Decolorization Of Wastewater Research Articles

Intensification of ozone mass transfer for wastewater treatment using a rotating bar reactor

As one of the advanced oxidation processes (AOPs), ozonation has been widely used in the treatment of textile dyeing wastewater. However, ozonation was limited by the mass transfer process due to the low solubility of ozone in water. In this work, a novel rotating bar reactor (RBR) was developed to enhance ozone-water mass transfer via optimizing its inner structures. The RBR with the internal structure of sieve plates combined with spoiler columns has the best mass transfer performance, which was 249% higher than that of the RBR without these structures. Furthermore, the optimized RBR was adopted to intensify the decolorization of the simulated wastewater of reactive black 5. The ozone dose was used to characterize the introduced ozone mass for treating a liter of wastewater in different reactors. The ozone dose in RBR was 150 mg/L (using O3), which was lower than that in semibatch glass reactor (567 mg/L, using O3/UV/H2O2) and in cylindrical glass cell (506.67 mg/L, using O3/US), reported in the literatures. The results indicated that RBR can achieve the same decolorization rate with less ozone dose, i.e. the RBR is more efficient. The RBR exhibited great potential application in enhancing liquid-film controlling system.

Textile Wastewater Decolorization by Pleurotus ostreatus in Organic Material Board Media

The textile industry in one of the fastest industries that grow today. However, the increased activity makes the production of liquid wastewater also increased because the use of water reaches 80% in production. The wastewater can endanger the aquatic ecosystems because it contains toxic dyes. Pleurotus ostreatus has ligninolytic enzymes that are capable of degrading synthetic dyes into non-toxic forms to the environment. This study aims to determine the optimum contact time of P. ostreatus in organic material board media for the best result in textile wastewater decolorization. This research used an experimental method. The research consisted preparation of P. ostreatus isolate, making of seed media, inoculation into seed media, making of log media, inoculation into log media, making of board media, and decolorization process. The parameters tested were different contact time (24, 48, 72, 96, 120, 144, and 168 hours), Total Dissolved Solid (TDS), pH, and temperature. The result of this research was that the treatment of P. ostreatus in organic material board media can decolorize textile wastewater. The value of highest decolorization percentage was 35,69% at 24 hours contact time. There are change of TDS, pH, and temperature on before and after namely 835 to 566, 8.7 to 7.62, 28.3 to 31. This board system is promising for wastewater treatment.Keywords:decolorization, textile wastewater, P. ostreatus, board media

Efficient degradation of molasses wastewater from sugar mill by lipase via addition reaction

It has been observed that hydrolases such as cutinases have made significant breakthroughs and achieved good results in catalyzing the enzymatic decolorization of molasses wastewater. However, their actual application has been limited by inferior industrialization scale and other drawbacks. The aim of this research was to investigate the potential of lipase in decolorizing molasses wastewater via decolorization experiment, molecular simulations, immobilization technology, etc. It was found that lipase Lecitase Ultra achieved a maximum decolorization yield of 84.62–86.81% among all of the enzymes analyzed. Additionally, compared with cutinases and keratinases, it can be applied on a larger industrial scale. Subsequently, this work adopted a carrier-free immobilization technology and it was observed that upon combined with deep eutectic solvent, the immobilized Lecitase Ultra exhibited excellent enzymatic properties, he highest decolorization yield (58.14–60.55%) as well as other parameters among all of the immobilized enzymes. Furthermore, it only effectively eliminated 77.56% of melanoidins. The binding mode of melanoidins representative substrate to lipase was structured. The results indicated that the lipases could destroy the unsaturated system of olefins and ketones in melanoidins through catalyzing an addition reaction to achieve the effect. Thus, these findings provide a reliable approach for the decolorization of molasses wastewater.

