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Photos illustrating color change of dye solutions and their structures: EV (a), VBB (b), RBRX-3B (c), WAGGS (d). All the dyes were added 200 μmol/L. All liquids were settled for 10 min. 1 Dye-only. 2 treated with 0.18% BaSO4-only, 3 treated with 0.18% BSD material.
Source publication
A new sorbent material, barium sulfate-Direct Blending Yellow D-3RNL hybrid (BSD), was synthesized and characterized by various methods. Both the anionic dyes, Reactive Brilliant Red X-3B and Weak Acid Green GS were hardly adsorbed by the BSD material, while the sorption of Ethyl Violet (EV) and Victoria Blue B were extremely obvious. The sorption...
Citations
... Dyes are widely used in the textile, chemical and cellulose industries, for the production of plastics, paints and varnishes. Over 10,000 different dyes and more than 700,000 tons of dyes are produced every year, and 2-50% are discharged into the aquatic environment [9,10]. Many dyes, especially those containing azo groups or aromatic rings, e.g., acid type dyes, discharged into water as a waste can causes serious danger as they are difficult to degrade [9]. ...
... Over 10,000 different dyes and more than 700,000 tons of dyes are produced every year, and 2-50% are discharged into the aquatic environment [9,10]. Many dyes, especially those containing azo groups or aromatic rings, e.g., acid type dyes, discharged into water as a waste can causes serious danger as they are difficult to degrade [9]. Moreover, some of them are mutagenic and carcinogenic [9]. ...
... Many dyes, especially those containing azo groups or aromatic rings, e.g., acid type dyes, discharged into water as a waste can causes serious danger as they are difficult to degrade [9]. Moreover, some of them are mutagenic and carcinogenic [9]. This study presents synthesis and application of the functionalized polymeric resin DVB-co-GMA-TETA for the removal of three textile dyes (C.I. ...
Intensive development of many industries, including textile, paper, plastic or food, generate huge amounts of wastewaters containing not only toxic dyes but also harmful auxiliaries such as salts, acid, bases, surfactants, oxidants, heavy metal ions. The search for effective pollutant adsorbents is a huge challenge for scientists. Synthesis of divinylbenzene copolymer with glycidyl methacrylate functionalized with triethylenetetramine (DVB-co-GMA-TETA) resin was performed and the obtained microspheres were evaluated as a potential adsorbent for acid dye removal from dyeing effluents. The sorption capacities were equal to 142.4 mg/g for C.I. Acid Green 16 (AG16), 172 mg/g for C.I. Acid Violet 1 (AV1) and 216.3 mg/g for C.I. Acid Red 18 (AR18). Non-linear fitting of the Freundlich isotherm to experimental data was confirmed rather than the Langmuir, Temkin and Dubinin-Radushkevich. The kinetic studies revealed that intraparticle diffusion is the rate-limiting step during dye adsorption. Auxiliaries such as Na2SO4 (5–25 g/L), CH3COOH (0.25–1.5 g/L) and anionic surfactant (0.1–0.5 g/L) present in the dyeing baths enhance the dye adsorption by the resin in most cases. Regeneration of DVB-co-GMA-TETA is possible using 1 M NaCl-50% v/v CH3OH.
... Annually more than 300,000 tons of dye sludge are produced, requiring adequate chemical and biological treatment processes (Xu et al., 2012). Therefore they have the potential to be harmful to human being, animals and surrounding environment without adequate treatment to reduce leaching of metal(loid)s below the regulation (Bednarik et al., 2004). ...
The applicability of solidification/stabilization (S/S) to reduce leaching potential of metal(loid)s from dye sludge char (DSC) and the suitability of the treated DSC as a landfill cover material was investigated. The dye sludge charred at 350ºC (DSC350) and 550ºC (DSC550) was solidified and stabilized by the amendment of cement, lime, ladle slag or hydroxyapatite (HAP). Leaching potential of metal(loid)s from the binder-amended DSC550 was below the Korean Standard Leaching Test (KSLT) and US EPA Toxicity Characterization Leaching Procedure (TCLP) criteria. DSC550 had higher Unconfined Compressive Strength (UCS) than DSC350 due to higher ash content and less volatile matter content. Calcium oxide and silica present in cement, lime or ladle slag enhanced the UCS of DSCs. The dose of 0.05 g cement, 0.075 g lime or 0.075 g ladle slag per g of dry DSC550, respectively was optimum to meet the UCS criteria (350 kPa), but not HAP. After blending with a natural soil, the hydraulic conductivity of the binder-amended DSC550 was higher than that of clayey soil (1 × 10⁻⁵ cm/s to 1 × 10⁻⁶ cm/s). Further study such as blending with clayey soil is needed to decrease hydraulic conductivity to 10⁻⁵ to 10⁻⁶ cm/s.
