Industrial Dye Wastewater Research Articles

Treatment of wastewater containing methyl orange dye by fluidized three dimensional electrochemical oxidation process integrated with chemical oxidation and adsorption

The integrated high-efficiency treatment technology for dye industry wastewater is one of the current research hot topic in industrial wastewater treatment area. This article reports a new fluidized three-dimensional electrochemical treatment process integrating activated carbon adsorption, direct electro-oxidation and ·OH oxidation. In the process, activated carbon is polarized in a fluidized bed electrochemical reactor to enhance the direct electro-oxidation and ·OH oxidation, and there is a synergistic effect of effective adsorption and electrochemical oxidation to strengthen the treatment efficiency. When 200 mg/L methyl orange is processed, its removal rate reaches 99.9% in 30min, and the synergistic efficiency is 57.3%. After 8 cycles of activated carbon reusage in the process, the removal rate of methyl orange still kept at 89.2%. It is also founded that the activated carbon maintains 64.5% of its original adsorption capacity during the cycle. These results shows its interesting application potential in the fields of high-efficiency, low-cost and green treatment of various industrial organic wastewaters. Further improvements should focus on the development of continuous operation model and the improvement of the activated carbon electro-catalytic performance and the practical regeneration ways of the activated carbon particle electrodes.

Cellulose nanofibrils/polyvinyl alcohol/silver nanoparticles composite hydrogel: Preparation and its catalyst degradation performance of cationic dye

AbstractMetal nanoparticles play an essential role in catalyzing the degradation of dyes in industrial wastewater. In order to improve the catalytic reduction and discoloration performance of silver nanoparticles (Ag NPs) to cationic dyes and facilitate recovery, we report an improved method to prepare cellulose nanofibrils/polyvinyl alcohol (CNF/PVA) porous composite hydrogel and use it to support metal nanoparticles. Silver ions were reduced to Ag NPs by the in situ reduction method after being adsorbed on the surface of the hydrogel by electrostatic adsorption, and the maximum adsorption capacity was about 136.4 mg/g. The obtained CNF/PVA/Ag NPs (CPA) composite hydrogel was characterized by scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and energy dispersive spectroscopy. Furthermore, we demonstrate the efficient utilization of composite hydrogel as a container in the discoloration of methylene blue (cationic dye) and methyl orange (cationic dye) in the presence of NaBH4. The hydrogel was quickly recovered and reused without a decrease in activity for five cycles. It showed fantastic potential in water resources protection and catalytic application.

Synthesis and Characterization of High-Purity Mesoporous Alumina with Excellent Adsorption Capacity for Congo Red.

We explore a more concise process for the preparation of high-purity alumina and to address the problem of some conventional micro- and nano-adsorbents having difficulty in exposing their adsorption sites to target pollutants in solution due to the heavy aggregation of the adsorbent, which confers poor adsorption properties. The methods of using gamma-phase high-purity mesoporous alumina (HPMA), with its excellent adsorption properties and high adsorption rates of Congo Red, and of using lower-cost industrial aluminum hydroxide by direct aging and ammonium salt substitution were successfully employed. The results showed that the purity of HPMA was as high as 99.9661% and the total removal rate of impurities was 98.87%, a consequence of achieving a large specific surface area of 312.43 m2 g−1, a pore volume of 0.55 cm3 g−1, and an average pore diameter of 3.8 nm. The adsorption process was carried out at 25 °C, the concentration of Congo Red (CR) dye was fixed at 250 mg L−1 and the amount of adsorbent used was 100 mg. The HPMA sample exhibited an extremely fast adsorption rate in the first 10 min, with adsorption amounts up to 476.34 mg g−1 and adsorption efficiencies of 96.27%. The adsorption equilibrium was reached in about 60 min, at which time the adsorbed amount was 492.19 mg g−1 and the dye removal rate was as high as 98.44%. One-hundred milligrams of adsorbent were weighed and dispersed in 200-mL CR solutions with mass concentrations ranging from 50–1750 mg L−1 to study the adsorption isotherms. This revealed that the saturation adsorption capacity of the produced HPMA was 1984.64 mg g−1. Furthermore, the process of adsorbing Congo Red in the synthesized product was consistent with a pseudo-second order model and the Langmiur model. It is expected that this method of producing HPMA will provide a productive, easy and efficient means of treating toxic dyes in industrial wastewater.

