Textile industries are responsible for one of the major environmental pollution problems in the world, because they release undesirable dye effluents. Textile wastewater contains dyes mixed with various contaminants at a variety of ranges. Therefore, environmental legislation commonly obligates textile factories to treat these effluents before discharge into the receiving watercourses. The treatment efficiency of any pilot-scale study can be examined by feeding the system either with real textile effluents or with artificial wastewater having characteristics, which match typical textile factory discharges. This paper presents a critical review of the currently available literature regarding typical and real characteristics of the textile effluents, and also constituents including chemicals used for preparing simulated textile wastewater containing dye, as well as the treatments applied for treating the prepared effluents. This review collects the scattered information relating to artificial textile wastewater constituents and organises it to help researchers who are required to prepare synthetic wastewater. These ingredients are also evaluated based on the typical characteristics of textile wastewater, and special constituents to simulate these characteristics are recommended. The processes carried out during textile manufacturing and the chemicals corresponding to each process are also discussed.

https://link.springer.com/content/pdf/10.1007/s13762-018-2130-z.pdf

Textile dye wastewater characteristics and constituents of synthetic effluents : a critical review

One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i) dyes; (ii) heavy metals; (iii) phenols; (iv) pesticides and (v) pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called "green adsorption". Under this term, it is meant the low-cost materials originated from: (i) agricultural sources and by-products (fruits, vegetables, foods); (ii) agricultural residues and wastes; (iii) low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources). These "green adsorbents" are expected to be inferior (regarding their adsorption capacity) to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc.), but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful) topics such as: (i) adsorption capacity; (ii) kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes) and (iii) critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry) with economic analysis and perspectives of the use of green adsorbents.

Green Adsorbents for Wastewaters: A Critical Review.

The utilization of leaf-based adsorbents for dyes removal: A review

Phytoremediation of textile dyes and effluents: Current scenario and future prospects

Bioremediation is an inventive and optimistic technology which is applicable for the retrieval and reduction of heavy metals in water and polluted lands. Microorganism plays an essential part in bioremediation of heavy metals. By using genetic engineering, genetically modified organisms can be generated which can likely reduce different types of polycyclichydrocarbons (PAHs). Flavobacterium, Pseudomonas, Bacillus, Arthrobacter, Corynebacterium, Methosinus, Rhodococcus, Mycobacterium, Stereum hirsutum, Nocardia, Methanogens, Aspergilus niger, Pleurotus ostreatus, Rhizopus arrhizus, Azotobacter, Alcaligenes, Phormidium valderium, Ganoderma applantus are some microbial species that help in bioremediation of heavy metals. This review not only discussed about the importance of microbes for bioremediation of heavy metals but also discussed about the challenges and limitations of native and engineered bacteria for bioremediation. Significance of bioremediation with the help of genetically engineered bacteria is in light because of its eco-friendly nature and minimum health hazards other than the physio-chemical dependent strategies, which are less eco friendly and dangerous to life.

Bioremediation of heavy metals by microbial process

In the present investigation bioaccumulation studies were performed for the removal of Methylene Blue dye from an aqueous solution using live Lemna minor. The effect of various parameters such as the biosorbent dosage (1–3 g), pH (3-8) and initial dye concentration (2–10 mg L−1) were studied. The maximum uptake capacity of the Methylene Blue using L. minor was observed as 10.93 mg g−1 at a biosorbent dosage of 1 g/300 mL, at pH 7 and at 10 mg L−1 initial dye concentration. The surface morphology was analyzed using Scanning Electron Micrograph (SEM) for analyzing micro and macropores present on the surface of the plant and the functional groups on the biosorbent were analyzed using Fourier transform infrared analyzer (FTIR) for increasing the electrostatic attraction between the plant surface and the dye molecules by adjusting the pH of the solution. Equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherm models. The Freundlich adsorption isotherm was found to be fitted well. The ef...

Accumulation of Methylene Blue Dye by Growing Lemna minor

This paper presents a comprehensive study on the effect of citric acid, sodium benzoate, sodium salicylate, and urea (hydrotropes) on the solubility and mass-transfer coefficient for the extraction of butyl acetate in water. The influence of a wide range of hydrotrope concentrations (0-3.0 mol/L) and different temperatures (303 K to 333 K) on the solubility of butyl acetate has been studied. The influence of different hydrotrope concentrations on the mass-transfer coefficient for the butyl acetate +water system has been ascertained. The Setschenow constant, K s , a measure of the effectiveness of hydrotrope, has been determined for each case. The solubility of butyl acetate increases with increase in hydrotrope concentration and also with temperature. Consequent to the increase in the solubility of butyl acetate, the mass-transfer coefficient was also found to increase with increase in hydrotrope concentration. A minimum hydrotrope concentration was found essential to show a significant increase in the solubility and mass-transfer coefficient for the butyl acetate + water system. The enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope, is reported for both solubility and mass-transfer coefficient.

Effect of hydrotropes on solubility and mass-transfer coefficient of butyl acetate

Deinococcus radiodurans is the most radiation-tolerant organism ever known. It has gained importance in recent years as a potential candidate for bioremediation of heavy metals, especially the radioactive type. This study investigates the efficiency of a recombinant D. radiodurans (DR1-bf+) strain with an ability to form biofilm for uranium remediation. The modified Arsenazo III dye method was used to estimate the uranium concentration. Uranyl nitrate aqueous solution was generated during the operation of nuclear fuel reprocessing. The D. radiodurans biofilm (DR1-bf+) grown in the presence of 20 mM Ca2+ showed remarkable ability of uranyl ion removal. DR1-bf+ (Ca2+) biofilm removed ~75+/-2% of 1000 mg/L uranium within 30 min post-treatment from uranyl nitrate aqueous solution. Uranium removal rate was also found to be directly proportional to biofilm age. This study discusses the ability of D. radiodurans biofilm in uranium removal.

A new uranium bioremediation approach using radio-tolerant Deinococcus radiodurans biofilm

Kinetic modelling of the uranium biosorption by Deinococcus radiodurans biofilm.

Experimental studies and biosorption kinetics of an intraparticle diffusion model for acid dye removal using a musa spp. waste sorbent were carried out to find the removal effects and dynamics of various operating parameters, such as initial dye concentration, sorbent dosage, pH and temperature. Experimental data were modeled with kinetic models and two biosorption isotherms of intraparticle diffusion models as well as the physiochemical data of sorbents characterized by SEM and FT-IR. Kinetic studies showed that the sorption process follows second-order rate kinetics with an average rate constant of 0.0018675 (g/mg·min). Thermodynamic parameters such as entropy of biosorption (ΔS0), enthalpy of biosorption (ΔH0) and Gibbs free energy of biosorption (ΔG0) were obtained and analyzed. Sorbent, musa spp. waste (banana peel) was characterized by FTIR and SEM. The results showed that musa spp. waste can be considered as potential sorbent for the sorption of acid violet 54 from dilute aqueous solution.

/pdf/removal-of-acid-dye-violet-54-and-adsorption-kinetics-model-3f6qit32a6.pdf

M. Dharmendira Kumar

Papers

Accumulation of Methylene Blue Dye by Growing Lemna minor

Effect of hydrotropes on solubility and mass-transfer coefficient of butyl acetate

A new uranium bioremediation approach using radio-tolerant Deinococcus radiodurans biofilm

Kinetic modelling of the uranium biosorption by Deinococcus radiodurans biofilm.

Removal of acid dye (violet 54) and adsorption kinetics model of using musa spp. waste: A low-cost natural sorbent material