Fungos basidiomicetos podem promover a descoloração de efluentes têxteis por meio de um complexo multienzimático inespecífico. Neste trabalho, a descoloração e a toxicidade de efluentes tratados por fungos (Peniophora cinerea, Pleuorotus ostreatus e Trametes villosa) imobilizados em bucha vegetal foram avaliadas em pequena escala e em biorreator. Em pequena escala, P. ostreatus foi o mais efetivo para o efluente azul e T. villosa foi o mais efetivo para o efluente amarelo, enquanto que ambos destacaram-se para o efluente vermelho. Substâncias presentes no banho de alvejamento interferiram no tratamento. Observou-se redução da toxicidade aguda e fitotoxicidade na maior parte dos tratamentos. Os tratamentos fúngicos não reduziram valores de DQO, COT, SST, turbidez e condutividade. O aumento de escala (biorreator de 5 L) mostrou-se eficiente quanto aos níveis de descoloração. A reutilização da biomassa fúngica garantiu bons níveis de descoloração, porém com aumento da toxicidade. O tratamento foi satisfatório por promover a redução da cor e toxicidade. / Basidiomycete fungi can promote the decolorization of textile effluents using a nonspecific multienzyme complex. In this study, the decolorization and toxicity of effluents treated by fungi (Peniophora cinerea, Pleuorotus ostreatus and Trametes villosa) immobilized in Luffa cylindrica were evaluated in a small scale and in bioreactor. In the small scale, P. ostreatus was the most effective for the blue effluent and T. villosa was the most effective for the yellow effluent, while both stood out for the red effluent. Substances in the bleaching bath interfered with the treatment. It was observed a reduction in the acute toxicity and phytotoxicity in most treatments. The fungal treatment did not reduce the values of COD, TOC, TSS, turbidity and conductivity. The increased scale (5L bioreactor) proved to be efficient in reducing the degree of decolorization. The reuse of fungal biomass attained a good level of decolorization but increased the toxicity. The treatment was satisfactory in promoting the reduction of color and toxicity.

Made available in DSpace on 2014-06-11T19:27:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-17Bitstream added on 2014-06-13T20:35:52Z : No. of bitstreams: 1 almeida_acm_me_rcla.pdf: 908754 bytes, checksum: c67dc89a044d50c60fbdc87558d820a3 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O uso de biodigestores anaeróbios é uma versátil alternativa para produção de biomassa microbiana a partir de resíduos orgânicos. O reaproveitamento das sobras alimentares, produzidas pelo Restaurante Universitário da Unesp Campus Rio Claro, foi o responsável pela produção de um Inóculo Líquido Residual (I.L.R.) utilizado como agente biodegradador e biossorvente para os corantes azóicos “Acid Yellow 25” e “Direct Violet 51” de importante destaque industrial. O projeto dividiu-se em duas etapas, a primeira contemplando a produção do inóculo em grande escala (biodigestor de fluxo contínuo) e a segunda em escala de laboratorial (biodigestor em batelada). Os resultados da análise microbiológica revelaram a presença predominante de bactérias acidogênicas e de leveduras em menor escala. Estes microrganismos foram aplicados como inóculo nas soluções dos dois corantes em condições variadas de pH (2,50; 4,50 e 6,50). A análise dos produtos formados a partir da interação com o I.L.R demonstraram as potencialidades biodegradativas e biossorventes do consórcio microbiano e sua ação diferenciada de acordo com a mudança de pH.As aminas aromáticas e sulfonadas, formadas após a redução da ligação azóica, foram estudada a partir do sobrenadante dos tratamentos dos corantes através do uso dos métodos difundidos do UV-Vis e do HPLC aliados às analises vanguardistas do FTIR. / The use of anaerobic bioreactor is a versatile alternative for the production of microbial biomass from organic waste. The reuse of the leftovers from the University Restaurant of Unesp Rio Claro Campus, was responsible for producing a Residual Liquid Inoculum (R.L.I.) used as a biodegradator and biosorptive agent for two azo dyes Acid Yellow 25 and Direct Violet 51 with a major role in the industrial scenery. The project was divided in two steps, the first covering the production of the inoculum in large scale (continuous flow bioreactor) and the second in bench-scale (in-batch bioreactor) The results of the microbiological analysis revealed a predominant presence of acidogenic bacteria and a few yeasts. These microorganisms were used as inoculum in both dye solutions at different pH conditions (2.50, 4.50 and 6.50) The analysis of the resultant by-products demonstrated the biodegradation and biosorptive potential of the consortium and its differentiated pH-regulated action. The aromatic sulfonated amines, formed after the reduction of the azoic bounds, were studied through the spreaded analytic methods of UV-Vis and HPLC in conjunct with the vanguard of FTIR device.