Comparative study on photocatalytic degradation of methylene blue using pristine ZnO and Ni/ZnO composite films

Industrial dye wastewater is rich in organic molecules that are harmful to all types of living organisms. The present work investigates the potential of the incorporation of Ni nanoparticles into ZnO films in order to enhance the photocatalytic degradation performance. Pristine ZnO has been widely used as a photocatalyst in a photocatalytic degradation treatment of wastewater, however can only be activated by UV light. Incorporation of Ni into ZnO can broaden the light spectrum by using both visible light and UV for the reaction, therefore enhancing the degradation efficiency. The experimental runs were performed to evaluate the effect of incorporation of Ni nanoparticles into ZnO films and morphology of Ni nanoparticles (rod-cubic-like and chain-like shapes) on the photocatalytic degradation efficiency. In this study, methylene blue was used as a model wastewater. The results revealed that addition of Ni enhanced the degradation efficiency to 44% (rod-cubic-like) and 40% (chain-like), compared to that of pristine ZnO of 33%.

Synthesis of titanates for photomineralization of industrial wastewater and organic pollutants

The optical parameters of tunnel type titanates NaTO, PdTO and Ag/PdTO were studied and they were used as photocatalysts for the photomineralization of various organic dye pollutants and industrial wastewater (IWW) under visible light irradiation.

Charged modified tight ceramic ultrafiltration membranes for treatment of cationic dye wastewater

Tight ceramic ultrafiltration membranes have been proven to exhibit good rejection performance for reactive dye wastewater at high temperatures because of their high thermal and chemical resistance. However, the application of ceramic membranes for the treatment of cationic dye wastewater is challenging because of their surface charge. In this study, a ceramic membrane is modified by grafting aminosilane (KH-551) to enhance the positive charge of the membrane surface. The rejection performance of the charged modified ceramic membrane toward the methylene blue solution is significantly improved. The modification substance is bonded to the ceramic membrane surface via covalent bonding, which imparts good thermal stability. The modified ceramic membrane exhibits stable separation performance toward the methylene blue solution. Overall, this study provides valuable guidance for the adjustment of the ceramic membrane surface charge for treating industrial cationic dye wastewater.

Persulfate-enhanced lanthanum iron oxide-mediated photocatalysis can effectively degrade an aqueous industrial dye and mineralize water and wastewater

Persulfate-enhanced lanthanum iron oxide-mediated photocatalysis can effectively degrade an aqueous industrial dye and mineralize water and wastewater

Enhancing solar photocatalytic activity of Bi5O7I photocatalyst with activated carbon heterojunction

Passive solar photocatalysis is one of the most efficient ways for the treatment of dye industry wastewater. Some dyes such as methyl orange are recalcitrant to photolysis; therefore, photocatalysts are used to expedite their degradation. Photocatalysts are semiconductors, and their activity can be improved by creating heterojunctions. In the current work, an active photocatalyst, Bi5O7I, was modified with activated carbon (AC), obtained by controlled carbonization of pistachio shells, to give xAC-Bi5O7I photocatalysts. AC loading improved the surface area of the catalyst and decreased its bandgap to 1.8 eV, making it suitable for use as a visible light photocatalyst. Activated carbon enhances adsorption, while Bi5O7I scavenges adsorbed molecules increasing the efficiency. 5AC-Bi5O7I catalyst containing 5% activated carbon displayed the optimum photocatalytic activity, which was 3.4-fold higher than that of pristine Bi5O7I. 5AC-Bi5O7I achieved 99.9 % reduction in the concentration of methyl orange in 80 min under sunlight irradiation. 5% AC-Bi5O7I is more efficient than commercial Degussa P25 photocatalyst as well. The methyl orange degradation efficiency of the catalysts studied was: 5AC-Bi5O7I > Bi5O7I > Degussa P25.

Preparation, characterization and photocatalytic activity studies of C- and N- doped CoSb2O6

Designing a novel photocatalyst for the degradation of persistent dyes in water is of immense significance considering the harmful impacts of untreated textile and dye industry waste water. Bulk scale treatment requires simple and low-cost installation methods with good efficiency and Photocatalysis offers a promising solution. This paper presents a dependable design of a photocatalyst for the treatment of dye-contaminated water. Nitrogen and Carbon doped CoSb2O6 are prepared for improved photoresponse and photocatalytic activity. The paper briefs synthesis of the oxygen-deficient parent CoSb2O6 catalyst by metathesis method, followed by doping with nitrogen and carbon, characterization by XRD, UV–Vis DRS, XPS, SEM-EDX, and the performance of as-prepared samples for photodegradation of Rhodamine B (RhB) dye. The scavenger experiments were carried out to establish the active species involved in the decomposition of Rh B. Interestingly, the doped samples have shown remarkable photodegradation activities of up to 99% in 120 mins under visible light irradiation.

