RESUMO A indústria têxtil utiliza um grande volume de água, o que torna necessário encontrar opções mais sustentáveis para o seu uso, como a reutilização em novos tingimentos. O uso de um resíduo industrial sólido, como adsorvente, poderá ser uma alternativa para tratar o efluente têxtil. Este estudo teve como objetivo testar a viabilidade do reuso de solução de corante disperso, tratada com resíduo da clarificação de óleo vegetal como adsorvente alternativo, no tingimento de malha poliéster/algodão (PES/CO 50/50). Utilizou-se dois tipos de pré-tratamento no adsorvente, natural (RC) seco a 70°C por 24h e calcinado (RCc) a 600°C por 2h 30min. Realizou-se o tingimento na cor clara com a solução tratada nas concentrações 100%, 75% e 50% (v/v), o padrão foi tinto com água da indústria têxtil. Para análise da eficiência do tratamento utilizou-se espectrofotometria UV-Vis, e a avaliação dos tecidos tintos pelos parâmetros tintoriais: esgotamento (%) por espectrofotometria UV-Vis; K/S, força relativa (FR%) e DE por espectrofotometria de remissão, como também ensaios de solidez a fricção e a lavagem. A eficiência do tratamento foi de 91,26% para o resíduo RC, e 95,38% para o RCc. Os valores de esgotamento variaram entre 80% e 92% para PES e 70% e 85% para CO. O DE variou entre 0,22 e 1,2, sendo que a maioria dos valores estão dentro da faixa aceita pela indústria (DE ≤1,0). Não houve grande variação para os valores de K/S e a FR (%), tendo a maior variação de 0,09 unidades para o K/S e 7,2% para a FR (%). Os testes de solidez apresentaram notas entre 4/5 e 5 nas escalas de cinza, indicando que não há a migração do corante. A proposta do tratamento e reutilização da solução em novos tingimentos mostrou-se uma alternativa viável, quando comparado ao tingimento padrão.

ABSTRACT The textile industry uses a large volume of water, which makes it necessary to find more sustainable options for its use, such as reuse in new dyeing. The use of a solid industrial waste as an adsorbent may be an alternative to treat the textile effluent. The objective of this study was to test the viability of the reuse of dispersed dye solution, treated with residue of the clarification of vegetable oil as an alternative adsorbent, in polyester/cotton (PES/CO 50/50) knitted fabrics dyeing. Two types of pre-treatment were used in the adsorbent, natural (RC) dried at 70°C for 24h and calcined (RCc) at 600°C for 2h30min. Dyeing was performed with the solution treated at 100%, 75% and 50% (v/v) concentrations and in light colors, the pattern was dyed with water from the textile industry. UV-Vis spectrophotometry was used to evaluate the efficiency of the treatment and the evaluation of the red tissues by dyeing parameters: exhaustion (%) by UV-Vis spectrophotometry; K/S, relative strength (SR%) and DE by remission spectrophotometry, as well as color fastness to washing and friction . The treatment efficiency was 91,26% for RC residue, and 95,38% for RCc. Values ranged from 80% to 92% for PES and 70% to 85% for CO. The DE ranged from 0,22 to 1,2, with most values falling into the range accepted by industry (DE≤1,0). There was no great variation for K/S and SR (%) values, with the greatest variation of 0,09 units for K/S and 7,2% for SR (%). The color fastness showed grades between 4/5 and 5 on the gray scales, indicating that there is no migration of the dye. The proposal of treatment and reuse of the solution in new dyeing showed as a viable alternative when compared

RESUMO A inovação dos processos de beneficiamento de materiais têxteis é cada vez mais importante para possibilitar a redução no consumo de água e nos tempos de processo na indústria têxtil. O consumo de fibras têxteis no Brasil em 2014 foi de 13,3 kg por habitante, e para beneficiar estes tecidos são utilizados em média 80 litros de água para cada quilograma de substrato tratado. Este estudo visou aprimorar o processo de pré-alvejamento para tecidos têxteis utilizando o ozônio com o objetivo de reduzir o consumo de água, de aditivos químicos, de tempo e bem como de energia. O potencial de redução do ozônio (2,07 V) é maior que o potencial de redução do peróxido de hidrogênio (1,77 V), o que faz com que o ozônio seja um excelente agente oxidante. A avaliação dos resultados de resistência física (estouro e tração), propriedades tintoriais (K/S, FC % e DE) e do grau de branco do tecido, indicam que o processo de pré-alvejamento com ozônio a frio é promissor na indústria têxtil, pois além de eliminar a utilização de peróxido de hidrogênio e hidróxido de sódio, reduz o tempo de processo em 60% e diminui o consumo de água em 50%.

ABSTRACT The innovation of the processes of the textile materials is becoming more and more important to reduce the amount of water and the use of machinery time in the textile industry. The consumption of textile fibers in Brazil in 2014 was 13,3 kilograms per capita and to produce these fabrics with 80 liters of water on average are used to each kilo of treated substract. This study aims to improve the pre-bleaching process for textile fabrics using the ozone with the objective to reduce the consumption of water, chemical products, time as well as energy. The potential for reducing ozone (2.07 V) is greater than the reduction potential of hydrogen peroxide (1.77 V), which makes the ozone is an excellent oxidising agent. The evaluation of results in resistance (strength and traction), dyeing properties (K/S, FC % and DE) and the whiteness degree of pre-bleached fabrics using cold ozone indicates that this is a promising process for the textile industry, since it not only eliminates the use of hydrogen peroxide and sodium hydroxide but also allows eliminating the process in at least 60% also reducing water consumption in 50%.

The high calorific value of rice husks has elevated its reuse as an energy source; however, the burning of these shells generates a waste ash from rice husk ash (RHA), which makes its disposal a concern. Despite advances, biodegradable polymers are not yet able to compete with those of traditional thermoplastics, which have lower production cost and higher performance. Based on this background, this paper studies the feasibility of reuse of RHA as filler in polymer matrices replacing the conventional filler. This study consists of applying different percentages of RHA in the formulation of polyhydroxybutyrate composite (PHB) and the use of talc (TA) for comparison purposes as conventional filler. The composites used in this assay were obtained by twin-screw extrusion and injection molding of the polymer plus the fillers under study. Physicochemical and biodegradability properties of the composites were evaluated. The composite PHB/RHA was superior in the biodegradability tests and the properties remain practically unchanged in the presence of the filler. Thus, composites with RHA are promising because they take an abundant residue combined with degradation capacity of the polymer, therefore reducing cost and the environmental impact.

On a laboratory scale effluents were produced from bichromic dyeing of acrylic fabrics with the basic dyes Blue Astrazon FGGL 300% and Yellow Gold Astrazon GL 200%. The residual dyeing baths were subjected to a photoelectrochemical treatment and reused in a second dyeing process. In the reutilization study, dyeings with treated effluent were compared with standard dyeings with distilled water. The results of dyeings using 100% of treated effluent were unsatisfactory, but the substitution of 10 to 30% of the treated effluent by distilled water resulted in reduced and more acceptable values for difference in colour intensity (ΔE) between 1.86 and 0.3.

The discussion based on surfactant cleaning action is commonly used in chemistry classrooms for the comprehension of theoretical concepts related to surface tension and micelle formation. The experimental quantification of surface tension of aqueous solutions of surfactants provides the practical instruments for this discussion. The present paper describes a simplification on the common apparatus employed for the drop-weight method, making the determination of surface tension accessible to any chemistry lab. The surface tension of various liquids and the critical micelle concentration, CMC, of three commercial surfactants were measured with this modified method, and proved to be consistent with literature values.