Orientador: Carlos Renato Corso / Banca: Sandra Mara Martins Franchetti / Banca: Sandra Regina Ceccato Antonini / Resumo: O uso de biodigestores anaeróbios é uma versátil alternativa para produção de biomassa microbiana a partir de resíduos orgânicos. O reaproveitamento das sobras alimentares, produzidas pelo Restaurante Universitário da Unesp Campus Rio Claro, foi o responsável pela produção de um Inóculo Líquido Residual (I.L.R.) utilizado como agente biodegradador e biossorvente para os corantes azóicos "Acid Yellow 25" e "Direct Violet 51" de importante destaque industrial. O projeto dividiu-se em duas etapas, a primeira contemplando a produção do inóculo em grande escala (biodigestor de fluxo contínuo) e a segunda em escala de laboratorial (biodigestor em batelada). Os resultados da análise microbiológica revelaram a presença predominante de bactérias acidogênicas e de leveduras em menor escala. Estes microrganismos foram aplicados como inóculo nas soluções dos dois corantes em condições variadas de pH (2,50; 4,50 e 6,50). A análise dos produtos formados a partir da interação com o I.L.R demonstraram as potencialidades biodegradativas e biossorventes do consórcio microbiano e sua ação diferenciada de acordo com a mudança de pH.As aminas aromáticas e sulfonadas, formadas após a redução da ligação azóica, foram estudada a partir do sobrenadante dos tratamentos dos corantes através do uso dos métodos difundidos do UV-Vis e do HPLC aliados às analises vanguardistas do FTIR. / Abstract: The use of anaerobic bioreactor is a versatile alternative for the production of microbial biomass from organic waste. The reuse of the leftovers from the University Restaurant of Unesp Rio Claro Campus, was responsible for producing a Residual Liquid Inoculum (R.L.I.) used as a biodegradator and biosorptive agent for two azo dyes Acid Yellow 25 and Direct Violet 51 with a major role in the industrial scenery. The project was divided in two steps, the first covering the production of the inoculum in large scale (continuous flow bioreactor) and the second in bench-scale (in-batch bioreactor) The results of the microbiological analysis revealed a predominant presence of acidogenic bacteria and a few yeasts. These microorganisms were used as inoculum in both dye solutions at different pH conditions (2.50, 4.50 and 6.50) The analysis of the resultant by-products demonstrated the biodegradation and biosorptive potential of the consortium and its differentiated pH-regulated action. The aromatic sulfonated amines, formed after the reduction of the azoic bounds, were studied through the spreaded analytic methods of UV-Vis and HPLC in conjunct with the vanguard of FTIR device. / Mestre

O presente trabalho avaliou o potencial da enzima HRP no descoramento dos corantes têxteis: Azul Drimaren X-3LR (DMBLR), Azul Drimaren X-BLN (DMBBLN), Rubinol Drimaren X-3LR (DMR) e Azul Drimaren CL-R (RBBR). Parâmetros como concentração do corante, temperatura, concentração de peróxido de hidrogênio (H2O2) e tempo de reação foram otimizados. Os ensaios de descoramento dos corantes foram realizados a partir desses resultados. As melhores condições reacionais determinadas para os corantes estudados foram: concentração do corante = 120 mg L-1, temperatura = 35C, concentração de H2O2 = 0,55 mM e tempo de reação = 1 hora. Os percentuais de descoramento dos corantes DMBLR, DMBBLN, DMR e RBBR, após o tratamento enzimático foi de 99, 77, 94 e 97%, respectivamente. O tempo reacional de 5 minutos foi suficiente para os corantes DMBLR e RBBR apresentarem elevada porcentagem de descoramento, 96% para ambos. Já os corantes DMBBLN e DMR só apresentaram elevado grau de descoramento após 1 hora de reação, sendo o corante DMBBLN o mais recalcitrante, apresentando uma melhora de 10% na porcentagem de descoramento, após 24 horas de reação. Além do grau de descoramento, também foi avaliada a toxicidade dos corantes antes e após o tratamento enzimático utilizando Daphnia pulex e Artemia salina como bioindicadores de toxicidade. Resultados toxicológicos utilizando Daphnia pulex não foram conclusivos, indicando que esse bioindicador não foi adequado para avaliar a toxicidade dos corantes estudados no meio reacional utilizado. Com o uso da Artemia salina na avaliação toxicológica foi observado uma redução da toxicidade para os corantes DMBLR, DMR e RBBR após tratamento enzimático, e um aumento da toxicidade não significativo para o corante DMBBLN. Os resultados obtidos no trabalho ressaltam a eficiência da enzima HRP no descoramento dos corantes