Heterogeneous Photocatalysis Remediation of Wastewater Polluted by Indigoid Dyes

Organic dyes constitute one of the largest groups of wastewater’s pollutants. In general, they are released into the environment by textile industries. Approximately 100,000 dyes are widely used in the textile industry, and a large wastewater of dyestuff is generated annually. Among these, indigoid class is commercial dyes used mostly for cotton cloth dyeing. Indigo carmine (IC) is also one of the oldest dyes and still one of the most used in textile industry and is considered as a very toxic indigoid dye. Most toxic dyes are recalcitrant to biodegradation, causing a decrease in the efficiency of biological wastewater treatment plants. Titanium dioxide is a well-known photocatalyst mostly used in suspensions in photoreactions for wastewater treatment. The use of TiO2 has some advantages such as ease of handling, low cost, low toxicity, high photochemical reactivity, and non-specific oxidative attack ability. In this way, it can promote the degradation of different target organic compounds with little change of operational parameters. The aim of this chapter is to present the different approaches already used in our team for the remediation of waters containing IC mainly through heterogeneous photocatalysis with TiO2. Adsorption over activated carbon (AC) and photocatalytic degradation of IC mediated by titanium dioxide will be revised as well as some studies on the phototoxicity of the photoproducts with aquatic and terrestrial organisms. This chapter makes a comprehensive approach to the different results on the remediation of model effluents containing IC undertaken by this team of researchers

Human adenovirus in municipal solid waste leachate and quantitative risk assessment of gastrointestinal illness to waste collectors

Leachate is a variable effluent from waste management systems generated during waste collection and on landfills. Twenty-two leachate samples from waste collection trucks and a landfill were collected from March to December 2019 in the municipality of Rio de Janeiro (Brazil) and were analyzed for Human Adenovirus (HAdV), bacterial indicators and physico-chemical parameters. For viral analysis, samples were concentrated by ultra centrifugation and processed for molecular analysis using QIAamp Fast DNA Stool mini kit (R) for DNA extraction followed by nested-PCR and qPCR/PMA-qPCR TaqMan (R) system. HAdV was detected by nested-PCR in 100% (9/ 9) and 83.33% (12/13) of the truck and landfill leachate samples, respectively. Viral concentrations ranged from 8.31 x 10(1) to 6.68 x 107 genomic copies per 100 ml by qPCR and PMA-qPCR. HAdV species A, B, C, and F were characterized using nucleotide sequencing. HAdV were isolated in A549 culture cells in 100% (9/9) and 46.2% (6/13) from truck and landfill leachate samples, respectively. Regardless of the detection methods, HAdV concentration was predicted by the quantity of total suspended solids. A quantitative microbial risk assessment was performed to measure the probability of gastrointestinal (GI) illness attributable to inadvertent oral ingestion of truck leachate, revealing the higher probability of disease for the direct splashing into the oral cavity (58%) than for the gloved hand-to-mouth (33%). In a scenario where waste collectors do not wear gloves as protective personal equipment, the risk increases to 67%. This is the first study revealing infectious HAdV in solid waste leachate and indicates a potential health risk for waste collectors

Effect of titanium dioxide in the photocatalytic decomposition of persistent chemicals in the environment: textiles and dyes endocrine interfering