Comparison between cotton fiber and cellulose powder for wastewater treatment efficiency with nano-crystalline TiO2 by sono-synthesis

PurposeThe main purpose of this study was to prepare the cotton fibers and cellulose powder by a layer of nano-crystalline-titanium dioxide (TiO2) using the sol-gel sono-synthesis method to clean the wastewater containing reactive dye. Moreover, TiO2 nano-materials are remarkable due to their photoactive properties and valuable applications in wastewater treatment.Design/methodology/approachIn this research, TiO2 was synthesized and deposited effectively on cotton fibers and cellulose powder using ultrasound-assisted coating. Further, tetra butyl titanate was used as a precursor to the synthesis of TiO2 nanoparticles. Reactive dye (red 195) was used in this study. X-ray Diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy were performed to prove the aptitude for the formation of crystal TiO2 on the cotton fibers and cellulose powder along with TiO2 nanoparticles as well as to analyze the chemical structure. Decoloration of the wastewater was investigated through ultraviolet (UV-Visible) light at 30 min.FindingsThe experimental results revealed that the decolorization was completed at 2.0 min with the cellulose nano TiO2 treatment whereas cotton nano TiO2 treated solution contained reactive dyestuffs even after the treatment of 2 min. This was the fastest method up to now than all reported methods for sustainable decolorization of wastewater by absorption. Furthermore, this study explored that the cellulose TiO2 nano-composite was more effective than the cotton TiO2 nano-composite of decoloration wastewater for the eco-friendly remedy.Research limitations/implicationsCotton fibers and cellulose powder with nano-TiO2, and only reactive dye (red 195) were tested.Practical implicationsWith reactive dye-containing wastewater, it seems to be easier to get rid of the dye than to retain it, especially from dyeing of yarn, fabric, apparel, and as well as other sectors where dyestuffs are used.Social implicationsThis research would help to reduce pollution in the environment as well as save energy and cost.Originality/valueDecoloration of wastewater treatment is an essential new track with nano-crystalline TiO2 to fast and efficient cleaning of reactive dyes containing wastewater used as a raw material.

Probing the performance and mechanisms of Congo red wastewater decolorization with nanoscale zero-valent iron in the continuing flow reactor

Rapid and efficient decolorization is great challenging for wastewater treatment, and nanoscale zero-valent iron (nZVI) was recognized as an environmental-friendly and economical-cost agent for effective decolorization of textile wastewater. Herein, the performance and mechanisms of Congo Red (CR) wastewater treatment with nZVI were probed in a continuous flow nano-iron reactor (NIR), which included the “reaction, separation and reuse” process. CR wastewater (initial concentration up to 500 mg·L−1) was successfully decolorized by nZVI in the NIR during the 125 d continuous running period. The color removal efficiency achieved 98.59%, accompanied with a large removal capacity of 6.64 mg-CR/g-nZVI at an average low nZVI dose (0.075 g-nZVI/L-CR). The decolorization mechanism of CR wastewater was ascribed to the chromophore groups (–N=N–) breaking, the final productive products were 4-Amino-1-naphthalene sulfonic acid and 4,4′-diaminodiphenyl, which were proved by liquid chromatography coupled to mass spectrometry, X-ray photoelectron spectroscopy, UV–Vis spectrophotometer, infrared spectroscopy. Decolorization efficiencies were up to 77.82% and 87.95% on average for two actual textile wastewater in the NIR, during the 83.5 h and 445 h continuous running period. This work provides proof that the nZVI technology can offer tremendous potential for the decolorization of recalcitrant organic dye wastewater.

Enhancing dye wastewater treatment efficiency in ozonation membrane contactors by chloro– and fluoro–organosilanes’ functionality on hydrophobic PVDF membrane modification