têxteis estudados, sem a geração de produtos tóxicos e prejudiciais ao meio ambiente / The aim of the present study was to evaluate the potential of the Horseradish peroxidase (HRP) enzyme in the decolorization of textile dyes Drimaren Blue X-3LR (DMBLR), Drimaren Blue X-BLN (DMBBLN), Drimaren Rubinol X-3LR (DMR) and Drimaren Blue CL-R (RBBR). Parameters such as concentration of the dye, temperature, concentration of hydrogen peroxide (H2O2) and reaction time were optimized. The optimum reaction conditions determined for the studied dyes were: concentration of the dye = 120 mg L-1, temperature = 35 C, concentration of H2O2 = 0.55 mM and reaction time = 1 h. The decolorization percentage of dyes DMBLR, DMBBLN, DMR and RBBR after enzymatic treatment was 99, 77, 94 and 97%, respectively. The reaction time of only 5 minutes presented high decolorization percentage for both dyes DMBLR and RBBR, about 96 %. However dyes DMBBLN and DMR showed high decolorization degree in 1 h of reaction and the dye DMBBLN, being the most recalcitrant, exhibited an improvement of 10% in the decolorization percentage after 24 h of reaction. Besides the decolorization degree, the toxicity of the studied dyes was also evaluated before and after enzymatic treatment using Daphnia pulex and Artemia salina as bioindicators. The toxicological results using Daphnia pulex were not conclusive, indicating that it was not an appropriate bioindicator to evaluate the toxicity of the tested dyes. Meanwhile when using Artemia salina for toxicological evaluation it was observed a reduction of toxicity for dyes DMBLR, DMR and RBBR after enzymatic treatment, and a not significant increase in toxicity for the dye DMBBLN. In conclusion, the obtained results emphasize the efficiency of the HRP enzyme in the decolorization of the studied textile dyes, without the generation of toxic and harmful products to the environment

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-11-30T08:24:16Z No. of bitstreams: 2 Tese - Claudinei Sousa Lima - 2015.pdf: 4697944 bytes, checksum: 7602b1a52d5ff89353f1980ba35380a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-11-30T08:26:27Z (GMT) No. of bitstreams: 2 Tese - Claudinei Sousa Lima - 2015.pdf: 4697944 bytes, checksum: 7602b1a52d5ff89353f1980ba35380a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-11-30T08:26:27Z (GMT). No. of bitstreams: 2 Tese - Claudinei Sousa Lima - 2015.pdf: 4697944 bytes, checksum: 7602b1a52d5ff89353f1980ba35380a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-04-06 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / A real sample of textile wastewater was successfully decolorized through a simple, fast and efficient photocatalytic treatment using polypyrrole as catalyst. In the optimized operational conditions, the photocatalytic treatment resulted in 95.8% decrease in the units of color and 91.2% photodecomposition. Photocatalysis reduced the COD values from 1111.04 mg L1 to 71.43 mg L1, evidencing 93.6% reduction in the organic matter to be discharged. TOC was also efficiently reduced from 156.75 to 51.74. The efficiency of the photocatalytic process was maintained during repeated use when cycles of photocatalysis were followed by redoping of polypyrrole with 0.1 mol L1 HCl solution. The same photodecomposition efficiency was achieved using sunlight irradiation for 30 min, with values of photodecomposition up to 98%. Tests of toxicity using Artemia saline resulted in 96.7% survival, indicating that the products generated in the photodecomposition are non-toxic. Tests made with an artificial effluent showed the same efficiency in wastewater color removal indicating that the process may be suitable for treating effluents with different colors with same efficiency. In this way, photocatalytic treatment may be applied on photodecomposition of textile effluent, independent of the predominant color present in the effluent. / Uma amostra real de efluente têxtil foi descorada com sucesso através de um tratamento fotocatalítico simples, rápido e eficiente usando polipirrol como catalisador. Nas condições operacionais optimizadas, o tratamento fotocatalítico resultou em 95,8% de diminuição nas unidades de cor e 91,2% fotodecomposição. A fotocatálise reduziu os valores de Demanda Química de Oxigênio (DQO) de 1111,04 mg.L-1 para 71,43 mg.L-1, evidenciando redução de 93,6% da matéria orgânica a ser descartada nos corpos receptores. O Carbono Orgânico Total (COT) também foi reduzido de forma eficiente 156,75 - 51,74 ppm . A eficiência do processo fotocatalítico