Submitted by Repositório Arca ([email protected]) on 2019-09-10T13:02:59Z No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) enrico_mendes.pdf: 2530016 bytes, checksum: c56f4b0c79906baf52c2683f3d2e6537 (MD5)Approved for entry into archive by Erasmo Martins ([email protected]) on 2019-10-02T13:40:14Z (GMT) No. of bitstreams: 2 enrico_mendes.pdf: 2530016 bytes, checksum: c56f4b0c79906baf52c2683f3d2e6537 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-10-02T13:40:14Z (GMT). No. of bitstreams: 2 enrico_mendes.pdf: 2530016 bytes, checksum: c56f4b0c79906baf52c2683f3d2e6537 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.O objetivo do presente trabalho foi estudar a degradação fotocatalítica de três corantes e um interferente endócrino mediado pelo dióxido de titânio (TiO2). Foi estudada a degradação fotocatalítica de dois azo corantes comerciais, respectivamente o C.I Reactive Black 5 e o C.I Reactive Red 239. Para esse estudo foi utilizado o TiO2 P25 Evonik como catalisador e os experimentos foram realizados em solução aquosa com reator artificial equipado com lâmpada de vapor de mercúrio 125W. Nesse estudo, foram avaliados os seguintes parâmetros: concentração de TiO2, tempo de irradiação, pH, concentração inicial de corante, presença de diferentes concentrações de peróxido de hidrogênio e degradação em sistema bi-compartimental para os dois azo corantes. O outro corante estudado foi o Índigo Carmine (IC). Primeiramente foi investigada a descoloração do corante em efluente modelo usando processo físico e químico para sua remoção. Os experimentos de descoloração do efluente contendo o corante IC foram realizados usando carvão ativado no escuro e com irradiação. Além disso, o efeito do carvão ativado/TiO2/UV foi avaliado pelo mesmo sistema. Os parâmetros da degradação do IC foram realizados, seguindo: concentração de TiO2, pH, concentração inicial de corante, presença de ânions inorgânicos, temperatura, concentração de peróxido de hidrogênio. A eficiência de três diferentes reatores (Reator 1 – reator do tipo batch com lâmpada vapor de mercúrio 125W; Reator 2 – reator do tipo batch equipado com 4 lâmpadas daylight 20W; Reator 3 – reator tubular de fluxo contínuo equipado com uma lâmpada daylight 20W) e reator batch com luz solar foram avaliados para degradação do IC. Além disso, otimizados experimentos foram realizados em planta piloto com compound parabolic collector reatores (CPC) na Plataforma Solar de Almería, Espanha, com TiO2 em suspensão e suportado. O IC foi estudado em diferentes tipos de águas, sendo elas: água destilada, água sintética moderadamente dura, água sintética e real de estação de tratamento de água residuária (ETAR). Testes ecotoxicológicos para o IC foram realizados em dois diferentes níveis tróficos de cadeia alimentar (Daphnia similis e Pseudokirchneriella subcapitata) e testes com minhocas Eisenia andrei. A degradação fotocatalítica do Bisfenol A (BPA) em diferentes tipos de águas na presença de TiO2 foi feita sob diferentes condições. O TiO2 em suspensão foi utilizado para comparar a eficiência da degradação do BPA (20 mgL-1 ) em batch e CPC reatores. O TiO2 foi suportado em esferas de vidro pelo método sol-gel e usado em reatores solares CPC em escala piloto para degradação do BPA (100 µgL-1 ). A influência das espécies reativas (OH• , O2 •- , h + ) foi avaliada. Testes ecotoxicológicos com minhocas Eisenia andrei também foram realizados para o BPA e seus produtos de degradação.The aim this study was evaluated the photocatalytic degradation mediated titanium dioxide (TiO2) for three dyes and one endocrine disruptor. The photocatalytic degradation of two commercial textile azo dyes, respectively C.I Reactive Black 5 and C.I Reactive Red 239 has been studied. TiO2 P25 Evonik was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated. The other dye studied was Indigo Carmine (IC). First was investigated the decolorization of a model water effluent containing indigo carmine dye under physical and chemical different treatments. Experiments on decolorization of the effluent containing indigo dye were performed using activated carbon in the dark and under irradiation. Furthermore the effect of activated carbon/TiO2/UV was tested for the same system. The effects of parameters in the IC degradation were evaluated under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2, pH of the solution, initial concentration of the dye, presence of inorganic anions, temperature and addition of different concentrations of hydrogen peroxide were investigated. The efficiency of three different artificial photoreactors (Reactor 1 – batch magnetically stirred reactor with 125 watts mercury vapor lamp; Reactor 2 - batch magnetically stirred reactor with 4 lamps daylight 20 watts; Reactor 3 - glass tubular continuous-flow reactor, illuminated inside by one daylight 20W lamp) were evaluated. Also, the same parameters were evaluated for batch solar experiments. Furthemore, the optimized experiments was performed in a solar compound parabolic collector (CPC) pilot plant in Plataforma Solar de Almería, Espanha, under suspended and supported TiO2. IC was spiked in several types of water such as distilled water, synthetic moderately hard freshwater, synthetic and real secondary municipal wastewater treatment plant (MWWTP). The ecotoxicological effects of IC were evaluated for two different food chain levels (Daphnia similis and Pseudokirchneriella subcapitata) and Eisenia andrei earthworms. Photocatalytic degradation of Bisphenol A (BPA) in waters and wastewaters in the presence of titanium dioxide (TiO2) was performed under different conditions. Suspensions of the TiO2 were used to compare the degradation efficiency of BPA (20 mgL-1 ) in batch and CPC reactors. A TiO2 catalyst supported on glass spheres beads was prepared (sol-gel method) and used in a CPC solar pilot plant for the photodegradation of BPA (100 µgL-1 ). The influence of OH• , O2 •- , h + on the BPA degradation were evaluated. Some toxicological effects of BPA and its photoproducts on Eisenia andrei earthworms were evaluated

Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO2 P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO2 reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes

Surface photocatalysis: a study of the thickness of TiO(2) layers on the photocatalytic decomposition of soluble indigo blue dye