This work investigated the decolorization of dye wastewater using an ozonation membrane contactor. The hydrophobicity of a PVDF membrane was developed by applying novel plasma activation followed by grafting with methyltrichloroalkylsilane (PVDF–MTCS) and 1H, 1H, 2H, 2H–perfluorodecyltriethoxysilane (PVDF–FAS–C8) at different grafting times and grafting agent concentrations. After hydrophobic membrane modifications, the ozonation membrane performances were improved. The ozone flux of PVDF–FAS–C8 was higher and more stable, maintaining 88% of the initial flux after 20 h, compared to 79% and 53% for the PVDF − MTCS and original membranes, respectively. After 90 mins, COD removals of Direct Blue 71 (DB 71) and Reactive Red 239 (RR 239) by the ozonation membrane contactor using PVDF–FAS–C8 were 62.5% and 67.5%, and TOC removals were 20% and 23%, respectively, with almost complete decolorization. The releases of sulfate and nitrate ions confirmed the dye mineralization. By applying a PVDF − FAS − C8 membrane, energy consumption was 33.2% lower than when using the original membrane. The findings exhibited that the performance of ozonation membrane contactor improved was due to the role of the functionality on modified PVDF membranes. The PVDF − MTCS membrane had a higher silicon composition and better surface roughness than the PVDF − FAS − C8 membrane. The water contact angle (WCA) of the PVDF − MTCS membrane was higher than that of the PVDF − FAS − C8 membrane, increasing from 74.7°(original) to 126.0° and 112.7°, respectively, after 6 h of grafting, leading to reduced membrane wetting.

A New Report of Rhodamine B Contaminated Wastewater Decolorization and Electricity Generation by Laccase Based Microbial Fuel Cell

Rhodamine B (RB) is a basic color for natural plant textile dyeing. This study aims to use the laccase and manganese peroxidase-producing consortium to degrade the RB and generate electrical energy in a novel model microbial fuel cell (MFC). The results revealed that the MFC with consortium KJW40 had current densities and power densities of 4,816.6728.87 mA/m3, and 2,320.0827.86 mW/m3, respectively. The RB removal rate was 80.560.13 % was reached. This work gained new knowledge about using a bacterial consortium producing laccase and manganese peroxidase to treat contaminated RB and generate electrical power.

Optimization studies on decolorization of textile wastewater using natural coagulants

The textile industry produces large amounts of wastewater from various finishing and dyeing processes. The eco-friendly coagulants which are readily available and low-cost, can be chosen as an alternative to other conventional coagulation methods. A study on the removal of commercially used dye from textile wastewater was conducted to investigate the effectiveness of coagulation with natural coagulants. Natural coagulants can treat low to high turbid water and have remarkable color removal efficiency that can be used for various purposes. Four types of Natural coagulants, viz Maize, Green beans, Nirmal seeds (Strychnos potatorum), and Moringa seeds, were studied. Moringa seeds were the promising coagulant for color removal from textile wastewater. Further, the process parameters like coagulant concentration, pH, and mixing time to decolorize textile wastewater were optimized using Response surface methodology (RSM). The optimum conditions from RSM for the maximum decolorization were obtained at coagulant concentration 55 mg/L, pH 6.5, and mixing time 62.5 min. At these optimum conditions, maximum decolorization obtained 98.7%, TDS-312 ppm & Turbidity-3 NTU. The decolorization of the textile wastewater using natural coagulants was best described by a second-order polynomial equation with a correlation coefficient R2 of 0.9868.

Decolorization of textile wastewater by electrooxidation process using different anode materials: Statistical optimization.