Highly efficient solar evaporator based on Graphene/MoO3-x coated porous nickel for water purification

• An evaporator with Ni-G-MoO 3-x was applied for solar steam generation. • The solar evaporator has 96.0% solar absorptance. • The energy conversion efficiency can reach at 95.0% under one sun. • The evaporator shows great performance toward water evaporation. Solar water evaporation is a promising method for water purification. However, the current photothermal conversion efficiency requires further improvement. Herein, a novel structure (Ni-G-MoO 3-x ) consisting of graphene (G) and MoO 3-x coated porous nickel (Ni) is developed by combining facile chemical vapor deposition (CVD) with hydrothermal methods. The optical absorption and photothermal conversion efficiency of the materials were improved by oxygen vacancies (OVs). The as-prepared solar evaporator exhibits excellent light absorption (96%), good wettability and high conversion efficiency (95%) under 1 sun illumination. In particular, the super hydrophilicity of the evaporator can spontaneously transfer the surface salt back to the bulk seawater in the dark conditions. As a result, a stable evaporation rate can be achieved with the self-driven salt-resistant material in the evaporation cycle of more than three days. Furthermore, the evaporator has an excellent desalination ability and can extract fresh water resources from a variety of water sources (seawater, industrial waste water and organic dye wastewater) through light-to-heat conversion water evaporation technology. This work provides a fundamental guidance and insights on practical applications, thus helping to develop a highly efficient solar evaporator for clean water production.

Rapid and selective adsorption capacity towards cationic dye with an anionic functionalized Anderson-type polyoxometalate

The treatment of organic dyes in industrial wastewater has been attracted much attentions in environmental protection and health. In this work, an organic-functionalized Anderson-type polyoxometalate (POM, noted as (TBA)3POM-1) was selected to explore its conductivity and photoelectrochemical property and the application of the organic dyes adsorption. (TBA)3POM-1 showed a good conductivity and the typical characteristic of an n-type semiconductor with the band gap at 2.87 eV. The negative-charged (TBA)3POM-1 exhibits an efficient adsorption for the cationic dye MB (methyl blue), and the obvious excluding effect for the anionic dye MO (methyl orange), indicating an excellent charge-based selective adsorption capacity. (TBA)3POM-1 could be applied in a filtering apparatus for the rapid and consecutive adsorption.

Reductive photocatalytic degradation of toxic aniline blue dye using green synthesized banyan aerial root extract derived silver nanoparticles

Herein we are reporting the reductive degradation of aniline blue dye using banyan aerial root extract derived silver nanoparticles (B-AgNPs) as catalyst. We have synthesized B-AgNPs by green root method. The characterization of synthesized B-AgNPs was done using HR-TEM, UV–vis spectral, Total Organic Carbon, FT-IR and XRD techniques. The SPR band was obtained around 445 nm. Crystal structure of B-AgNPs was observed using XRD pattern. The stability of 25.6 nm sized B-AgNPs was found to be beyond four months. Finally, the synthesized B-AgNPs was applied as a photocatalytic degradation catalyst of aniline blue dye with NaBH 4 as a reducing agent. The catalytic activity was systematically monitored using UV–Visible spectrophotometry. The catalytic efficiency was calculated to be 91.76%. Moreover, the synthesized B-AgNPs were used as a catalyst for the efficient degradation of dye effluent in the dye industry. We have applied the synthesized B-AgNPs as a catalyst for the effective degradation of industrial dye wastewater. Moreover, we have proposed the possible degradation mechanism. • A facile synthesize of AgNPs using banyan aerial root extract by green method. • B-AgNPs was used as photocatalyst for the degradation of toxic aniline blue dye. • The degradation mechanism was well discussed. • B-AgNPs was applied for the degradation of aniline blue dye containing industrial effluent water.

