Current Trends in the Utilization of Photolysis and Photocatalysis Treatment Processes for the Remediation of Dye Wastewater: A Short Review (original) (raw)
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Photocatalytic degradation of dye wastewater
2020
Dye wastewater is the major environmental issue of the textile and printing industries besides other minor issues like solid waste, health and safety. The use of synthetic chemical dyes in various manufacturing industrial process has increased considerably over the past decades, resulting in the release of dye-containing industrial effluents into aquatic ecosystem and soil [1]. Wastewater from printing and dyeing industries is frequently rich in color, containing residues of toxic chemicals, reactive dyes and requires proper treatment before all the effluent release into environment [2]. There are more than 8000 chemical products associated with all the dyeing, printing and finishing process listed in the color index, including some of the structural diverse of dyes, such as basic, acidic, reactive, disperse, azo, diazo, anthraquinone based and metal-complex dyes [1]. Therefore, these wastes must be genuine treated before it discharge to environment in order to comply with the envir...
2011
Crittenden for their support and help. It would have been next to impossible to finish this thesis writing without their continual guidance and commitment. Separately, I would like to thank Vladimir who welcomed me to be a part of his research group that provided me valuable experiences of learning and research in Chemistry. He (with Professor Ian Shaw) also cared for my health and safety to work in the laboratory during my pregnancy. Thank you to NZAIDthe international agency for development of New Zealand Ministry of Foreign and Trade for the scholarship, by which I have had the experiences of studying and living here in Christchurch, New Zealand. I would especially like to thank Nick Oliver and Danny Leonard from the Mechanical Workshop, Roger Merryweather and Steven Graham from the West Precinct Electronic Workshop, as well as Robert McGregor from the Glassblowing workshop, for their excellent collaboration in constructing the photocatalytic chamber, without which the project would not have been possible. Thanks also go to Dr. Matthew Polson for the UV-Vis spectroscopy facilities. My thanks go to Jan-Yves Ruzicka and David Anderson for providing me their catalysts, Anthony and Farida who helped me during my critical times, and the other members of the Golovko group who have made my study life an enjoyable experience. Thanks separately go to Jan-Yves for his help with experimental (especially in my first months), studying, and editing the English of my thesis.
Bioengineered
Rapid industrialization has provided comforts to mankind but has also impacted the environment harmfully. There has been severe increase in the pollution due to several industries, in particular due to dye industry, which generate huge quantities of wastewater containing hazardous chemicals. Although tremendous developments have taken place for the treatment and management of such wastewater through chemical or biological processes, there is an emerging shift in the approach, with focus shifting on resource recovery from such wastewater and also their management in sustainable manner. This review article aims to present and discuss the most advanced and state-of-art technical and scientific developments about the treatment of dye industry wastewater, which include advanced oxidation process, membrane filtration technique, microbial technologies, bio-electrochemical degradation, photocatalytic degradation, etc. Among these technologies, microbial degradation seems highly promising for resource recovery and sustainability and has been discussed in detail as a promising approach. This paper also covers the challenges and future perspectives in this field.
Dyes are an important class of organic pollutants and are well known for their hazardous effects on aquatic life in general and human beings in particular. In order to reduce the negative effects of dye contaminated wastewater on humans and the environment, the wastewater must be treated carefully before discharge into main streams. Advances in science and technology have led to the evolution of several techniques for the removal of dyes from industrial and domestic effluents. In this review, the more recent methods for the removal of dyes from water and wastewater have been discussed. Wastewater treatment techniques such as adsorption, oxidation, flocculation–coagulation, membrane filtration and biological treatment have been highlighted. In addition, efforts were made to review all the available techniques and recently published studies from 2010–2014. Furthermore, the performance and special features of these technologies have been summarised. Advantages and limitations of each technique are also presented. A thorough literature survey revealed that chemical oxidation, adsorption, and biological treatments have been the most frequently investigated techniques for dye removal over the past few years.
Chemical Engineering Journal, 2009
Synthetic dyes are a major part of our life as they are found in the various products ranging from clothes to leather accessories to furniture. An unfortunate side effect of their widespread use is the fact that up to 12% of these dyes are wasted during the dyeing process, and that approximately 20% of this wastage enters the environment (mostly in water supply). Not surprisingly, various approaches have been developed to remove and degrade these carcinogenic dyes from the natural environment. Advanced oxidation processes (AOPs) are the most widely used approach that is employed for dye degradation studies. Over the past few years, there has been an enormous amount of work that has been done with AOPs and as a result various kinds of AOPs have been developed. The aim of this review is to address the fundamentals of one kind of AOP, namely, photocatalytic, and how it is used for dye degradations in aqueous suspensions using TiO 2 as a catalyst. Since AOPs rely on the generation and subsequent reaction of highly reactive oxygen radicals with dyes, there are many factors that can affect the efficiency of this process. Hence, this review will attempt to summarize and highlight the effect of a variety of conditions on TiO 2-photocatalysed decoloration of dyes, such as amount of catalyst, reaction pH, light intensity, concentration of organic dye, and the presence of additives such as ions. This review also summarizes the degradation pathways that azo dyes undergo, with some of the intermediates that are generated during their degradation. Finally, a survey is presented of the various classes of dyes and their relative ease of degradation by AOPs.