foi mantida durante o uso repetido, quando os ciclos de fotocatálise foram seguidos por redopagem do polipirrol com uma solução de HCl 0,1 mol.l-1. A mesma eficiência de fotodecomposição foi conseguida utilizando irradiação solar durante 30 minutos, com valores de fotodecomposição até 98%. Os testes de toxicidade usando Artemia salina, resultaram em 96,7% de sobrevivência, o que indica que os produtos gerados na fotodecomposição não são tóxicos. Testes feitos com o um efluente artificial mostraram a mesma eficiência na remoção da cor do efluente indicando que o processo pode ser adequado a tratar efluentes artificias que permitiriam realização de experimentos sem a interferência de variações da cor do efluente em função cor predominante produzida no dia da coleta.

The current study aims towards a holistic utilization of agro-waste rice straw (RS) to synthesize nanosilica (SiNPs) employing the sol–gel method. The effect of ashing temperature was evaluated for the synthesis process. X-ray diffraction demonstrated a broad spectrum at 21.22° for SiNPs obtained using RSA-600, signifying its amorphous nature, whereas crystalline SiNPs were synthesized using RSA-900. The EDX and FTIR spectra confirmed the significant peaks of Si and O for amorphous SiNPs, confirming their purity over crystalline SiNPs. FE-SEM and TEM micrographs indicated the spheroid morphology of the SiNPs with an average size of 27.47 nm (amorphous SiNPs) and 52.79 nm (crystalline SiNPs). Amorphous SiNPs possessed a high surface area of 226.11 m2/g over crystalline SiNPs (84.45 m2/g). The results obtained attest that the amorphous SiNPs possessed better attributes than crystalline SiNPs, omitting the need to incorporate high temperature. Photocatalytic degradation of methylene blue using SiNPs reflected that 66.26% of the dye was degraded in the first 10 min. The degradation study showed first-order kinetics with a half-life of 6.79 min. The cost-effective and environmentally friendly process offers a sustainable route to meet the increasing demand for SiNPs in industrial sectors. The study proposes a sustainable solution to stubble burning, intending towards zero waste generation, bioeconomy, and achieving the Sustainable Development Goals (SDGs), namely SDG 13(Climate Action), SDG 3(Good health and well-being), SDG 7(use of crop residues in industrial sectors) and SDG 8 (employment generation).

In many technical applications chemical reactions are used. One of these is a so called decolorization, in which an ion exchange resin is used to remove a dye from water. To apply this decolorization technique a Rotating Bed Reactor, or RBR for short, can be used. It is filled with the ion exchange resin and spun inside the water. Whilst spinning, the reactor percolates the water, letting it interact with the ion exchange resin and thus removing the dye. This project aims to use Computational Fluid Dynamics (CFD) as a tool to create a model for the decolorization process when a RBR is used. The goal is to achieve a reaction model for the process that can be applied to various RBR models, i.e. scaled, to aid for example product development and research. A decolorization process in which methylene blue is removed from deionized water using a SpinChem S2 RBR inside a V2 vessel, using a NRW 1160 ion exchange resin, is investigated. Experiments are conducted where the concentration of methylene blue in deionized water is measured during the decolorization process using a transmittance probe. From the experimental results a linear regression model is fitted to achieve a model for the reaction's rate constant, determining its reaction rate, depending on the fluid velocity inside the RBR and the temperature of the fluid. CFD is used to find the flow field for different rotational speeds of the RBR inside the vessel. Using the steady-state flow field species transport simulations are done using the created reaction model. This is done to compare numerical simulations to experimental results. The results show that the created reaction model can predict the time taken to absorb the methylene blue onto the ion exchange resin. Deviations from the exact decay rate of methylene blue concentration is seen, and are concluded to come from conversion of global reaction rate in the vessel to local reaction rate inside the RBR. The reaction model has not been tested explicitly on other types of RBR, thus nothing can be said about its performance. However, care has been taken to not include any RBR geometry dependent parameters in the model.

