Molecular Characterization And Ecotoxicological Evaluation of The Natural Dye Madder And Its Chlorinated Products

There has been increased interest in the use of natural dyes for textile coloration as alternatives to synthetic dyes, due to the general belief that natural dyes are more environmentally friendly. However, natural dyes have poor affinity for textiles, which can lead to high dye levels in the resultant wastewater. While chlorine treatment has proven to be effective for dye wastewater disinfection and decolorization, this process can also lead to the formation of more toxic degradation products for certain synthetic dyes. On the other hand, little information is available regarding the ecotoxicity of natural dyes and their chlorination products. To advance knowledge in this area, madder was selected due to its historical importance and wide application in the textile industry. Specifically, we sought to characterize the chlorine-induced degradation products of an aqueous madder solution and to assess their ecotoxicity. The main component of the present madder sample was Alizarin (89.8%). Chlorination led to complete decolorization, and 2-hydroxynaphthalene-1,4-dione and phthalic anhydride were identified as key degradation products. Chlorination of madder decreased toxicity to Daphnia similis (microcrustacean) 10-fold and removed the toxicity to Raphidocellis subcapitata (algae), when compared to the parent dye.

Avaliação ecotoxicológica de medicamentos tuberculostáticos: Concentrações Ambientais Estimadas e efeitos biológicos em Daphnia similis e Echinometra lucunter.

Com o passar do tempo, o crescimento da produção de produtos farmacêuticos vem aumentando gradativamente e consequentemente, os resíduos destes produtos de forma inadequada no ambiente aquático também. Neste contexto, destaca-se a escassez de estudos ecotoxicológicos sobre os medicamentos da classe dos tuberculostáticos no meio aquático. Sendo assim, o presente estudo teve como objetivo avaliar a presença dos fármacos tuberculostáticos utilizados como esquema padronizado pelo Ministério da Saúde para o tratamento de tuberculose (Rifampicina, Isoniazida, Pirazinamida e Etambutol) em águas superficiais do município de Cubatão (São Paulo, Brasil), através do cálculo da concentração ambiental estimada (CAE). Adicionalmente, foram avaliados os efeitos biológicos adversos nos organismos-testes Daphnia similis e Echinometra lucunter para os fármacos Isoniazida e Pirazinamida. As concentrações ambientais estimadas foram calculadas para os quatro fármacos tuberculostáticos de acordo com a diretriz da Agência Europeia de Medicamentos (EMEA) (CHMP, 2006). Após, foram realizados ensaios de toxicidade em D. similis e E. lucunter de acordo com as normas ABNT NBR 12713:2016 e ABNT NBR 15350:2012, respectivamente. Os resultados das CAE para todos os fármacos tuberculostáticos incluídos neste estudo apresentaram valores superiores ao limite considerado pela EMEA de 0,01 µg.L-1. Para o ensaio de toxicidade com D. similis, os fármacos Isoniazida e Pirazinamida apresentaram valores de CE50 respectivamente 69,97 mg.L-1 e 44,49 mg.L-1 sendo estes classificados como “nocivos” de acordo com a Diretiva da Comunidade Econômica Europeia (CEE) 93/67/CEE. Já para o ensaio de toxicidade com o organismo-teste Echinometra lucunter, os fármacos Isoniazida e Pirazinamida apresentaram valores de CI50 23,66 mg.L-1 e 17,21 mg.L-1, respectivamente, resultados que os também como “nocivos” de acordo com a Diretiva 93/67/CEE. Os resultados desta pesquisa poderão servir como subsídios a novas legislações e a criação de programas governamentais que buscam soluções promovendo redução e até mesmo a eliminação de fármacos no ambiente aquático.

Heterogeneous photodegradation of bisphenol A and ecotoxicological evaluation post treatment

Bisphenol A (BPA) is an emerging pollutant with endocrine disrupting properties that can be found at trace levels in various aqueous environments. Conventional water and wastewater treatments are not designed to efficiently remove these substances. Therefore, this work investigates the removal of BPA by an Advanced Oxidation Process (AOP), specifically heterogeneous photocatalysis using TiO2. The influences of the TiO2 concentration (1.0–10.0 mg L-1), pH (5.3 and 8.5) and effects matrix composition were studied for the removal of BPA at a concentration of 0.8 mg L-1. The results indicated that BPA was completely removed after 45 min of treatment using 7.5 and 10 mg L-1 of TiO2, under constant aeration and artificial UV irradiation, at the different pH values. The use of solar radiation as an UV source was also effective, removing BPA after 60 min of irradiation at pH without adjustment, as well as at pH 8.5. Ecotoxicological evaluation indicated that the post-treatment samples did not present acute effects towards Daphnia similis. Evaluation of chronic toxicity with Raphidocelis subcapitata showed that there was a reduction in the negative effect of BPA under the growth rate of algae biomass after 60 min of treatment, compared to the initial sample.

Evaluation of ecotoxicity of contaminated water for validation of phytoremediation time

Phytoremediation has been used as an alternative for removal of heavy metals in aquatic environments, but plant residence time and toxicity reduction need to be studied. Ecotoxicological bioassays and root anatomic studies were conducted in order to validate the phytoremediation of Echinochloa crus-galli L. at three different ages. The experiment was conducted using E. crus-galli seeds with processing factorial experimental design (2x3) and four replicates. Cadmium presence and absence (0.8 and 0 mg L-1) at three times (20, 30, and 45 days after germination). Cd levels were quantified by flame atomic absorption spectroscopy on both aerial parts and roots. A bioassay was performed testing both acute and chronic effects using microcrustacean Daphnia similis with the purpose of evaluating phytoremediation efficiency. Regardless of biomass, E. crus-galli L. can be used for 16 to 19 days for 45 days after germination (DAG), tolerating the phytotoxicity of this metal. The residual solution after phytoremediation had chronic effect on D. similis, indicating that the time taken was not sufficient to reduce the toxicity of the solution. Thus, ecotoxicological essays are important tools in evaluating the efficiency of this type of process. While E. crus-galli L. is a valuable tool in Cd phytoremediation programs, exposure time must be higher than 19 days to reduce concentrations of this metal in the water to conform to the CONAMA 357/2005 e 430/2011 standards.