Degradation Of Textile Wastewater Research Articles

Kinetic investigation and optimization of a sequencing batch reactor for the treatment of textile wastewater

Discharging of untreated or partially treated textile wastewater is common in Ethiopia, and this has detrimental effect to the environment. It is difficult to treat textile wastewater by conventional biological processes. In this study, real textile wastewater was taken and treated using sequencing batch reactor using a biomass taken from domestic wastewater treatment plant. Cycle period, air flowrate and sludge retention time (SRT) were initially optimized using the response surface methodology. The optimum ratio of cycle period/air flowrate/SRT which gives a 57% COD removal and 54% color removal was found to be 25 h/15 L/h/16 day. Using two types of wastewater substrate concentrations and various hydraulic retention times at optimized condition, COD removal, color removal, sludge volume index (SVI) and mixed liquor suspended solid were measured. The maximum of COD removal (73%) and color removal (65.8%) was obtained at an organic loading rate of 0.078 kg COD/m3 day. SVI at the optimized condition was found to be 90–92 mL/g. Finally, a first-order kinetic model was used to represent the degradation of textile wastewater.

TiO2/anthill clay as a heterogeneous catalyst for solar photocatalytic degradation of textile wastewater: Catalyst characterization and optimization studies

This present study aims at revealing the activity of TiO2–anthill clay in photocatalytic degradation of textile effluent. It also aims to investigate the effects of parameters affecting the photocatalytic degradation process such as catalyst dose (0.5–25 wt.%), reaction time (1–3 h) and solution pH (2–10) through central composite design. The synthesized photocatalyst was characterized using BET, SEM, EDX, FTIR, and XRF techniques. The results obtained from the optimization studies revealed that there were good agreements between the predicted and observed values of photocatalytic degradation efficiency. The maximum decolorization efficiency of 70.92% was obtained under the optimum experimental conditions of 2.50 wt.% catalyst dose, 1.07 h reaction time, and dye solution pH of 2.0. The TiO2-anthill photocatalyst was found to be efficient for complete decolorization of dye solution as it was able to be reused for up to four cycles.

Textile Wastewater Treatment by Using Plasma Corona Discharge in a Continuous Flow System

This study aimed to figure out plasma corona discharge for textile wastewater degradation with continuous flow system. Plasma reactor using AC voltage of 11.5 kV and two stainless steel electrode which set up parallelly 4.0±0.5 mm above wastewater. Continuous flow system means the wastewater flowing continuously with flow rate of 60 ml/min. Characteristics of absorbance, pH, temperature, Total Dissolved Solid (TDS), Total Suspended Solid (TSS) and conductivity were measured before and after plasma treatment. Absorbance, pH and TSS value of wastewater were decrease after plasma treatment,. While the TDS, conductivity and the temperature were relatively increase. This result indicate better quality of wastewater.

Effects of different scrap iron as anode in Fe-C micro-electrolysis system for textile wastewater degradation.

The degradation of organic contaminants in actual textile wastewater was carried out by iron carbon (Fe-C) micro-electrolysis. Different Fe-C micro-electrolysis systems (SIPA and SISA) were established by using scrap iron particle (SIP) and scrap iron shaving (SIS) as anode materials. The optimal condition of both systems was obtained at the initial pH of 3.0, dosage of 30g/L and Fe/C mass ratio of 1:1. Commercial spherical Fe-C micro-electrolysis material (SFC) was used for comparison under the same condition. The results indicated that total organic carbon (TOC) and chroma removal efficiencies of SIPA and SISA were superior to that of SFC. Total iron concentration in solution and XRD analysis of electrode materials revealed that the former showed relatively high iron corrosion intensity and the physicochemical properties of scrap iron indeed affected the treatment capability. The UV-vis and 3DEEM analysis suggested that the pollutants degradation was mainly attributed to the combination of reduction and oxidation. Furthermore, the potential degradation pathways of actual textile wastewater were illustrated through the GC-MS analysis. Massive dyes, aliphatic acids, and textile auxiliaries were effectively degraded, and the SIPA and SISA exhibited higher performance on the degradation of benzene ring and dechlorination than that by SFC. In addition, SIPA and SISA exhibited high stability and excellent reusability at low cost. Graphical abstract.

