Textile Dyeing Wastewater Research Articles

Biodegradation of textile dyeing industry wastewater using modified anaerobic sequential batch reactor – Start-up, parameter optimization and performance analysis

Abstract In this study a novel modified anaerobic sequential batch reactor (MASBR) was employed to treat the textile dyeing industry wastewater. The anaerobic sequential batch reactor (ASBR) was modified by the addition of a sorbent (ground nut shell powder) and plastic media. The start-up phase of the MASBR was observed over a period of 80 days. Statistical based experiments were performed in order to optimize the parameters viz., sorbent dosage and particle loading, and to study the interactive effects using response surface method (RSM). At the optimized conditions, experiments were performed at various organic loading rates by varying initial textile dye wastewater concentration and hydraulic retention time (HRT). The anaerobic biodegradation of textile dyeing wastewater in the MASBR was analyzed in terms of decolorization, COD reduction, biogas production, volatile fatty acids (VFA) at different organic loading rate (OLR) between 0.110 and 0.650 kgCOD/m3 d. A maximum decolorization of 94.8% and COD reduction of 97.1% were obtained in the MASBR. The novel sorbent utilized in the study was characterized using FTIR and SEM analysis.

Validity of Egyptian Na‐montmorillonite for adsorption of Pb2+, Cd2+ and Ni2+ under acidic conditions: characterization, isotherm, kinetics, thermodynamics and application study

AbstractThis study investigated the applicability of natural Egyptian Na‐montmorillonite (Na‐MMT) to remove Pb2+, Cd2+ and Ni2+ under acidic conditions that mimic industrial wastewater acidity. Cation exchange capacity of Na‐MMT was found 91 meq/100 g and the specific surface area 42 m2 g−1. The adsorbent was characterized using X‐ray fluorescence, scanning electron micrograph that showed significant morphological changes after adsorption and Fourier transform infrared spectroscopy, which confirmed that the adsorption occurred mainly in the lattice region. Removal efficiency was evaluated as a function of pH, contact time, initial concentration, and adsorbent mass. Acidic pH value was chosen for the following experiments. Langmuir and Freundlich isotherm models were applied. Freundlich model showed better fitting suggesting heterogeneous adsorption scenario. Freundlich capacity values decreased in the order of Pb2+ (3.71 mg g−1) > Cd2+ (2.45 mg g−1) > Ni2+ (1.76 mg g−1). Kinetic data were accurately fitted to pseudo‐second‐order, indicating the adsorption occurrence in the interior surface of Na‐MMT and the contribution of internal diffusion mechanism was significant. Intraparticle diffusion model gave multi‐linear curves so more than one‐step controlled the adsorption process. Under temperature range 290–328 K, thermodynamic parameters revealed that adsorption of Pb2+ and Cd2+ was spontaneous but Ni2+ non‐spontaneous. Adsorption was exothermic for Pb2+ and Ni2+ but endothermic for Cd2+. Arrhenius activation energy values were 5.78, 8.51 and 11.45 kJ mol−1 for Pb2+, Cd2+ and Ni2+ respectively stating the physical adsorption. Na‐MMT reusability was confirmed by regeneration experiments. Application study showed excellent efficiency of Na‐MMT within range (23.4–81.2%) removal for Pb2+, Cd2+ and Ni2+ from textile dyeing and tannery wastewater. Copyright © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

Evaluation of starch-based flocculants for the flocculation of dissolved organic matter from textile dyeing secondary wastewater

China is a major textile manufacturer in the world; as a result, large quantities of dyeing effluents are generated every year in the country. In this study, the performances of two cationic starch-based flocculants with different chain architectures, i.e., starch-graft-poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride] (STC-g-PDMC) and starch-3-chloro-2-hydroxypropyl trimethyl ammonium chloride (STC-CTA), in flocculating dissolved organic matter (DOM) in dyeing secondary effluents were investigated and compared with that of polyaluminum chloride (PAC). In the exploration of the flocculation mechanisms, humic acid (HA) and bovine serum albumin (BSA) were selected as main representatives of DOM in textile dyeing secondary effluents, which were humic/fulvic acid-like and protein-like extracellular matters according to the studied wastewater’s characteristics based on its three-dimensional excitation–emission matrix spectrum. According to experimental results of the flocculation of both the real and synthetic wastewaters, STC-g-PDMC with cationic branches had remarkable advantages over STC-CTA and PAC because of the more efficient charge neutralization and bridging flocculation effects of STC-g-PDMC. Another interesting finding in this study was the reaggregation phenomenon after restabilization at an overdose during the flocculation of BSA effluents by STC-g-PDMC at a very narrow pH range under a nearly neutral condition. This phenomenon might be ascribed to the formation of STC-g-PDMC/BSA complexes induced by some local charge interactions between starch-based flocculant and the amino acid fragments of protein due to charge patch effects.