Submitted by Alexandre Sousa ([email protected]) on 2015-10-15T11:11:42Z No. of bitstreams: 1 Rev_Chim_62-462-468.pdf: 224734 bytes, checksum: cd14a024c8ccbe88a1faf1945ccd45dd (MD5)Approved for entry into archive by Alexandre Sousa ([email protected]) on 2015-10-15T11:18:01Z (GMT) No. of bitstreams: 1 Rev_Chim_62-462-468.pdf: 224734 bytes, checksum: cd14a024c8ccbe88a1faf1945ccd45dd (MD5)Approved for entry into archive by Alexandre Sousa ([email protected]) on 2015-10-15T11:57:54Z (GMT) No. of bitstreams: 1 Rev_Chim_62-462-468.pdf: 224734 bytes, checksum: cd14a024c8ccbe88a1faf1945ccd45dd (MD5)Made available in DSpace on 2015-10-15T11:57:54Z (GMT). No. of bitstreams: 1 Rev_Chim_62-462-468.pdf: 224734 bytes, checksum: cd14a024c8ccbe88a1faf1945ccd45dd (MD5) Previous issue date: 2011Universidade Técnica de Lisboa. Instituto Superior Técnico. Centro de Química-Física Molecular. Lisboa, Portugal / Instituto Politécnico de Portalegre. Escola Superior de Tecnologia e Gestão. Lugar da Abadesssa, Portalegre, Portugal.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sérgio Arouca. Rio de Janeiro, RJ, Brasil.Universidade Federal de Juiz de Fora. Departamento de Alimentos e Toxicologia. Juiz de Fora, MG, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde. Departamento de Química. Rio de Janeiro, RJ, Brasil.Universidade Técnica de Lisboa. Instituto Superior Técnico. Centro de Química-Física Molecular. Lisboa, Portugal.Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sérgio Arouca. Rio de Janeiro, RJ, Brasil.The effect of the thickness of a TiO2 layer coated on glass slides, obtained by the use of a simple multiple soaking method, was tested evaluating its effect on the efficiency of photodegradation of adsorbed soluble indigo blue dye on it. Photodegradation was undertaken on a laboratorial bench top photoreactor, equipped with a mercury lamp covered by a glass bulb, and photodegradation results were monitored directly on the photocatalytic surface by ground state diffuse reflectance

Solar CPC Pilot Plant Photocatalytic Degradation of Indigo Carmine Dye in Waters and Wastewaters Using Supported-TiO2: Influence of Photodegradation Parameters

The photocatalytic degradation of indigo carmine (IC) dye in the presence of titanium dioxide under different conditions was reported. Several factors which interfere with the photodegradation efficiency as catalyst concentration, pH, initial concentration of dye, presence of inorganic anions, temperature, and the addition of hydrogen peroxide were studied under artificial irradiation with a 125 W mercury vapor lamp. Additionally, the catalyst supported on glass spheres was used for the photocatalytic degradation of the dye present in several types of waters in a CPC solar pilot plant. The photocatalytic products, carboxylic acids, and SO42- and NH4+ were followed during IC mineralization. Formate, acetate, and oxalate were detected in real MWWTP secondary effluent. The mineralization efficiency was of 42 and 21% using in suspension and supported TiO2, respectively. In order to evaluate biological effects, Eisenia andrei earthworms were used as a model organism. No significant difference (P>0.05) of weight was observed in the earthworm submitted to different concentrations of IC and its photoproducts. The photocatalytic degradation of IC on TiO2 supported on glass spheres suffered strong influence of the water matrix; nevertheless the method has the enormous advantage that it eliminates the need for the final catalyst removal step, reducing therefore the cost of treatment

Acute toxicity of single and combined rare earth element exposures towards Daphnia similis

The increasing use of Rare Earth Elements (REE) in emerging technologies, medicine and agriculture has led to chronic aquatic compartment contamination. In this context, this aimed to evaluate the acute toxic effects of lanthanum (La), neodymium (Nd) and samarium (Sm), as both single and binary and ternary mixtures on the survival of the microcrustacean Daphnia similis. A metal solution medium with (MS) and without EDTA and cyanocobalamin (MSq) as chelators was employed as the assay dilution water to assess REE bioavailability effects. In the single exposure experiments, toxicity in the MS medium decreased following the order La > Sm > Nd, while the opposite was noted for the MSq medium, which was also more toxic than the MS medium. The highest MS toxicity was observed for the binary Nd + La (1:1) mixture (EC50 48 h of 11.57 ± 1.22 mg.L−1) and the lowest, in the ternary Sm + La + Nd (2:2:1) mixture (EC50 48 h 41.48 ± 1.40 mg.L−1). The highest toxicity in the MSq medium was observed in the single assays and in the binary Sm + Nd (1:1) mixture (EC50 48 h 10.60 ± 1.57 mg.L−1), and the lowest, in the ternary Sm + La + Nd (1:2:2) mixture (EC50 48 h 36.76 ± 1.54 mg.L−1). Concerning the MS medium, 75 % of interactions were additive, 19 % antagonistic, and 6 % synergistic. In the MSq medium, 56 % of interactions were synergistic and 44 % additive. The higher toxicity observed in the MSq medium indicates that the absence of chelators can increase the concentrations of more toxic free ions, suggesting that the MS medium should be avoided in REE assays. Additive interactions were observed in greater or equivalent amounts in both media and were independent of elemental mixture ratios. These findings improve the understanding of environmental REE effects, contributing to the establishment of future guidelines and ecological risk calculations