Study of textile wastewater degradation using plasma corona discharge in batch system

Textile wastewater with high concentration of dye caused by coloring and finishing process has been polluting the environment. Plasma is one of wastewater treatment required to degrade the dyes. In this study, plasma corona discharge was used to degrade the batik wastewater. Plasma corona discharge is generated by an AC voltage of 11.5 kV through one or two pair stainless steel electrode with diameter of 2±0.05 mm. The electrodes are placed 3 mm above the batik wastewater. The result show a decrease absorbance at wavelength of 400-500 nm. The treatment time of one pair electrode is 2 hours and 3.5 hours. While for two pairs electrode treated in 1 hour and 1.5 hour to get approximatelly same result with one pair. The percentage degradation of dye for one and two pairs of electrodes are 39.08; 50.85; 39.08; and 42.83%, respectively.

Enhanced photocatalytic degradation of textile wastewater using Ag/ZnO thin films

In this work, photodegradation of a synthetic textile wastewater composed of a mixture of three reactive azo dyes (RO 122, RR 195 and RY 145) was performed using silver doped zinc oxide (Ag/ZnO) thin films. The photocatalyst preparation was conducted through sol-gel method and was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and ultraviolet-visible (UV–vis) spectroscopy. The photocatalytic activity of Ag/ZnO thin film was assessed by measuring the decolorization rate constant of the dyes mixture spectrophotometrically. The chemical structure of each dye influences the photodegradation rate either in mixture or in individual dyes solutions. Several parameters which influence photocatalytic degradation such as catalyst dose, dyes concentrations as well as addition of hydrogen peroxide as an electron acceptor have been studied. The results revealed that these parameters should be optimized to obtain the maximum photocatalytic degradation.

Influence of PVP surfactant on the morphology and properties of ZnO micro/nanoflowers for dye mixtures and textile wastewater degradation

Flower-like ZnO micro/nanostructures were successfully prepared using a polyvinylpyrrolidone (PVP)-assisted co-precipitation route and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopy. Smaller sizes of ZnO micro/nanoflowers were synthesized with different amounts of PVP as surfactant. Possible morphology evolution and formation mechanism of the flower-like micro/nanostructures were postulated. Concentrations of PVP in the reaction mixtures served as key role for morphology-controlled synthesis of ZnO as PVP can assist the oriented crystal growth during the synthesis. The as-synthesized ZnO samples prepared at 12.5 mg/mL PVP displayed higher photoactivity for the simultaneous degradation of methyl orange and methyl green mixtures. The photocatalytic tests also indicated that process parameters such as the initial dye concentration and solution pH exerted their individual influences on the dye mixtures degradation. Under determined experimental conditions, 94.1% chemical oxygen demand (COD) removal of dye mixtures was attained after 240 min of reaction. The ZnO photocatalytic degradation of real textile wastewater was then evaluated and a lower COD removal efficiency (∼75%) was observed at similar treatment duration. Other real textile wastewater quality parameters of biochemical oxygen demand (BOD5), turbidity, total suspended solid (TSS), colour, ammoniacal nitrogen (NH3-N) and pH were also investigated.

Waste treatment of remazol blue compounds based on ozonation/AOP in a bubble column reactor

Increased production in the textile industry has the potential to result in high dye waste water. Various conventional methods to handle with textile waste treatment have been done, but still considered not yet or less effective. The AOP technology (Advanced Oxidation Processes) applied in this research is a rapid degradation technology in textile wastes with advanced oxidation process through the formation of hydroxyl radical (OH) which is considered to optimize the degradation process of textile dye waste. This study aims to evaluate the performance of ozonation methods and AOP (O3/UV/H2O2) in dye degradation of textile wastewater containing remazol blue compounds. Both configuration methods used are optimized in several parameters such as waste flow rate, ozone voltage and pH to obtain maximum remazol blue degradation. From this study, the higher percentage to remazol blue degradation is 99.99%, which is achieved by AOP method, with double air injection air flow rate of 10 L/min and 0.25 L/min liquid flow rate.