Advanced treatment of actual textile dye wastewater by Fenton‐flocculation process

AbstractTo improve the performance of actual textile dye wastewater treatment, an advanced treatment combining the Fenton and flocculation processes was developed. The parameters affecting decolorization in the Fenton‐flocculation process, including initial pH, H2O2 dosage, Fe2+dosage, reaction temperature, reaction time, and flocculant dosage, were examined. With the optimal Fenton‐flocculation condition parameters, more than 95 % COD removal, 99 % colour removal, and 99 % turbidity removal were obtained. UV‐visible spectra of raw water and supernatant were further obtained after the Fenton‐flocculation process, and results demonstrated that the chromophoric groups and the conjugated system in the dye molecular structure were destroyed. All these results confirmed that the Fenton‐flocculation process was a favourable and effective post‐treatment method for actual textile dye wastewater.

Reuse of waste activated sludge for textile dyeing wastewater treatment by biosorption: performance optimization and comparison

AbstractThe aim of this study is to assess the ability of local low‐cost biomaterials to remove reactive dyes from aqueous solutions. Granules prepared from dried activated sludge (DAS) were used as a sorbent for the removal of red bimacid dye (E5R) chosen as model dye. The study involves batch type experiments to investigate the effects of initial dye concentration, adsorbent dose, contact time, temperature and pH of solution on biosorption process. Optimal experimental conditions were ascertained. The pseudo‐second‐order kinetic model fits very well with the experimental results. The thermodynamic parameters for the biosorption process have also been calculated and found the sorption process as exothermic. The sorption performance of this DAS is finally compared with that of different reference sorbents and of other low‐cost materials.

UV/Fenton photo-oxidation of Drimarene Dark Red (DDR) containing textile-dye wastewater

Textile dye wastewater contains organic pollutants which are non-biodegradable, characterized by low BOD/COD ratio of typically < 0.01. Therefore to treat such wastewater, the destructive wastewater treatment methods which can be utilized are the Advanced Oxidation Processes (AOPs). One of the AOPs method which is the UV/H2O2/Fe2+ (or UV/Fenton) offers not only relatively low cost but also quite effective (in terms of color removal and reaction time) treatment. This particular research aimed to optimize the conditions of UV/Fenton photo-oxidation process for Drimarene Dark Red containing textile- dye wastewater. The two main operating conditions to be optimized were the initial concentration of H2O2 ranged between 0.022-0.078 %-w and the mol ratio of Fe2+: H2O2 was varied from 1: 13 up to 1: 45, using the Central Composite Design experimental matrix. The photo-oxidation was carried out at the optimum pH of 3 from some previous experiments. The best processing conditions of the photo-oxidation of Drimarene Dark Red (DDR) were found at the initial concentration of H2O2 at 0.050%-w and the mole ratio Fe2+: H2O2 of 1: 22. Under these conditions, the measured 2nd order pseudo-rate constantwas 0.021 M-1.min-1. The DDR color removal of 90% was surprisingly achievable within only 10 minutes reaction time.

Degradation of residual dyes in textile wastewater by ozone: Comparison between mixed and bubble column reactors

A noticeable amount of dyes may remain in the wastewater downstream of dyeing facilities giving anaesthetic colourations as well as environmental concerns. Conventional biological treatment alone cannot guarantee a sufficient decolouration and tertiary treatments have to be necessarily considered. Two oxidation schemes by ozone were considered in this work. A bubble column reactor (as a benchmark, in agreement with industrial applications) and a recycle well‐mixed reactor were compared to reach the highest decolouration of standard dyes. In addition, hydrodynamic and ultrasonic cavitation were considered in the recycled well‐mixed reactor to intensify its performance. The decolouration analysis was carried out for two dye classes (reactive and disperse), characterized by very different physical and chemical features. It appeared that some benefit was brought by ultrasound cavitation in the case of disperse dye only, while the degradation of the reactive dye was not intensified by the above hydraulic phenomenon. Ozone treatment was protracted to obtain different decolouration degrees of wastewater generated by wool dyeing. The resulting water was tested as a recycled process fluid to prepare fresh dyeing liquors, where devising the minimum decolouration degree became one of the quality specifications for recycling water back to dyeing.