Wastewater from the textile industry is difficult to treat effectively due to the prevalent use and wide variety of synthetic dyes that are resistant to conventional treatment methods. White-rot fungi, such as Trametes versicolor, have been found to be effective in decolorizing many of these synthetic dyes and current research is focusing on their application to wastewater treatment. Although numerous studies have been conducted on the ability of both living and nonliving Trametes versicolor to separately decolorize textile dyes, no studies were found to have investigated the use of a mixture of live and dead fungus for decolorization. This study explored potential interactions between live and dead, autoclaved Trametes versicolor biomass in a mixed system by utilizing a series of batch tests with two structurally different synthetic textile dyes. Samples were analyzed by spectrophotometer and compared with controls to determine the effect of any interactions on decolorization. The results of this study indicate that an interaction between living and nonliving biomass occurred that affected the specific dye removal for both Reactive Blue 19, an anthraquinone textile dye, and Reactive Orange 16, an azo textile dye. This interaction was seen to improve the specific dye removal during the first 10-46 hours of experimentation but then diminish the specific dye removal after this period. This effect could be due to hydrophobins, which are surface-active proteins excreted by live fungi that may alter hydrophobicity. Additionally, the presence of adsorptive dead biomass could affect dye contact with degrading enzymes released from the live fungus. By expanding current knowledge of the interactions that take place in a fungal bioreactor and their effect on textile dye decolorization, this research aims to inspire more effective and less costly bioreactor designs for the treatment of textile wastewater.

As soluções convencionais de tratamento biológico de corantes azo são baseadas em processos anaeróbio-aeróbios ocorrendo em unidades distintas. Este estudo avaliou o uso da aeração intermitente para a descoloração do Direct Black 22 (DB22) e biodegradação simultânea de subprodutos tóxicos no mesmo compartimento reacional. Os microrganismos utilizados foram obtidos de florestas tropicais e previamente adaptados a concentrações crescentes de DB22 (10-32,5 mg.L-1) em meio de cultivo. Os efeitos da concentração inicial de glicose (1 – 2 – 3 g.L-1) e aeração intermitente (0 – 4 – 8 h.d-1) sobre a descoloração, constante de descoloração e remoção de demanda química de oxigênio (DQO) foram investigados por planejamento fatorial e análise de superfície de resposta. Os testes foram conduzidos com água residuária (AR) que simulava a composição dos efluentes de lavanderias têxteis do agreste pernambucano. Os resultados demonstraram que a descoloração no longo prazo não foi inibida para ciclos de aeração de até 4 h.d-1, embora menores velocidades de remoção de cor tenham sido obtidas nestas condições. Os efeitos negativos da aeração foram significativamente reduzidos pelo aumento da concentração de glicose na AR. Ademais, a remoção de DQO foi potencializada com o aumento da frequência de aeração. Após descoloração do DB22 nos ensaios não aerados, verificou-se a formação de picos de absorbância relacionados à presença de aminas aromáticas ou outros intermediários da descoloração redutiva; o que não ocorreu nos experimentos aerados. Estes fatores resultaram em menor toxicidade à Daphnia magna em experimento modelo com nível intermediário de aeração. O sequenciamento do gene 16S rRNA na plataforma Illumina HiSeq revelou a presença de gêneros de bactérias conhecidos por produzirem enzimas envolvidas na biodegradação do azo. Observou-se, ainda, uma correlação positiva entre diversidade microbiana e eficiência de descoloração. Os resultados sugerem que a estratégia de aeração intermitente, corretamente implementada, pode melhorar a performance do tratamento biológico de efluentes têxteis que contém azo-corantes. / Conventional technologies for biological treatment of azo dyes are based on anaerobic-aerobic processes taking place into distinct units. This study evaluated the use of intermittent aeration strategy for decolorization of the Direct Black 22 (DB22) and simultaneous biodegradation of metabolites. Microorganisms were obtained from tropical forests and previously acclimated to increasing concentrations of DB22 (10-32.5 mg.L-1) in growth medium. Effects of initial glucose concentration (1 – 2 – 3 g.L-1) and intermittent aeration (0 – 4 – 8 cycles.d-1) on response variables decolorization, decolorization rate, and removal of chemical oxygen demand (COD) were investigated using factorial design and response surface analysis. Tests were conducted using a wastewater that simulated the composition of textile laundry effluents from a region with harsh climate in the state of Pernambuco, known as agreste pernambucano. Results showed long-term decolorization was not impaired for up to 4 cycles.d-1 of aeration, although a decrease in color removal velocities was observed in these experiments. Negative impacts of aeration were significantly reduced by increasing initial glucose concentration. Moreover, COD removal was enhanced with increased aerations levels. After DB22 degradation in non-aerated batches, the formation of absorbance peaks associated with aromatic amines and other byproducts of reductive decolorization was observed; which did not occur in the aerated experiments. These resulted in lower toxicity to Daphnia magna in model experiment using intermediate level of aeration. 16S rRNA gene sequencing on the Illumina HiSeq platform revealed the presence of several bacteria known to produce enzymes involved in azo compounds degradation. Furthermore, a positive correlation between microbial diversity and decolorization efficiency was observed. Results suggest intermittent aeration strategy can enhance biological treatment of textile effluents containing azo dyes when correctly implemented.