The presence of reactive dyes in textile wastewater is a serious environmental concern due to their associated mutagenic and carcinogenic effects. The present study aims to analyze the effect of different anodic materials on the decolorization of a real textile wastewater effluent. For this purpose, four different anodic materials-TiO2 -coated platine, TiO2 -coated ruthenium dioxide (RuO2 ) (viz., RuO2 ), titanium dioxide (TiO2 ), and graphite-were connected, respectively, to titanium dioxide (TiO2 ) used as a cathode electrode. Color and cost optimization studies were performed using the response surface methodology and the Box-Behnken experimental design (BBD). According to ANOVA results, the R2 values for Pt/TiO2 , RuO2 /TiO2 , TiO2 /TiO2 , and graphite/TiO2 electrode pairs were found to be 97.4%, 93.8%, 92.44%, and 92.2%, respectively, indicating a good compatibility as it is close to one. The results show that color removal efficiencies at the optimal conditions were 86.3%, 90.8%, 91.5%, and 93.6% for Pt/TiO2 , graphite/TiO2 , TiO2 /TiO2 , and RuO2 /TiO2 , respectively. Furthermore, energy consumption cost at the optimum conditions was also evaluated, and the results were as follows: Pt/TiO2 (0.95 €/m3 ), graphite/TiO2 (0.74 €/m3 ), TiO2 /TiO2 (0.31 €/m3 ), and RuO2 /TiO2 (0.26 €/m3 ). Consequently, this research paper shows that all of the tested anodic materials give satisfactory color removal efficiencies higher than 86%. When energy consumption and color removal are considered together, the use of TiO2 /TiO2 and RuO2 /TiO2 pairs would be preferred. PRACTITIONER POINTS: Anodic contribution was investigated for decolorization of textile wastewater by electrooxidation process. Graphite, TiO2 -coated Pt, TiO2 -coated RuO2 , and TiO2 were used as anode materials. Highest color removal with lowest energy consumption was achieved with TiO2 -coated RuO2 anode material (93.6%).

Artificial Intelligence-Based Tools for Process Optimization: Case Study—Bromocresol Green Decolorization with Active Carbon

This study highlights the benefits of optimizing the decolorization of bromocresol green (a colorant/pH indicator widely used in the industry, whose degradation produces toxic byproducts) by adsorption on active carbon. A set of experiments were planned and performed based on the design of experiments methodology for the following parameters: the colorant concentration (0.009-0.045 g/L), the amount of adsorbent (0.5-3 g/L), and the contact time (60-240 min). Modeling and optimization strategies were employed to determine the working conditions leading to efficiency maximization. Using the response surface methodology, the optimum values of the primary process parameters were established. In addition, a modified bacterial foraging optimization algorithm was applied as an alternative optimizer in combination with artificial neural networks in order to determine multiple combinations of parameters that can lead to maximum process efficiency. Different solutions were obtained with the considered strategies, and the maximum efficiency obtained was >99%. The study emphasizes that adsorption on active carbon is an effective method for bromocresol green decolorization in wastewater that can be further improved using advanced optimization methods.

Degradation of dye containing in textile wastewater by sequential process: photocatalytic and biological treatment.

In this research, a combined photocatalytic and biological treatment is proposed for the elimination of pollutants present in textile wastewater using a natural erionite zeolite (PE) and aluminum oxide (PA) synthesized by the sol-gel method as photocatalysts, and solar radiation. Both catalysts were characterized by XRD, SEM, and EDS. For biological treatment two bacterial consortium were used: BC1 (Escherichia coli N16, Serratia k120, Pseudomonas putida B03 and Enterobacter hormaechei), and consortium BC2 (Escherichia coli N16, Serratia Mc107, Enterobacter N9, Enterobacter hormaechei Mc9). The photocatalytic and microbiological treatments were carried out initially separately and subsequently in a sequential manner, first the photocatalytic followed by the microbiological to determine if a synergistic effect was achieved. Comparing the photocatalytic performance, erionite showed higher performance of dyes degradation (54.75%) than alumina (28.62%). While in the biological process, BC1 decreased the dye concentration to 56.93% and BC2 to 53.56%. Finally, the best combined process was PA+BC1 reaching pollutants degradation 64.62%, showing that the application of both processes promotes a decolorization in textile wastewater. The water resulting from the combined photocatalysis-microbiological degradation processes was tested for toxicity using Daphnia magna, obtaining that none of the effluents shows toxicity.

A light-switch for efficient decolorization of azo dye wastewater based on bacteria–semiconductor interaction

This study investigated the interaction of Shewanella oneidensis MR-1 and CdS in azo dye decolorization, showing that CdS could act as a light-switch to achieve fast light-driven decolorization.