... Chemical pollution of surface water presents a threat to the aquatic environment with hazardous effects such as genotoxicity, carcinogenicity, Neurotoxicity and disturbance to the energy transfer by lowering ATP production [11]. Coloured materials and organic dyes constitute the focus of many environmental concerns because of their nonbiodegradable and polluting nature [10,12,13]. ...
The adsorption of methyl orange (MO) from its solution by steam activated coal from Morupule colliery was investigated spectrophotometrically using the batch technique, through kinetics and thermodynamics’ study, and found to be reversible at all temperatures used. This was to check whether the coal could be used to purify dye-polluted water from dying and printing textile industry. The effects of varying methyl orange concentration, solution pH and temperature were investigated. The adsorption rate and the adsorption capacity increased with increasing initial concentration, with decreasing solution pH and with increasing temperature. The adsorption capacity was generally low probably due to the low coal surface area (10 m2g-1). The increase in rate and capacity with increasing temperature is believed to be increased surface area due to the swelling of coal which accompanies its heating. The adsorption kinetics fitted the Lagergren pseudo second order model best indicating overall third order or dual simultaneous pseudo first order processes. Results from the thermodynamic study fitted Freundlich model best indicating heterogeneity of the surface of the coal sample.
... 1. In addition, the associative toxicity study is scarce though there exist some dye wastewater treatment researches (Xu et al., 2012; Wei et al., 2011). The objectives of the work were to assess the basic toxicity characteristics of dyes and characterize the proper toxicity order, and determine the relationship between the toxicity and the corresponding structure on the basis of laboratory findings. ...
... The structures of the azo dyes are given in Fig. 1. In addition, the associative toxicity study is scarce though there exist some dye wastewater treatment researches ( Xu et al., 2012;Wei et al., 2011). The objectives of the work were to assess the basic toxicity characteristics of dyes and characterize the proper toxicity order, and determine the relationship between the toxicity and the corresponding structure on the basis of laboratory findings. ...
As an interesting photocatalytic material, black TiO2 has high research and application value. Some desirable adsorption and photocatalytic composites will be fabricated in combination black TiO2 with montmorillonite (MMT). In this paper, nano-structures of TiO2/MMTs were characterized by XRD, FT-IR, Raman, XPS, PL and UV–Vis DRS. It can be concluded that the existence of MMT delays the crystal transformation of TiO2. New Ti–O–Si bonds, oxygen vacancy clustering and minimal Ti (III) contents were emerged and intensified in black TiO2/MMT. These special structures are helpful to preventing the recombination of electrons and holes which were used to degrade the dye molecules. The photocatalytic performance was determined by the decolorization ratio of two kinds of dyes under sunlight or indoor visible light. The degradation efficiencies of rhodamine B (Rh B) and methyl orange (MO) can reach 78.7% and 53.2%, respectively, after illuminated for 140 min under sunlight. The assessment of radical scavengers shows that the main functional radicals in the degradation of Rh B and MO were ·O2− and ·OH, respectively. These new catalysts have wide range of utilization in the degradation of phenols, aromatics, pesticides and antibiotics compounds.