Treatability of Wastewater Containing Reactive Yellow 145 Dyestuff by Ozonation Process

When the textile industry wastewater volume and considering the composition appears to be one of the most environmentally hazardous industries. Due to the basic properties of textile dyeing industry wastewater, additional precaution are required besides conventional wastewater treatment to remove color. The most basic approach is to remove the color of the wastewater and to break down the chromophores and double bonds that make up the color by oxidative means. In this study, the treatability of wastewater containing Reactive Yellow 145 (RY 145) dyestuff by ozonation process has been investigated. The initial concentration of the wastewater containing RY 145 is 50 mg / L. In the study, pH, O3 dose and reaction time parameters have been studied in RY 145 dye removal. The most appropriate removal of RY 145 from wastewater have occured at pH 5, 0.05 g / L.sa O3 dose and 10 minutes reaction time. The removal efficiency of RY 145 has obtained as 99.07% under optimum conditions.

Synthesis of highly porous iron-doped carbonated hydroxyapatite spheres for efficient adsorption of carmine dyes

Highly porous Fe-doped carbonate hydroxyapatite spheres (Fe-CHAs) were synthesized by two-step hydrothermal method and characterized by SEM, XRD and FTIR. The synthesized Fe-CHAs were confirmed as B-type substituted CHAs. Fe-CHAs with desirable hierarchical mesoporous structure exhibited BET surface area of 93.8 m2/g, pore diameter of 37.4 nm, and pore volume of 0.523 cm3/g. Carmine dye was chosen as model organic dye to investigate the adsorption properties of Fe-CHAs. The maximum adsorption capacity of Fe-CHAs was 55.89 mg/g, which was about seven times as much as that of HA powder. Adsorption kinetics carmine dye molecules onto Fe-CHAs followed the second-order kinetic equation and Langmuir model, indicating that adsorption of carmine dye molecules onto Fe-CHAs was mainly monolayer chemical adsorption. Experimental results show that these highly porous Fe-CHAs could be a potential efficient adsorption material for removing organic dyes in industrial wastewater.

Biofilm mediated decolorization and degradation of reactive red 170 dye by the bacterial consortium isolated from the dyeing industry wastewater sediments

Reactive dyes are extensively used in a plethora of industries, which in turn release toxic wastes into the environment. The textile dye waste remediation is crucial as it may contain several toxic elements. The utilization of bacterial consortium for bioremediation has acquired consideration, over the utilization of single strains. In this study, a microbial consortium containing three bacterial sp. (Bacillus subtilis, Brevibacillus borstelensis and Bacillus firmus) was tested for its degrading ability of the textile RR 170 dye. The bacterial consortium degraded the dye effectively at lower concentrations and the efficiency decreased as the dye concentration increased. SEM analysis revealed that, with dye treatment, the consortium appeared as tightly packed clumps with rough cell surface and were able to produce EPS and biofilms. EPS production was higher at 40 mg/l, 100 mg/l and 200 mg/l of the dye treatment conditions. Interestingly, the maximum biofilm formation was observed only at 40 μg/ml of the dye treatment, which indicates that RR 170 dye concentration affects the biofilm formation independent of EPS levels. The UV–vis spectroscopy, HPLC, FTIR and 2D-FTIR analyses confirmed the decolorization and biodegradation of RR 170 dye by the bacterial consortium. Toxicological studies performed with the dye and their degraded products in Allium cepa root cells revealed that, whereas the RR 170 dye induced genotoxic stress, the degraded dye products showed no significant genotoxic effects in root cells. Together, the investigated bacterial consortium decolorized and degraded the RR 170 dye resulting in metabolites that are non-toxic to the living cells.

Synthesis of new Zn (II) complexes for photo decomposition of organic dye pollutants, industrial wastewater and photo-oxidation of methyl arenes under visible-light

Synthesis of new Schiff’s base Zn-complexes for photo-oxidation of methyl arenes and xylenes are reported under visible light irradiation conditions. All the synthesized new ligands and Zn-complexes are thoroughly characterized with various spectral analyses and confirmed as 1:1 ratio of Zn and ligand with distorted octahedral structure. The bandgap energies of the ligands are higher than its Zn-complexes. These synthesized new Zn(II) complexes are used for the photo-fragmentation of organic dye pollutants, photodegradation of food industrial wastewater and oxidation of methyl arenes which are converted into its respective aldehydes with moderate yields under visible light irradiation. The photooxidation reaction dependency on the intensity of the visible light was also studied. With the increase in the dosage of photocatalyst, the methyl groups are oxidized to get aldehydes and mono acid products, which are also identified from LC-MS data. Finally, [Zn(PPMHT)Cl] is with better efficiency than [Zn(PTHMT)Cl] and [Zn(MIMHPT)Cl] for oxidation of methyl arenes is reported under visible-light-driven conditions.