Studies on decolorization of dye wastewater in down flow jet loop sparged reactor using response surface methodology

Studies on decolorization of dye wastewater in down flow jet loop sparged reactor using response surface methodology

Performance evaluation of multi-walled carbon nanotubes for decolorization of synthetic industrial wastewater: equilibrium, kinetics, and thermodynamics⁎

Performance evaluation of multi-walled carbon nanotubes for decolorization of synthetic industrial wastewater: equilibrium, kinetics, and thermodynamics⁎

Green iron particles in textile and dyebath wastewater decolorization

Green iron particles in textile and dyebath wastewater decolorization

Design and Engineering of an Efficient Peroxidase Using Myoglobin for Dye Decolorization and Lignin Bioconversion.

The treatment of environmental pollutants such as synthetic dyes and lignin has received much attention, especially for biotechnological treatments using both native and artificial metalloenzymes. In this study, we designed and engineered an efficient peroxidase using the O2 carrier myoglobin (Mb) as a protein scaffold by four mutations (F43Y/T67R/P88W/F138W), which combines the key structural features of natural peroxidases such as the presence of a conserved His-Arg pair and Tyr/Trp residues close to the heme active center. Kinetic studies revealed that the quadruple mutant exhibits considerably enhanced peroxidase activity, with the catalytic efficiency (kcat/Km) comparable to that of the most efficient natural enzyme, horseradish peroxidase (HRP). Moreover, the designed enzyme can effectively decolorize a variety of synthetic organic dyes and catalyze the bioconversion of lignin, such as Kraft lignin and a model compound, guaiacylglycerol-β-guaiacyl ether (GGE). As analyzed by HPLC and ESI-MS, we identified several bioconversion products of GGE, as produced via bond cleavage followed by dimerization or trimerization, which illustrates the mechanism for lignin bioconversion. This study indicates that the designed enzyme could be exploited for the decolorization of textile wastewater contaminated with various dyes, as well as for the bioconversion of lignin to produce more value-added products.

Removal of both anionic and cationic dyes from wastewater using pH-responsive adsorbents of L-lysine molecular-grafted cellulose porous foams

High adsorption efficiency, active to both anionic and cationic dyes and simple desorption are three main challenges of the existed adsorbents for decolorization of the dye-contained wastewaters. Porous foams based on L-lysine (Lys) molecular-grafted cellulose were firstly designed and fabricated to overcome those challenges. Cellulose were grafted with Lys in 1-butyl-3-methylimidazolium chloride (BMIMCl) via a chemical connection resulted from glycidyl methacrylate (GMA). The synthesized cellulose derivative (Cell-g-PGMA-Lys) was regenerated in the morphology of foam by non-solvent induced phase inversion from the BMIMCl-based solutions. The presence of Lys moieties and porous structure of Cell-g-PGMA-Lys were confirmed with a series of instrumental analysis. Both anionic reactive brilliant red X-3B (RBR X-3B) and cationic methylene blue (MB) were effectively adsorbed on and desorbed from Cell-g-PGMA-Lys by adjusting the solution pH value. Cell-g-PGMA-Lys had higher adsorption capacities than most of the reported adsorbents and was easy to separate from the decolorized water. It could be reused many times with little reduction of the adsorption capacity, which remained 86.9% and 92.5% for RBR X-3B and MB respectively after six adsorption-desorption cycles. The isothermal and kinetic adsorption proved that dyes were adsorbed single-layered on Cell-g-PGMA-Lys depending upon the electrostatic interaction between adsorbent and adsorbate.