Recently, the circular economy aiming at elimination of waste and the continual use of resources has attracted a lot of attentions. In the circular system, the resource recovery uses the recycled wastes as the raw material to manufacture new valuable products. This work focuses on a low-cost process, in which an activated carbon (AC) adsorbent was prepared from waste cation exchange resin by calcination and HNO3 activation hydrothermal method. Surface structure and chemistry of AC were characterized by SEM, XRD, FTIR and Boehm titration. It was found that the acid treatment could increase the number of pores and the content of oxygen-containing functional groups on AC surface. In the adsorption experiment, Methylene blue (MB) was used to assess the adsorption capacity of AC. Experimental results showed that the highest efficiency of MB removal was achieved by AC with modification of 4M HNO3, showing the acidification effect on the adsorption capacity of AC. Adsorption isotherms of Langmuir and Freundlich were employed to fit the experimental data. It was shown that MB adsorption on AC is more consistent with Langmuir model that assumes a homogeneous adsorption. In the adsorption kinetic analysis, the adsorption was found to follow the pseudo-second-order model, indicating that adsorption of MB on acidified AC is dominated by chemical adsorption. The study revealed that the waste ion-exchange resin is a proper precursor of carbon adsorbent for MB dye. This low-cost method would specifically reduce the environmental cost of waste disposal.
We have fabricated various catalytic and photocatalytic metal/metaloxide semiconductor nanostructured materials for environmental remediation, point-of-care diagnostics and energy storage applications. Experiments have been performed for the characterizations to study their properties on nanoscale. Further, those synthesized nanostructured materials have explored towards biosensing, wastewater treatment and supercapacitor electrodes depending on their functionalities. The synthesized nanomaterials were TiO2, SiO2, ZnO, MnO2, SnO, SnO2, Fe2O3, NiO, CVD and PECVD grown CNTs, electrospun polymer and carbon nanofibers, carbon films, graphene and carbon monoliths. Those were functionalized with desired biomolecules and integrated with biochips for real time monitoring human blood cholesterol, breast cancer biomarkers lipoprotein and triglyceride molecules via electrochemical methods. We have developed few new methods for the synthesis of metal-oxide wideband gap semiconductor catalysts by electrospinning, spin coating and micro phase separation mediated sol-gel derived processes. Carbon MEMS pattered electrodes have been fabricated using photolithography and carbon, metal and metal-oxide nanofibers were synthesized by electrospinning technique. Pure and carbon doped photocatalytic semiconductors (TiO2 and ZnO) were explored for organic wastewater purification by Uv-assisted photocatalysis technique. Porous carbon and metal-oxide carbon composites were used for supercapacitor and Li-ion battery and biosensor applications.
Industrial effluents that carry dyestuff into natural water systems are serious environmental concern. The complex aromatic structures of dyes make them more stable and more difficult to remove from the effluents discharged into water bodies. Dyes are known pollutants that not only affecting esthetic merit but also reducing light penetration and photosynthesis, and some are considered toxic and even carcinogenic for human health. This study examined the feasibility of removing reactive blue 29 dye (RB29) from aqueous solutions using multiwall carbon nanotubes (MWCNTs) and oxidized MWCNTs. The effects of RB29 dye concentration, MWCNT and MWCNT-COOH dosage, and pH on adsorption of RB29 by both MWCNTs and MWCNT-COOH were also evaluated. Also, the adsorption isotherms of this dye on to carbon nanotubes (CNTs) and related constants were studied. Results showed that adsorption capacity of pristine MWCNTs was higher than oxidized MWCNTs due to negative charge put on the surface of MWCNT-COOH. The adsorption capacities of MWCNTs and MWCNTs-COOH in the best conditions were 49 and 34 mg/g, respectively. The results also demonstrated that adsorption capacity of RB29 on CNTs was higher in lower pHs due to significantly high electrostatic attraction exists between the positively charged surface of the adsorbent and negatively charged anionic dye. And finally the Freundlich isotherm showed the best conformity to the equilibrium data.
Adsorption of Direct Blend Yellow D-3RNL in aqueous solution by activated carbons prepared from Moso timber bamboo stem residues was optimized by using central composite design matrix and response surface methodology. A maximum dye removal from the experimental validation reached 92.1% under the optimum conditions (initial dye concentration 20 mg L−1, pH 2, bamboo-based activated carbon dosage 20 g L−1, temperature 50°C, and time of adsorption 20 h) with the relative standard deviation 5.37%. The high R 2 value (0.9487) for the second-order model obtained from the analysis of variance (ANOVA) indicated that the experimental data fitted well with the predicted data. The adsorption followed the nonlinear model of pseudo-second-order reaction and agreed well with Freundlich judged by the levels of Akaike Information Criterion and Akaike weight. Furthermore, the thermodynamics analysis indicated that the adsorption was a spontaneous, endothermic, entropy-increasing, and chemisorption process.
