Performance Evaluation of the SrZrxSn1-xO3 Photocatalytic System for Remazol Yellow Dye Degradation Employing Box-Behnken Design

Contamination of effluents often occurs due to improper disposal of textile dyes or their by-products. These can often be carcinogenic and/or mutagenic to the biome. Given the above, the need for effective methods for treating effluents is clear. This treatment occurs by biological, physical, and/or chemical processes. Regarding chemical processes, heterogeneous photocatalysis stands out, mainly because it guarantees an effective degradation of contaminants. In this sense, mixed metal oxides, act as photocatalysts and constitute structures capable of producing a large family of solids with physical properties suitable for the degradation of many pollutants. Modified ABO3 perovskites, as in the case of the SrZrxSn1-xO3 semiconductor system, are effective in the degradation of textile dyes in effluents. The present work aimed to use the Box-Behnken model to evaluate the performance of the oxides resulting from the structural modifications of the perovskite SrZrxSn1-xO3 system, concerning the discoloration of the golden yellow dye remazol. The synthesized oxides were characterized by instrumental techniques and a Box-Behnken 34 project was developed. From this, the influence of some factors such as structural modification, oxide mass, exposure time, and the number of UVC lamps was evaluated. The discoloration of the dye was monitored from the attenuation of the absorbance at the wavelength 411 nm. According to the results obtained, the highest percentage of discoloration was obtained using the modified oxide SrZr0,25Sn0,75O3 for an approximate time of 6 hours in contact with 1 UVC lamp.

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Titanium dioxide immobilization in recycled aluminum net for degradation of textile dye by Heterogeneous Photocatalysis trough neural networks

Revista Eletrônica em Gestão Educação e Tecnologia Ambiental ◽

10.5902/2236117037718 ◽

2019 ◽

Vol 23 ◽

pp. 27

Author(s):

Ingrid Larissa da Silva Santana ◽

Ada Azevedo Barbosa ◽

Marina Gomes Silva ◽

Ramon Vinicius Santos de Aquino ◽

Naiana Santos da Cruz Santana Neves ◽

...

Keyword(s):

Dye Degradation ◽

Film Formation ◽

Supported Catalyst ◽

Absolute Error ◽

Heterogeneous Photocatalysis ◽

Textile Dye ◽

Degradation Kinetic ◽

Tio2 Anatase ◽

Degradation Rates ◽

Golden Yellow

In this work, aluminum net crafted (recycled) were used as TiO2 support for the treatment of textile dye Remazol golden yellow (RGY 150). The immobilization of 200mg of TiO2 was accomplished after aluminum net calcination. The following experiments were carried out in a photocatalytic bench reactor: preliminary tests, a 23 factorial experimental design with best system and the degradation kinetic in systems with TiO2 supported on aluminum net.It was observed characteristic peaks of aluminum and TiO2 (anatase and rutile) by XRD and the catalyst film formation was verified by SEM. The system UV/H2O2/TiO2 performed higher efficiency, with 99% of dye degradation in 50 minutes, followed by the system UV/H2O2/TiO2sp with 93% of dye degradation. Whereas the supported catalyst presents execution advantages and high degradation rates, the factorial design was realized for this system, displaying best degradation (100% degradation in 35 minutes). It was obtained k = 0.114 min-1 and R² = 0.994 in a pseudo-first-order model adjustment system. The use of artificial neural network was proven to be efficient to predict the degradation of a textile dye, with an absolute error of 0.0181. After treatment, there was a decrease of dye toxicity.