Hydrogen peroxide-assisted photocatalytic degradation of textile wastewater using titanium dioxide and zinc oxide

ABSTRACTThe present work investigated the degradation of a dyeing factory effluent by advanced oxidative process under UV irradiation. TiO2 and ZnO were used as catalysts and the influence of different concentrations of H2O2 added to the system was studied. The catalysts were characterized in terms of crystal structure (X-ray diffraction), textural properties (Brunauer–Emmett–Teller area and pore volume) and point of zero charge, which indicated the semiconductors had a positively charged surface in an acidic medium. After 8 h of irradiation at pH 3.0 and catalyst concentration of 0.0625 g L−1, the effect of H2O2 was evaluated by means of kinetic efficiency (rate constants), absorbance reduction (at 284, 621 e 669 nm), total organic carbon reduction and mineralization (in terms of the formation of ions such as and ). Adding H2O2 to the photocatalytic system significantly increased pollutants’ removal, highlighting tests with 1.0 × 10−2 mol L−1, showing higher absorbance reduction and rate constants at 621 and 669 nm for TiO2 and best mineralization rates for ZnO. Ecotoxicity bioassays using Artemia salina L confirmed the treatment efficacy, with effluent lethal concentration (LC50) increasing from 65.68% (in natura) to over 100% after photocatalysis treatment.

Degradation of textile wastewater by modified photo-Fenton process: Application of Co(II) adsorbed surfactant-modified alumina as heterogeneous catalyst

Fenton method is well recognized for organic pollutant degradation. However, traditional Fenton method has several drawbacks for practical application. In this regard different catalysts and modified Fenton processes are developed for better efficiency. In this study, a new catalyst is developed for methylene blue (MB) and methyl orange (MO) degradation under heterogeneous photo-Fenton process in presence of H2O2 and visible light. Finally, the catalyst was successfully applied for real textile wastewater degradation also. Here the as-prepared catalyst is the Co(II), which is adsorbed on the bilayer structure of sodium dodecyl sulfate (an anionic surfactant) formed on alumina support. The catalyst is designated as Co-SMA. The degradation characteristics of both the dyes are discussed. The MB, being a cationic dye, gets fully adsorbed on Co-SMA surface and the reaction proceeds on the solid surface with zero order kinetics. On the other hand, the degradation of MO follows first order kinetics because of its low adsorption. The efficiency of decolorization of real wastewater is found to be >92% in 60min time of reaction with 10gL−1 of Co-SMA, 37.9mM H2O2 and 10,010lx light intensity. Leaching of cobalt from Co-SMA is very less during the reaction which is advantageous for environmental applications.

Comparison of coagulation, ozone and ferrate treatment processes for color, COD and toxicity removal from complex textile wastewater.

In this study, the comparative performance of coagulation, ozone, coagulation + ozone + coagulation and potassium ferrate processes to remove chemical oxygen demand (COD), color, and toxicity from a highly polluted textile wastewater were evaluated. Experimental results showed that ferrate alone had no effect on COD, color and toxicity removal. Whereas, in combination with FeSO4, it has shown the highest removal efficiency of 96.5%, 83% and 75% for respective parameters at the optimal dose of 40 mgL-1 + 3 ml FeSO4 (1 M) in comparison with other processes. A seed germination test using seeds of Spinach (Spinacia oleracea) also indicated that ferrate was more effective in removing toxicity from contaminated textile wastewater. Potassium ferrate also produces less sludge with maximum contaminant removal, thereby making the process more economically feasible. Fourier transform infrared spectroscopy (FTIR) analysis also shows the cleavage of the chromophore group and degradation of textile wastewater during chemical and oxidation treatment processes.