Effect of potassium on structural, photocatalytic and antibacterial activities of ZnO nanoparticles

ZnO and potassium doped ZnO nanoparticles were synthesized through wet chemical method. The samples were characterized by UV, XRD, SEM, TEM and EDAX. XRD analysis reveals that the prepared nanoparticles exhibit hexagonal wurtzite structure. TEM and SEM analyses disclose that synthesized samples were porous structure with needle shape. It also confirms that potassium was dispersed on ZnO surface. The influence of potassium on ZnO surface modulates the degradation of textile dyeing wastewater by improving its rate of decomposition to 0.007 min−1 with decoloration. A better zone of inhibition of about 20 mm against Staphylococci aureus and Pseudomonas aernginosa by ZnO and potassium doped ZnO nanoparticles were measured. The findings suggest that these nanoparticles have the potential to be a good photocatalyst and applied in water treatment to inhibit the bacterial growth.

Electrochemical Decolorization of Reactive Violet 5 Textile Dye using Pt/Ir Electrodes

Electrochemical decolorization of textile dyeing wastewater containing Reactive Violet 5 (RV5) were investigated at Pt/Ir electrodes in the presence of 75%NaCl+25%Na 2 CO 3 (w/w) supporting electrolyte mixture in a batch electrochemical reactor. Experimental parameters were operated in the range of 300-1500 mg/L textile dye concentration, 4-20 g/L 75%NaCl+25%Na 2 CO 3 electrolyte concentration, 5-15 mA/cm 2 current density, and 20-60°C reaction temperature in 15 min electrolysis time. Reactive Violet 5 decolorization increased with increasing current density and electrolyte concentration, and decreasing the textile dye concentration. Although a slight increase obtained in color removal efficiency, the temperature was not show much significant effect on decolorization. Depending on electrochemical reaction conditions, Reactive Violet 5 textile dye decolorization were obtained between 42.8-100%.

Evaluation of Energy Consumption in Electrochemical Oxidation of Acid Violet 7 Textile Dye using Pt/Ir Electrodes

The effects of process parameters were investigated on the electrochemical oxidation of textile dyeing wastewater containing Acid Violet 7 (AV7) at Pt/Ir electrodes in the presence of 75%NaCl+25%Na 2 CO 3 (w/w) supporting electrolyte mixture in a batch electrochemical reactor. Experimental parameters were operated in the range of 300-1500 mg/L textile dye concentration, 4-20 g/L electrolyte concentration, 5-15 mA/cm 2 current density, and 20-60 °C reaction temperature. Energy consumption decreased with increasing textile dye concentration and electrolyte concentration, and decreasing the current density. In the study, energy consumption values were evaluated for textile dye decolorization (t=15 min) and COD removal (t=120 min) as 2.7-23.3 kWh/kg dye decolorization and 50.9-317.9 kWh/kg COD removal, respectively.

High Laccase Expression by Trametes versicolor in a Simulated Textile Effluent with Different Carbon Sources and PHs.

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 U∙L−1) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs.

Identificación de un consorcio microbiano en humedales construidos de flujo sub-superficial alimentados con aguas residuales industriales coloreadas

In this research, a microbial consortium was isolated from pilot-scale horizontal subsurface flow-constructed wetlands treating rich dye textile wastewater. Wetlands were planted with Phragmites australis, and some parameters,including COD, BOD5, total solids, total suspended solids, total dissolved solids, nitrates, total phosphorus, and metals (Fe, Mn, Zn, Cu, Pb), were monitored in water. Microbial consortia were isolated using an enrichment technique, featuring a mix of four dyes. A total of 24 consortia were isolated with removal percentages above 50%. The consortium with the best dye removal percentage was selected for identification by molecular techniques. This microbial consortium was composed of three different fungus strains and one bacterial strain (Rhodotorula mucilaginosa, Galactomyces seudocandidum, Rhodotorula sp., and Escherichia coli, respectively). On average, removals of COD above 50% and BOD5 above 80% were obtained. Of the five metals evaluated, only Mn and Pb traces were found.

Optimization of photocatalytic degradation of real textile dye house wastewater by response surface methodology.

This study evaluates the advanced oxidation process for decolorization of real textile dyeing wastewater containing azo and disperse dye by TiO2 and UV radiation. Among effective parameters on the photocatalytic process, effects of three operational parameters (TiO2 concentration, initial pH and aeration flow rate) were examined with response surface methodology. The F-value (136.75) and p-value <0.0001 imply that the model is significant. The 'Pred R-Squared' of 0.95 is in reasonable agreement with the 'Adj R-Squared' of 0.98, which confirms the adaptability of this model. From the quadratic models developed for degradation and subsequent analysis of variance (ANOVA) test using Design Expert software, the concentration of catalyst was found to be the most influential factor, while all the other factors were also significant. To achieve maximum dye removal, optimum conditions were found at TiO2 concentration of 3 g L-1, initial pH of 7 and aeration flow rate of 1.50 L min-1. Under the conditions stated, the percentages of dye and chemical oxygen demand removal were 98.50% and 91.50%, respectively. Furthermore, the mineralization test showed that total organic compounds removal was 91.50% during optimum conditions.