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Microbial Degradation of Rubber: Actinobacteria

Polymers ◽

10.3390/polym13121989 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1989

Author(s):

Ann Anni Basik ◽

Jean-Jacques Sanglier ◽

Chia Tiong Yeo ◽

Kumar Sudesh

Keyword(s):

Double Bond ◽

Chemical Processes ◽

Molecular Characteristics ◽

Daily Lives ◽

Structural Modifications ◽

Synthetic Rubber ◽

Rubber Waste ◽

Environmentally Responsible ◽

By Products ◽

Responsible Manner

Rubber is an essential part of our daily lives with thousands of rubber-based products being made and used. Natural rubber undergoes chemical processes and structural modifications, while synthetic rubber, mainly synthetized from petroleum by-products are difficult to degrade safely and sustainably. The most prominent group of biological rubber degraders are Actinobacteria. Rubber degrading Actinobacteria contain rubber degrading genes or rubber oxygenase known as latex clearing protein (lcp). Rubber is a polymer consisting of isoprene, each containing one double bond. The degradation of rubber first takes place when lcp enzyme cleaves the isoprene double bond, breaking them down into the sole carbon and energy source to be utilized by the bacteria. Actinobacteria grow in diverse environments, and lcp gene containing strains have been detected from various sources including soil, water, human, animal, and plant samples. This review entails the occurrence, physiology, biochemistry, and molecular characteristics of Actinobacteria with respect to its rubber degrading ability, and discusses possible technological applications based on the activity of Actinobacteria for treating rubber waste in a more environmentally responsible manner.

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Pre-Industrial Experience in Solar Photocatalytic Mineralization of Real Wastewaters. Application to Pesticide Container Recycling

Water Science & Technology ◽

10.2166/wst.1999.0583 ◽

1999 ◽

Vol 40 (4-5) ◽

pp. 123-130 ◽

Cited By ~ 2

Author(s):

S. Malato ◽

J. Blanco ◽

C. Richter ◽

B. Milow ◽

M. I. Maldonado

Keyword(s):

Organic Contaminants ◽

Toxic Waste ◽

Experimental Plant ◽

Electron Hole ◽

Particulate Suspensions ◽

Photocatalytic System ◽

Commercial Pesticide ◽

Pesticide Container ◽

By Products ◽

Hole Recombination

Particulate suspensions of TiO2 irradiated with natural solar tight in a large experimental plant catalyse the oxidation of organic contaminants. The problem in using TiO2 as a photocatalyst is electron/hole recombination. One strategy for inhibiting e−/h+ recombination is to add other (irreversible) electron acceptors to the reaction. In many highly toxic waste waters where degradation of organic pollutants is the major concern, the addition of an inorganic anion to enhance the organic degradation rate may be justified. For better results, these additives should fulfil the following criteria: dissociate into harmless by-products and lead to the formation of ·OH or other oxidising agents. In this paper, we attempt to demonstrate the optimum conditions for the treatment of commercial pesticide rinsates found in the wastewater produced by a pesticide container recycling plant. The experiments were performed in one of the pilot plants of the largest solar photocatalytic system in Europe, the Detoxification Plants of the Plataforma Solar de Almería (PSA), in Spain. After testing ten different commercial pesticides, results show that peroxydisulphate enhances the photocatalytic miniralization of all of them. This study is part of an extensive project focused on the design of a solar photocatalytic plant for decontamination of agricultural rinsates in Almería (Spain).

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Heterogeneous Photocatalysis

ChemEngineering ◽

10.3390/chemengineering5020026 ◽

2021 ◽

Vol 5 (2) ◽

pp. 26

Author(s):

Mario J. Muñoz-Batista ◽

Rafael Luque

Keyword(s):

Heterogeneous Photocatalysis ◽

Chemical Processes

Heterogeneous photocatalysis is a subtype of catalysis that refers to chemical processes catalysed by a semiconductor solid under proper illumination conditions [...]