Decolorization of industrial wastewater using electrochemical peroxidation process

In this study, decolorization of wastewater samples taken from the paper industry is investigated using electrochemical peroxidation process. The electrochemical peroxidation process is a part of electrochemical advanced oxidation processes, which is based on the Fenton’s chemical reaction, provided by addition of external H2O2 into reaction cell. In this study, iron is used as anode and graphite as cathode put at the fixed distance of 30 mm in a glass reaction cell. The cell was filled with the solution containing wastewater and sodium chloride as the supporting electrolyte. Factors of the process such as pH, current intensity, hydrogen peroxide concentration, and time of treatment were studied. The results illustrate that all these parameters affect efficiencies of dye removal and chemical oxygen demand (COD) reducing. The maximal removal of wastewater contaminants was achieved under acid (pH 3) condition, with the applied current of 1 A, and hydrogen peroxide concentration of 0.033 M. At these conditions, decolorization process efficiency reached 100 and 83 % of COD removal after 40 minutes of wastewater sample treatment. In addition, the electrical energy consumption for wastewater treatment by electrochemical peroxidation is calculated, showing increase as the current intensity of treatment process was increased. The obtained results suggest that electrochemical peroxidation process can be used for removing dye compounds and chemical oxygen demand (COD) from industrial wastewaters with high removal efficiency.

Synthesis of ternary-based visible light nano-photocatalyst for decontamination of organic dyes-loaded wastewater

The release of dyes-loaded wastewater from various industries is a major threat to human beings due to their health hazard effects. Ternary ferrites-based visible light photocatalyst Fe2Zn0.5Cu0.5 O4-CM (CZF-CM) was formed via the co-precipitation method. These prepared ternary ferrites nanoparticles Fe2Zn0.5Cu0.5O4 (CZF-NPs) and photocatalyst (CZF-CM) were analyzed using different spectroscopic techniques. The average crystallite size of CZF-NPs was calculated from XRD data using Scherer's equation and found to be 12 nm. The elemental composition of the synthesized ternary ferrites nanoparticles (CZF-NPs) was defined by the EDX images. The morphology of CZF-CM photocatalyst is spherical, having a smooth surface and average microspheres size of 810 μm based on SEM micrographs. The photocatalyst has bandgap of 2.57 eV, which lies in the visible range of the electromagnetic spectrum derived by extrapolating Tauc's plot. Photocatalyst CZF-CM showed 94% degradation efficiency for Rhodamine B (RB) dye at optimized conditions of initial dye concentration, catalyst dosage, pH and sunlight irradiation contact time as 40 ppm, 0.7 g, pH 8 and 125 min, respectively. Maximum degradation (96%) of methyl orange (MO) dye occurred at pH 6, at similar optimized conditions as the RB dye. The binary ferrites photocatalyst Fe2CuO4-CM (CF-CM) and Fe2ZnO4-CM (ZF-CM) of the selected metals showed lesser photocatalytic efficiency than ternary ferrites. An artificial neural network in addition to the response surface methodology was used for the optimization process. The artificial neural network is highly in agreement with the experimental results obtained for the selected dyes. The corresponding predicted response for each data set from ANOVA showed high R2, R2adj, and R2pred values for the proposed model. It also indicates that contributing parameters in the model are significant due to having very high F-values and low p-values. It is concluded that the synthesized photocatalysts are considered an efficient entrant for the decolorization of industrial wastewater.

Characterization and potential of two different anaerobic mixed microflora for bioenergy recovery and decolorization of textile wastewater: Effect of C/N ratio, dye concentration and pH

A series of standardized activity experiments were conducted to investigate the effect of the C/N ratio, dye concentration, and pH on the performance of two mesophilic mixed cultures for bioenergy production and decolorization of textile wastewater. The results showed that the most significant factor was the C/N ratio with LogWorth value of 9.961. The maximum methane yield reached 13.18 ± 0.64 mmoL/g COD with chemical oxygen demand (COD) degradation and decolorization of 84.32 and 98%, respectively under digested sludge. The propionate and butyric acid/acetic acid ratio were significantly affected by C/N ratio and the results of C/N ratio were explained by changes in the soluble by-products. The dye concentration of 100 mg/L yielded the highest biogas production with a maximum decolorization percentage. The digested sludge showed better performance under all tested conditions compared to granular sludge. Analysis of the data showed that the best condition was observed and the bioreaction was optimized.