Melanoidin, a high molecular-weight heterogeneous pollutant in the effluents of molasses-using industries, poses a significant threat to the environment due to its non-biodegradability, unpleasant odour, and harmful effect. Various advanced oxidation processes (AOPs) that produce reactive oxygen species (ROS) are used for the degradation of melanoidins. Heterogeneous photo-Fenton process has emerged as a promising alternative approach in wastewater treatment owing to its enhanced catalytic activity, lower hydrogen peroxide (H2O2) consumption, and reusability of the catalyst. In this work, we investigated the photo-Fenton oxidation of melanoidins using heterogeneous catalyst ZnO@SnOx@nZVI supported on a flexible substrate. The effects of reaction pH, amount of catalyst and H2O2 on color and chemical oxygen demand (COD) removal, as well as the removal kinetics, were studied. It is found that the developed heterogeneous catalyst can lead to 97.3% decolorization of melanoidin (7000 COD) after 4 hours irradiation of simulated sunlight at pH 6 with a much lower dosage of H2O2 than the stoichiometric ratio with respect to COD. The generation of ·OH free radicals and residual H2O2 were monitored to understand the mechanism of melanoidin degradation at near-neutral pH with insufficient H2O2. The findings of this work have significant implications in treatment of non-biodegradable organic pollutants, owing to the advantages in avoiding low pH treatment condition, reducing the cost of H2O2, and enhanced chemical stability of photo-Fenton catalyst. / Melanoidin, en heterogen förorening med hög molekylvikt i avloppsvatten från industrier som använder melass, utgör ett betydande hot mot miljön på grund av dess icke-biologiska nedbrytbarhet, obehagliga lukt och skadliga effekt. Olika avancerade oxidationsprocesser (AOP) som producerar reaktiva syreföreningar (ROS) används för nedbrytning av melanoidiner. Heterogen foto-Fenton-process har framstått som ett lovande alternativ för avloppsrening på grund av dess förbättrade katalytiska aktivitet, lägre väteperoxid (H2O2) förbrukning och återanvändbarhet av katalysatorn. I detta arbete undersökte vi foto-Fenton-oxidationen av melanoidiner med hjälp av heterogen katalysator ZnO@SnOx@nZVI som stöds på ett flexibelt substrat. Effekterna av reaktionens pH, mängden katalysator och H2O2 på färg och avlägsnande av kemisk syreförbrukning (COD), liksom avlägsnandets kinetik, studerades. Det visade sig att den utvecklade heterogena katalysatorn kan leda till 97,3% avfärgning av melanoidin (7000 COD) efter 4 timmars bestrålning av simulerat solljus vid pH 6 med en mycket lågre dosering av H2O2 än det stökiometriska förhållandet med avseende på COD. Generering av ·OH fria radikaler och kvarvarande H2O2 övervakades för att förstå mekanismen för nedbrytning av melanoidin vid nära neutralt pH med otillräcklig H2O2. Resultaten av detta arbete har betydande konsekvenser vid behandling av icke- biologiskt nedbrytbara organiska föroreningar, på grund av fördelarna med att undvika behandlingsförhållanden med lågt pH, minska kostnaden för H2O2 och förbättrad kemiska stabilitet hos foto-Fenton-katalysatorn.