Simultaneous spectrophotometric determination and column solid-phase extraction of two Lanaset textile dyes in environmental water samples

A solid-phase extraction method, based on the adsorption onto Diaion HP-20 resin, was developed for simultaneous spectrophotometric determination of Lanaset Blue 2R and Lanaset Yellow 28 dyes which are most together hazardous textile dyes in wastewater. Concentrations of the dyes were determined using UV–visible spectrophotometer at 625 and 438nm for LB-2R and LY-28, respectively. The developed method was also applied to water samples. In dying process water, 572±15μg/mL and 396±6μg/mL of LB-2R and LY-28 dyes were determined. In addition, adsorption isotherms of the method, point of zero charge and surface micrographs of the resin were investigated.

Decolorization of reactive violet 5 dye in textile wastewater by electrocoagulation

&lt;span lang="EN-US"&gt;The textile dyeing industry consumes large quantities of water and produces large volumes of wastewater from different steps in the dyeing and finishing processes. Wastewater from printing and dyeing units is often rich in color, containing residues of reactive dyes and chemicals, such as complex components. This study investigates the decolorization of synthetic dye wastewater containing textile dye Reactive Violet 5 (RV5) by electrocoagulation. A laboratory batch reactor was used to investigate the effect of various operating parameters using aluminium (Al), iron (Fe) and stainless steel (SS) anode. The effect of dye concentration, current density, supporting electrolyte, sup­porting electrolyte concentration, electrolysis duration, and material of anode of the systems were evaluated. Color removal efficiency was 22, 91.5 and 99.8 % in 15 minutes using Al, Fe and SS anode, respectively (j = 10 mA/cm&lt;sup&gt;2&lt;/sup&gt;, c&lt;sub&gt;NaCl &lt;/sub&gt;= 0.171 M).&lt;/span&gt;

Treatment and toxicity reduction of textile dyeing wastewater using the electrocoagulation-electroflotation process

ABSTRACTA pilot-scale study was conducted using the electrocoagulation-electroflotation (EC-EF) process to treat textile dyeing raw wastewater to evaluate treatment performance. The effects of some key factors, such as current density, hydraulic retention time (HRT), and removal of conductivity, total suspended solids (TSS), chemical oxygen demand (COD), and color were investigated. The operating variables were current density of 0–300 A m−2, HRT of 0–30 min, and a coagulant (anionic polyacrylamide (A-PAM)) dosage of 0–30 mg L−1. Daphnia magna was used to test acute toxicity in raw and treated wastewater. Under the operating conditions without added coagulant, maxima of 51%, 88%, 84%, and 99% of conductivity, TSS, COD, and color were removed, respectively, with a HRT of 30 min. The coagulant enhanced removal of all wastewater parameters. Removal maxima of 59%, 92%, 94%, and 98% for conductivity, TSS, COD, and color were observed, respectively, with an optimal dosage of 30 mg L−1 and a shortened HRT of 20 min. The 48 h-LC50 D. magna test showed that the raw wastewater was highly toxic. However, the EC-EF process decreased toxicity of the treated samples significantly, and >70% toxicity reduction was achieved by the EC-EF process with the addition of 15–30 mg L−1 coagulant, HRT of 20 min, and current density of 150–300 A m−2. The pilot scale test (0.3 m3 h−1) shows that the EC-EF process with added coagulant effectively treated textile dyeing wastewater.