Visible light photocatalytic degradation of textile waste water by Co doped NiFe2O4 nanocomposite

Synthesis of magnetic nanoparticles has been intensively pursued due to their unique functional properties. In this paper a Co doped NiFe2O4 was synthesized. The magnetic measurements of Co doped NiFe2O4 showed that the photocatalyst material can be separated from water when an external magnetic field is applied and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for waste water treatment. The photocatalytic activity of Co doped NiFe2O4 was investigated by using the photo-decomposition of methylene blue and some textile dyes under visible light. The structure of this nanocomposite is studied by UV–Vis spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, field emission scanning electron microscopy and scanning energy dispersive X-ray spectroscopy.

Photocatalytic activity of TiO2, ZnO and Nb2O5 applied to degradation of textile wastewater

Abstract In this work, photocatalysis was employed in the treatment of textile effluent from industrial laundry jeans using the catalysts TiO2 P25 (commercial), TiO2, ZnO and Nb2O5, under artificial UV irradiation. The parameters investigated were: pH of the solution and catalyst concentration. The photocatalytic activity was evaluated by means of kinetic efficiency (rate constant and half life time), thermodynamic (absorbance reduction at 228, 254, 284, 310, 350, 500 and 660 nm), COD reduction, mineralization in terms of the formation of inorganic ions (NH4+, NO3−, NO2−, SO42− and Cl−) and toxicity reduction (bioassays using Artemia salina). The photocatalytic degradation of textile effluent at pH 3.0 and catalyst concentration of 0.250 g L−1 showed the best results, being found 95.91%; 87.35%; 86.95% and 59.18% of absorbance reduction at 660 nm (λmax) after 300 min of artificial irradiation with TiO2 P25, Nb2O5, TiO2 and ZnO, respectively. TiO2 and Nb2O5 were responsible for the reduction of approximately 70 and 66% of COD and the photocatalytic activity of TiO2 was very close to TiO2 P25. In this sense, Nb2O5 becomes a promising alternative to replace the commercial TiO2 P25. Bioassays with Artemia salina confirmed the efficacy of the treatment, indicating that after photodegradation there was an expressive decrease in effluent toxicity for up to 3 times.

Eco-friendly and facile integrated biological-cum-photo assisted electrooxidation process for degradation of textile wastewater

The present article reports an integrated treatment method viz biodegradation followed by photo-assisted electrooxidation, as a new approach, for the abatement of textile wastewater. In the first stage of the integrated treatment scheme, the chemical oxygen demand (COD) of the real textile effluent was reduced by a biodegradation process using hydrogels of cellulose-degrading Bacillus cereus. The bio-treated effluent was then subjected to the second stage of the integrated scheme viz indirect electrooxidation (InDEO) as well as photo-assisted indirect electro oxidation (P-InDEO) process using Ti/IrO2–RuO2–TiO2 and Ti as electrodes and applying a current density of 20 mA cm−2. The influence of cellulose in InDEO has been reported here, for the first time. UV–Visible light of 280–800 nm has been irradiated toward the anode/electrolyte interface in P-InDEO. The effectiveness of this combined treatment process in textile effluent degradation has been probed by chemical oxygen demand (COD) measurements and 1H – nuclear magnetic resonance spectroscopy (NMR). The obtained results indicate that the biological treatment allows obtaining a 93% of cellulose degradation and 47% of COD removal, increasing the efficiency of the subsequent InDEO by a 33%. In silico molecular docking analysis ascertained that cellulose fibers affect the InDEO process by interacting with the dyes that are responsible of the COD. On the other hand, P-InDEO resulted in both 95% of decolorization and 68% of COD removal, as a result of radical mediators. Free radicals generated during P-InDEO were characterized as oxychloride (OCl) by electron paramagnetic resonance spectroscopy (EPR). This form of coupled approach is especially suggested for the treatment of textile wastewater containing cellulose.