Process Development for Photocatalytic Degradation of Reactive Dyes in Wastewater
Advanced oxidation processes (AOPs) are widely used for the removal of recalcitrant organic constituents from industrial and municipal wastewater. This study mainly focused the use of TiO 2 and ZnO catalysts for removal of textile dyes. Synthesis of TiO 2 and ZnO photo catalysts was done by sol-gel method. These catalysts were used to obtain enhanced photo catalytic action and were coated on glass beads to improve the photo catalytic activity. The synthesized beads were examined using SEM, FTIR and XRD. Synthesized photocatalysts were examined extensively for their photocatalytic activities with Reactive Orange(RO), Reactive Blue(RB), Textile industry Effluent (TIE) and mixture of dyes (RO+RB, RO+RB +TIE) at various concentrations (50ppm, 100ppm). The photocatalytic degradation of RO, RB, TIE, RO+RB and RO+RB +TIE dyes solution (100mg/L and 50mg/L) using TiO 2 and ZnO were investigated under UV light irradiation (λ=254nm). Photocatalytic studies revealed that the TiO 2 has shown much higher photocatalytic activity than the ZnO catalyst. The photocatalytic activity of the TiO 2 catalyst follows the order: Reactive Orange of 50 ppm (80.98%) > Reactive Blue dye of 50 ppm (77.17%)> Reactive Orange dye of 100 ppm (74.98)>Reactive blue of 100 ppm (72%). The photocatalytic activity of the ZnO catalyst follows the order: Reactive Orange of 50 ppm (75.12%) > Reactive Blue dye of 50 ppm (73.98%)> Reactive Blue dye of 100 ppm (71%)>Reactive Orange of 100 ppm (70%).
An overview to photo-catalytic degradation of dyes in waste water
Organic dyes used in textile and food industries are the important sources of environmental contaminations due to their non-bio degradability and high toxicity to aquatic creatures and carcinogenic effects on humans. This demands environmental remediation by the use of techniques which are environmentally benign. For this purpose, a general overview of dye degradation by light in the presence of materials as photo-catalysts has been given. The mechanism of action has also been described. Importantly, the materials involved in dye degradation usually involve nano-composites of either conducting polymers or metal-oxidesor graphene based systems which are insoluble in aqueous solutions, hence will be environmentally benign and can therefore be recovered after use.
Comparison of dye wastewater treatment methods: A review
GSC Advanced Research and Reviews, 2022
Wastewater is produced by numerous dyes producing and dye consuming industries in their process activities especially the textile industry. These effluents become toxic and harmful to the living things and the environment if not properly treated before being discharged to the environment. In recent decades dye wastewater has been becomes a growing water pollution problem because it is one of the most difficult to treat. To put an end to this problem, viable, efficient, and sustainable method of treatment of dye wastewater and color removal needs to be established. Several research papers have been done over the years on various treatment method of dye wastewater with evolving options; this paper is to bring together both the conventional and new methods. Some of the conventional and new methods researched over the years include activated sludge, coagulation, adsorption, membrane separation processes and electrochemical process etc. Although there is currently no uniform standard or method of treatment universally adopted, many countries have put in place allowable limits of composition of dischargeable wastewater. This paper seeks to explore which methods are highly efficient, produces manageable and recyclable waste and a combination/hybrid treatment option of these methods to achieve maximum color removal.
The Comparison of Photocatalytic Degradation and Decolorization Processes of Dyeing Effluents
International Journal of Photoenergy, 2013
Treatment of dye effluents resulting from the industrial scale dyeing of cotton, polyacrylic fibres, leather, and flax fabrics by photocatalytic methods was investigated. Photocatalytic processes were initiated by UV-a light ( max 366 nm) and were conducted in the presence of TiO 2 , TiO 2 /FeCl 3 , or FeCl 3 as photocatalysts. It was found that the photocatalytic process carried out with TiO 2 and TiO 2 /FeCl 3 was the most effective method for decolorization of textile dyeing effluents and degradation of dyes, except for effluents containing very high concentrations of stable azo dyes. During the photocatalytic degradation of anionic dyes, a mixture of TiO 2 /FeCl 3 was more effective, while in the case of cationic dyes, more suitable seems to be TiO 2 alone. d Absorption band without any clear maximum.