Textile Industry Wastewater Treatment by Cavitation Combined with Fenton and Ceramic Nanofiltration Membrane

This work first time reports the intensification of real wastewater treatment by combination of hydrodynamic cavitation (HC), Fenton reagent, and membrane separation. In this work, a micro-porous ceramic membrane was used for the preparation of nano-porous catalytic membrane reactor. Initially, the aluminium boehmite sol has been synthesized and coated onto the tube side of the ceramic membrane by wet impregnation technique. A layer by layer technique was adopted for the wet impregnation of boehmite sol onto the ceramic membrane. After achieving a desired number of layers coating onto the ceramic membrane, a prepared catalyst sol was further used for coating. The dried boehmite powder was characterized using X-ray diffractometer and particle size distribution analysis. Mercury intrusion porosimetry (MIP) technique was used to identify the pore size distribution of modified ceramic membrane. The modified ceramic membrane was used in conjunction with HC for industrial dye wastewater treatment. The impact of process parameter such as cavitation unit (orifice) inlet pressure, intensifying chemical additive like Fenton reagent, and H2O2 dosage was investigated. HC along with intensifying chemical additives H2O2 and Fenton reagent improved the organic pollutants removal from textile industry wastewater

Potential of Strychnos Potatorum and Eirchorrnia Crassipes in Treating Dyeing Industry Waste

The research aim is to the treatment of industrial dyeing waste water for the analysis of improved water treatment using natural coagulants. For waste water treatment, natural coagulants such as Strychnos potatorum (nirmali seeds) and Eirchorrnia crassipes (water hyacinth) are used. We have test the various properties of dyeing waste water before and after treatment like pH, sulphates, chlorides, total solids, total suspended solids (TSS), total dissolved solids (TDS), acidity, alkalinity, optimum coagulant dosage (jar apparatus), biological oxygen demand (BOD) and chemical oxygen demand (COD) .The test results showed that natural coagulants produce better results when used alone or in conjunction with the chemical coagulant alum. Since the natural coagulant generates less floc, the cost of sludge treatment is reduced. Water hyacinth outperforms nirmali seed in terms of natural coagulants. Natural coagulants may be used to manage and treat the dyeing waste water, anywhere there is an abundance of it.

Adsorptive removal of methylene blue and acid orange 10 dyes from aqueous solutions using oil palm wastes-derived activated carbons

Presence of toxic dyes in industrial wastewaters deteriorates the environment. Wastewater pollution control using locally obtainable agricultural by-products could be an eco-friendly and sustainable strategy. Efficiencies of activated carbons (AC) developed from empty fruit bunches (EFB) and mesocarp fibers (MF) of oil palm were evaluated in methylene blue (MB) and Acid orange 10 (AO10) dyes removal. Impacts of operational parameters including adsorbent dose, pH, initial concentration of dyes, and contact time were examined on dyes adsorption. Maximum adsorption values of MB (24.00 mg/g) and AO10 (18.76 mg/g) were achieved at pH 2 and 3, respectively, 50 mg/L initial dyes concentration, adsorbents dosage of 5 g/L, and 90 min contact time. Evaluation of adsorption isotherms revealed that the Freundlich model provided the best fit to the empirical data (R2 ≥ 0.692). MB isotherm through MF, however, was better represented by Langmuir model (R2 = 0.979). MF activated carbon showed higher capacity in immobilization of both dyes probably due to its larger surface area (552.72 m2/g) and porosity (0.4458 cm3/g). Dye adsorption on to the activated carbons go along with pseudo-second order kinetic model.

Synthesis of Highly Porous Iron-Doped Carbonated Hydroxyapatite Spheres for Efficient Adsorption of Carmine Dyes

Highly porous Fe-doped carbonate hydroxyapatite spheres (Fe-CHAs) were synthesized by two-step hydrothermal method and characterized by SEM, XRD and FTIR. Fe-CHAs with desirable hierarchical mesoporous structure exhibited BET surface area of 93.849 m2/g, pore diameter of 37.387 nm, and pore volume of 0.523 cm3/g. Carmine dye was chosen as model organic dye to investigate the adsorption properties of Fe-CHAs. The adsorption capacity of Fe-CHAs is about seven times as much as that of HA powder. Adsorption kinetics carmine dye molecules onto Fe-CHAs followed the second-order kinetic equation and Langmuir model, indicating that adsorption of carmine dye molecules onto Fe-CHAs is mainly monolayer chemical adsorption. Experimental results show that these highly porous Fe-CHAs could be a potential efficient adsorption material for removing organic dyes in industrial wastewater.