Mutagenicity, cytotoxicity and phytotoxicity evaluation of biodegraded textile effluent by fungal ligninolytic enzymes.

Colored effluents from the textile industry have led to severe environmental pollution, and this has emerged as a global issue. The feasibility of ligninolytic enzymes for the detoxification and degradation of textile wastewater was investigated. Ganoderma lucidum crude ligninolytic enzymes extract (MnP 717.7, LiP 576.3, and Laccase 323.2 IU/mL) was produced using solid-state culture using wheat bran as substrate. The biodegradation treatment efficiency was evaluated on the basis of degradation and detoxification of textile effluents. Standard bioassays were employed for mutagenicity, cytotoxicity and phytotoxicity evaluation before and after biodegradation. The degradation of Masood Textile, Kalash Textile, Khyber Textile and Sitara Textile effluents was achieved up to 87.29%, 80.17%, 77.31% and 69.04%, respectively. The biochemical oxygen demand, chemical oxygen demand, total suspended solids and total organic carbon were improved considerably as a result of biodegradation of textile effluents, which were beyond the permissible limits established by the National Environmental Quality Standards before treatment. The cytotoxicity (Allium cepa, hemolytic, Daphnia magna and brine shrimp), mutagenicity (Ames TA98 and TA100) and phytotoxicity (Triticum aestivum) tests revealed that biodegradation significantly (P < 0.05) detoxifies the toxic agents in wastewater. Results revealed that biodegradation could possibly be used for remediation of textile effluents. However, detoxification monitoring is crucial and should always be used to evaluate the bio-efficiency of a treatment technique.

Recent advances and prospects of catalytic advanced oxidation process in treating textile effluents

AbstractIn the past few years, there have been many researches on the use of different types of homogenous catalyst for the degradation of textile wastewater in conventional advanced oxidation processes (AOPs). However, homogenous AOPs suffer from few limitations, including large consumption of chemicals, acidic pH, high cost of hydrogen peroxide, generation of iron sludge, and necessity of post-treatment. Therefore, recently, there have been more researches that focus on improving the performance of conventional AOPs using heterogeneous catalysts such as titanium dioxide, nanomaterials, metal oxides, zeolite, hematite, goethite, magnetite, and activated carbon (AC). Besides, different supports such as AC that have been incorporated with transition metals and clays have been proven to have excellent catalytic activity in AOPs. This paper presents a comprehensive review of advances and prospects of catalytic AOPs for the decontamination of a wide range of synthetic and real textile wastewater. This review provides an up-to-date critical review of the information on the degradation of various textile dyes by a wide range of heterogeneous catalysts and adsorbents. The future challenges of AOPs, including chemical consumption, toxicity assessment, reactor design, and limitation of catalysts, are discussed in this paper. In addition, this paper also discusses the presence of ions, generation of by-products, and industrial applications of AOPs. Special emphasis is given to recent studies and large-scale combination of AOPs for wastewater treatment. This review paper concludes that more studies are needed for the kinetics, reactor design, and modeling of hybrid AOPs and the production of their corresponding intermediate products and secondary pollutants. A better economic model should also be developed to predict the cost of AOPs, as the treatment cost varies with dyes and textile effluents.

Photocatalytic degradation of textile wastewater in presence of hydrogen peroxide: Effect of cerium doping titania

Ce–TiO2 catalysts synthesized through sol–gel method were explored for textile wastewater photocatalytic degradation in presence of H2O2. Synthesized materials were characterized by X-ray diffraction, Raman spectroscopy, UV–visible diffuse reflectance spectroscopy, N2 physisorption at 77K and H2-temperature programmed reduction. Suitable amount of cerium (1%) significantly inhibits the electron–hole pairs recombination and reduces the energy gap values of the materials. 1% Ce–TiO2 catalyst demonstrated superior catalytic performances permitting a 40% and 55% of TOC and color conversions, respectively. The relationship between photocatalytic activity and physicochemical properties was discussed. Environmental impact of textile wastewater was evaluated by the bioluminescence test using the LUMIStox.

