Alternativas para o aproveitamento de resíduo da indústria de pescado como ecomaterial adsorvente de corante tipo direto, obtenção de material nitrogenado, hidroxiapatita e material cer mico de hidroxiapatita

Abstract

Synthetic dyes are one of the most common pollutants and often found in the textile industry. The effluent containing dyes to water bodies is extremely important from an environmental perspective, since even at low concentrations the dyes can be highly toxic to aquatic systems. The high toxicity is a major problem of wastewater containing dyes. This study examined how ecomaterial of fish scales and their hydroyapatites as adsorbent direct dye. Natural materials were obtained in the laboratory and characterized by FTIR, TG and SEM to information on their structural and morphological characteristics is obtained. Column adsorption experiments were performed to investigate the adsorption of the dyes. Concentrations were evaluated in a UV/Vis spectrophotometer. The hydroyapatites have higher adsorption capacity that scales and that obtained by the method of obtaining nitrogen biopolymer showed the best results. Nitrogen is an important element for all organisms and to obtain nitrogen biopolymer fish scale using sonication and basic solution, the method comprising: washing, drying and grinding the fish scale by adding NaOH solution 51% scale fish, and then sonicated at 60oC; centrifugation and removal of solid solution for subsequent neutralization with 5% CH3COOH for 8 hours. The solid is filtered and it is added to a solution of NH4OH until precipitation of the material, subsequently neutralized and dried at 60oC. After filtering nitrogenous material, the inorganic fraction retained on the filter is washed until neutrality and calcined at 800oC for 4 hours allowing the extraction of hydroxyapatite. Biopolymers obtained from fish scale had a mean 80% degree of deacetylation measured by FTIR and NMR technique and yield ranging from 11 to 40.7%. The obtained ceramic materials by sol-gel method exhibited a degree of low to moderate adsorptivity, which is related to the amount of hydroxyapatite present in the material. All methodologies aired this work have real possibilities of evaluating an industrial residue low cost, but it dropped and deposited in the environment might cause serious problems to the environment in the medium and long term.