Bentonitic clay as adsorbent for the decolourisation of dyehouse effluents

Textile dyehouses generate high volumes of coloured wastewaters, which require convenient treatment in order to avoid water bodies' contamination, adverse effects to aquatic life and risks to human health. The complete decolourisation of such contaminated waters in a cost-effective manner is still a challenge nowadays. This work focuses on the use of a clayey material as a low-cost adsorbent for a basic textile dye (Red 46), commonly used in acrylic fibres dyeing. The bentonitic clay (49% of montmorillonite) presents a considerable (50 cmolc/kg) cationic exchange capacity and a porosity of 10%. Dye adsorption kinetics was successfully described by a pseudo-second order model, resulting an average kinetic constant of 0.23gdyegclay−1min−1. Adsorption equilibrium was reached in 12–24 h and data were successfully fitted to Freundlich and Langmuir equations. The maximum adsorption capacity predicted by the Langmuir model depends on the pH, varying between 217 mg/g at pH 8 and 584 mg/g at pH 9 (25 °C). Increasing the temperature from 25 to 35 °C also led to an increase in adsorbed amounts. In addition to the excellent adsorption performance, the clay showed a great affinity to the dye, indicating high propensity to complete decoulorization of textile dyeing wastewaters. The results obtained in the present work show that a natural, readily-available and cheap material i.e. a bentonitic clay can be used as an effective and environmentally-friendly adsorbent for basic dyes.

Advanced treatment of textile dyeing wastewater through the combination of moving bed biofilm reactors and ozonation

ABSTRACTA four-stage lab-scale treatment system [anaerobic moving bed biofilm reactor (MBBR)-aerobic MBBR-ozonation-aerobic MBBR in series] was investigated to treat textile dyeing wastewater. The MBBRs were operated in a continuous horizontal flow mode. To determine the optimum operating conditions, the effect of hydraulic retention time (HRT) and ozonation time on pollutant removal were analysed by continuous and batch experiments. The optimum operating conditions were found to be 14 h HRT for both anaerobic and no. 1 aerobic MBBRs, 14 min ozonation time and 10 h HRT for no. 2 aerobic MBBR. The average influent concentrations of chemical oxygen demand (COD), suspended solids (SS), ammonia and colour were 824 mg/L, 691 mg/L, 40 mg/L and 165°, respectively. Under these conditions, the average effluent concentrations of COD, SS, ammonia and colour were 47 mg/L, 15.2 mg/L, 5.9 mg/L and 6.1°, respectively, corresponding to total removal efficiencies of 94.3%, 97.8%, 85.3% and 96.3%, respectively. The final effluent could meet the reuse requirements of textile industry. The anaerobic MBBR process improved the biodegradability of the raw wastewater, while the two aerobic MBBRs played an important role in removing COD and ammonia. The ozonation process enhanced the biodegradability of no. 1 aerobic MBBR effluent, and finally, deep treatment was completed in no. 2 aerobic MBBR. The combined process showed a promising potential for treatment of high-strength dyeing wastewater.

Novel low-fouling membrane bioreactor (MBR) for industrial wastewater treatment

A novel antifouling coating of ultrafiltration (UF) commercial membranes, based on a polymerisable bicontinuous microemulsion (PBM) technique, was developed and tested for the first time in a membrane bioreactor (MBR) using an artificial model textile dye wastewater and compared with a commercial uncoated UF membrane. The results showed that the commercial MBR module faced severe fouling problems whereas the novel coated PBM MBR module reduced the fouling significantly. The analysis of fouling rate using a resistance model confirms that PBM coated membrane has a higher antifouling effect. The antimicrobial properties of the PBM membrane contributed by polymerisable cationic surfactant acryloyloxyundecyltriethylammonium bromide (AUTEAB) guaranteed an anti-biofouling effect preventing the growth of microorganisms on the membrane surface. In addition, the PBM MBR module showed 10±1% higher blue dye removal efficiency and a similar rate of COD removal efficiency of about 95±1% compared to commercial module. However, water permeability was slightly lower due to extra resistance of the PBM coating. Root mean squared (RMS) roughness measurement and analysis of AFM images confirmed that the stable novel membrane coating still existed and showed antimicrobial effect even after 105 days of operation. The results obtained demonstrated the potential of the low fouling PBM membrane.

Toxicity Appraisal of Untreated Dyeing Industry Wastewater Based on Chemical Characterization and Short Term Bioassays.

Characterizing wastewaters only on a chemical basis may be insufficient owing to their complex nature. The purpose of this study was to assess toxicity of textile dyeing wastewater based on analytical techniques and short term toxicity based bioassays. In this study, screening of the fractionated wastewater through GC-MS showed the presence of phenols, phthalic acid derivatives and chlorpyrifos. Metal analysis revealed that chromium, arsenic and mercury were present in amounts higher than the wastewater discharge limits. Textile dyeing wastewater was found to be highly mutagenic in the Ames test. DNA damage in sheep lymphocytes decreased linearly with an increase in the dilution of wastewater. MTT assay showed that 8.3 percent v/v wastewater decreased cell survival percentage to 50 %. It can be concluded from this study that short term toxicity tests such as Ames test, in vitro comet assay, and cytotoxicity assays may serve as useful indicators of wastewater pollution along with their organic and inorganic chemical characterizations.