Integrated process of fungal membrane bioreactor and photocatalytic membrane reactor for the treatment of industrial textile wastewater

In this study, fungal membrane bioreactor (FMBR) and semiconductor photocatalytic membrane reactor (PMR) were used in order to test the efficiency of integrated fungal biodegradation and photocatalytic degradation of textile wastewater from reactive washing processes. It was found that color removal and chemical oxygen demand (COD) reduction efficiencies were 88% and 53% for photocatalytic degradation, respectively. TiO2 and ZnO were tested as semiconductor catalysts in the PMR and TiO2 showed better efficiencies than ZnO for both color and COD removal. However, it was attained that color removal and COD reduction efficiencies were about 56% and 60% for fungal biodegradation using Phanerochaete chrysosporium, respectively. Moreover, integrated system in which photocatalytic degradation was employed as a post-treatment application after fungal biodegradation process achieved high removal efficiencies for color and COD removal as 93% and 99%, respectively.

Efficient solar photocatalytic degradation of textile wastewater using ZnO/ZTO composites

Zinc oxide/zinc tin oxide (ZnO/ZTO) nanocomposites were synthesized on porous ceramic support using a simple and economical hydrothermal technique for photocatalytic degradation of organic dyes. One dimensional ZnO nanorods were grown epitaxially on ZnO nanoparticles seeded substrates in a chemical bath with different growth solution concentrations followed by the synthesis of zinc tin oxide (ZTO) in an autoclave. Comparison of photocatalytic activity of pure ZnO nanorod catalysts with different dimensions on the degradation of methylene blue showed that ZnO nanorods (ZnO20mM) with the highest specific surface area (45m2g−1) are 13% more active than those with lower surface areas ZnO nanorod catalysts (ZnO1mM, ZnO5mM and ZnO10mM; 20–39m2g−1). To further enhance photocatalytic activity, we composited ZnO with ZTO and found that ZnO/15ZTO can be a better photocatalyst improving 16% degradation efficiency attributed to the reduction of electron–hole recombination by charge carrier separation in the composites. Moreover, ZnO/15ZTO showed 50% Photocatalytic degradation efficiency and 77% COD removal of textile waste water when irradiated by sunlight. ZnO/ZTO monolith shows much promise to be an attractive photocatalyst for solar photocatalytic application.

Effect of solution pH on the performance of three electrolytic advanced oxidation processes for the treatment of textile wastewater and sludge characteristics

Comparative removal of COD and color from real textile wastewater using three different electrolytic advanced oxidation processes, namely, electro-Fenton (EF), peroxicoagulation (PC) and pH-regulated peroxicoagulation (PC-pH) processes were analyzed in the present study. Graphite plates were used as both electrodes in the EF process, while an iron plate replaced the graphite anode in the PC and PC-pH processes; moreover, the effect of voltage and solution pH on the performance of these processes was compared. Sludge production was observed in peroxicoagulation processes, indicating that the removal of pollutants took place by both degradation and electrocoagulation processes. The sludge production increased with an increase in solution pH, indicating that the electrocoagulation process dominates the degradation process at higher pH. A reduction of 97% in color was observed in the EF and PC-pH processes, while in the PC process was 82% after 60 min of electrolysis. At the same time, 64%, 70% and 75% of COD was removed by the EF, PC-pH and PC processes, respectively. Moreover, 47.7% of organic pollutant was mineralized via the EF process, and the sludge produced was characterized using the SEM, XRD and FTIR techniques. Furthermore, the sludge produced from the peroxicoagulation process was used as a heterogeneous EF catalyst for the degradation of textile wastewater, and removal of 97% of color, 47% of COD and 33.2% of TOC was observed.