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Solar heterogeneous photocatalysis (ZnO/UV) for textile dyes removal

Environmental Quality Management ◽

10.1002/tqem.21584 ◽

2018 ◽

Vol 28 (1) ◽

pp. 65-71 ◽

Cited By ~ 1

Author(s):

Maria Marcella Medeiros Melo ◽

Elisângela Maria Rodrigues Rocha ◽

Erika Lima Silva

Keyword(s):

Heterogeneous Photocatalysis ◽

Textile Dyes ◽

Dyes Removal

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Allergen Immunotherapy: Current and Future Trends

Cells ◽

10.3390/cells11020212 ◽

2022 ◽

Vol 11 (2) ◽

pp. 212

Author(s):

Gandhi F. Pavón-Romero ◽

Maria Itzel Parra-Vargas ◽

Fernando Ramírez-Jiménez ◽

Esmeralda Melgoza-Ruiz ◽

Nancy H. Serrano-Pérez ◽

...

Keyword(s):

Adverse Reactions ◽

Allergen Immunotherapy ◽

Immunological Tolerance ◽

Chemical Processes ◽

Structural Modifications ◽

Insect Venom ◽

Cell Counts ◽

Immunological Effects ◽

Allergen Identification ◽

Disease Modifying Treatment

Allergen immunotherapy (AIT) is the sole disease-modifying treatment for allergic rhinitis; it prevents rhinitis from progressing to asthma and lowers medication use. AIT against mites, insect venom, and certain kinds of pollen is effective. The mechanism of action of AIT is based on inducing immunological tolerance characterized by increased IL-10, TGF-β, and IgG4 levels and Treg cell counts. However, AIT requires prolonged schemes of administration and is sometimes associated with adverse reactions. Over the last decade, novel forms of AIT have been developed, focused on better allergen identification, structural modifications to preserve epitopes for B or T cells, post-traductional alteration through chemical processes, and the addition of adjuvants. These modified allergens induce clinical-immunological effects similar to those mentioned above, increasing the tolerance to other related allergens but with fewer side effects. Clinical studies have shown that molecular AIT is efficient in treating grass and birch allergies. This article reviews the possibility of a new AIT to improve the treatment of allergic illness.

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Acute toxicity assessment of textile dyes and textile and dye industrial effluents using Daphnia magna bioassay

Toxicology and Industrial Health ◽

10.1177/0748233708095769 ◽

2008 ◽

Vol 24 (7) ◽

pp. 491-500 ◽

Cited By ~ 56

Author(s):

Y Verma

Keyword(s):

Acute Toxicity ◽

Daphnia Magna ◽

Aquatic Toxicity ◽

Industrial Effluents ◽

Toxicity Assessment ◽

Textile Dyes ◽

Textile Mill ◽

Golden Yellow ◽

Excellent Method ◽

High Degree

Aquatic toxicity of textile dyes and textile and dye industrial effluents were evaluated in an acute toxicity study using Daphnia magna as an aquatic experimental animal model. The 48-h EC50 value for the azo dyes, Remazol Parrot Green was 55.32 mg/L and for Remazol Golden Yellow was 46.84 mg/L. Whereas 48-h EC50 values for three dye industrial effluents (D1, D2, and D3) were 14.12%, 15.52%, and 29.69%, respectively. Similarly, EC50 value for three textile mill effluents (T1, T2, and T3) were >100%, 62.97%, and 63.04%, respectively. These results also showed linear relationship with high degree of confidence ( r2 = >0.84 to >0.99) between immobility and test concentrations. The ratio of 24 to 48-h EC50 remains to be in between 1.1 and 1.2. The general criteria of toxicity classification showed that both dyes were minor acutely toxic having 48-h EC50 in between 10 and 100 mg/L. Of the six textile and dye industrial effluents tested, one was not acutely toxic (48-h EC50 > 100%) and five were minor acutely toxic (48-h EC50 > 14.12–29.69%). The toxicity classification of effluent based on toxic unit (TU) showed that of the six effluents tested five were found toxic (TU = >1) and one was non-toxic (TU = <1). Thus, dye effluents showed highest toxicity and textile effluents lowest toxicity. The study also suggested that the assay with D. magna was an excellent method for evaluation of aquatic toxicity of dyes and dyes containing industrial effluents.

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