRODUÇÃONas últimas décadas, o fenômeno de contaminação ambiental alcançou proporções globais, afetando o delicado balanço de muitos sistemas ecológicos. Dentro deste contexto, deve ser dado especial destaque à sistemática contaminação das águas naturais, compartimentos que historicamente têm servido de vertedouro para uma grande variedade de resíduos domésticos e industriais.Em função das pessimistas projeções relacionadas com a disponibilidade de água, a legislação tem se tornado cada vez mais restritiva, evoluindo continuamente no estabelecimento de padrões específicos para o enquadramento de corpos de água, assim como de condições e padrões para o lançamento de efluentes (Resoluções CONAMA 357/2005 e 396/2008.No contexto industrial, a incorporação de práticas que permitam o reuso da água se torna cada vez mais urgente, não apenas para satisfazer as imposições da legislação, mas também para diminuir o seu consumo e reduzir os custos de produção.1,2 Esta necessidade se mostra especialmente importante na área de beneficiamento têxtil, na qual o consumo médio de água costuma alcançar valores da ordem de 160 m 3 por tonelada de fibra processada, 3 principalmente em função de operações de branqueamento, mercerização, tingimento e lavagem. 4 Os efluentes líquidos produzidos pela atividade têxtil se caracterizam por apresentar elevada carga orgânica, alta concentração de sais e forte coloração, esta última característica associada à presença de corantes residuais. Em geral, estima-se que 15 a 50% da carga de corantes pode ser perdida nas etapas de tingimento e lavagem, 5,6 o que torna evidente a necessidade de sistemas adequados de tratamento. Infelizmente, uma importante parcela destes corantes se mostra recalcitrante frente a processos biológicos convencionais, mesmo utilizando-se rotinas anaeróbias-aeróbias sequenciais. 7Em função das deficiências apresentadas pelos sistemas convencionais de tratamento, usualmente representados por processos biológicos e de coagulação química, 8 novas alternativas de tratamento têm sido regularmente propostas. Dentro do contexto do reuso dos efluentes têxteis é p...

The treatment and final destination of solid residues have turn out to be processes of great importance in the environmental and social policies. The segregation of residues and the selective collect enable the adequate destination of these residues, allowing the transformation of the recycable residues in raw material for the industry and the organic residues in compost to be used in agriculture and gardening. It is possible to participate in the Environmental preservation decreasing considerably the quantity of the organic residues sent to sanitary landfills, through the processes of compound and vermin compound, increasing useful life of these very residues and improving the quality of soil where such compound is utilized. Based on the exposed, this project realized the environmental awareness of the community of the Victor Konder District, through the setting of the compounders and vermin compounders in pilot scales at FURB, and applying questionnaires to 795 people at the Technical School Vale do Itajai and at the National Industrial Service, in high school. The orientation of the benefits proportioned by the process of segregation of solid residues and its treatment enable to relate the theoretical knowledge with activities of day-today , rethinking attitudes to understand the Environment.

Only the results of the physics-chemical analysis isolated do not show the environmental impact caused by the pollutants demonstrated through the effects on the ecosystem. Through the tests of toxcity the potential toxical of the chemical substances are put against the system of self protection of test-organisms, that react to the global effect of the substances present in the environment, indicating the effects of these, releasing information about the quality of the environment and about the existing impact. The control of the bathes in anatomic tanks as a whole can be made through the tests of toxicity, in which the aquatic organisms are exposed to various concentrations of this effluent. The application of the tests of toxicity in the environmental analysis is enough comprising and its importance increases with the accomplishment of the monitorings. About 4,5 m³ per year of effluents containing formaldehyde need the evaluation before the final discard. The exposure to the formaldehyde of the students and workers is conditioned to the level of concentration which is nowadays 10%. It has caused health problems and is under suspect of being carcinogenic. The formaldehyde also has effects in the environment, its flowing through the sewer system can cause fire, besides it is corrosive. The knowledge of the toxicity of the effluent was obtained, through the methods standarized as the test with Dapnia similis (aquatic organism) and Vibrio fischeri (bacterium) because of the quickness of the results. To avoid the toxical effect it is necessary a factor of dilution of the bathes between 1000 to 6400, for aquatic organism and bacterium respectively.