Dye Bath Wastewater Research Articles

Enhanced filtration membranes with graphene oxide and tannic acid for textile industry wastewater dye removal

ABSTRACT A novel modification technique employing a layer-by-layer (LbL) self-assembly method, integrated with a pressure-assisted filtration system, was developed for enhancing a commercial polyethersulfone (PES) microfiltration (MF) membrane. This modification involved the incorporation of tannic acid (TA) in conjunction with graphene oxide (GO) nanosheets. The effectiveness of the LbL method was confirmed through comprehensive characterization analyses, including ATR-FTIR, SEM, water contact angle (WCA), and mean pore size measurements, comparing the modified membrane with the original commercial one. Sixteen variations of PES MF membranes were superficially modified using a three-factorial design, with the deposited amount of TA and GO as key factors. The influence of these factors on the morphology and performance of the membranes was systematically investigated, focusing on parameters such as pure water permeability (PWP), blue corazol (BC) dye removal efficiency, and flux recovery rate (FRR). The membranes produced with the maximum amount of GO (0.1 mg, 0.55 wt%) and TA as the inner and outer layers demonstrated remarkable FRR and significant BC removal, exceeding 80%. Notably, there was no significant difference observed when using either 0.2 (1.11 wt%) or 0.4 mg (2.22 wt%) in the first layer, as indicated by the Tukey mean test. Furthermore, the modified membrane designated as MF/TA0.4GO0.1TA0.4 was evaluated in the filtration of a simulated dye bath wastewater, exhibiting a BC removal efficiency of 49.20% and a salt removal efficiency of 27.74%. In conclusion, the novel PES MF membrane modification proposed in this study effectively enhances the key properties of pressure-driven separation processes.

Green iron particles in textile and dyebath wastewater decolorization

Green iron particles in textile and dyebath wastewater decolorization

Electrocoagulation of Disperse Dyebath Wastewater: Optimization of Process Variables and Sludge Production

Electrocoagulation of Disperse Dyebath Wastewater: Optimization of Process Variables and Sludge Production

Water recovery from textile bath wastewater using combined subcritical water oxidation and nanofiltration

Abstract In this study, textile dye bath wastewater was treated by subcritical water oxidation (SCWO) and pressure-driven membrane process. 54.5% of chemical oxygen demand (COD) reduction and 91.7% of color removal were obtained using eco-friendly SCWO method in the presence of H2O2. Box-Behnken design was performed to optimize the SCWO process and precision of the models were evaluated by ANOVA. Two different nanofiltration (NF270 and NF90) membranes were tested before and after SCWO pretreatment. The effect of membrane type (NF270 and NF90) and transmembrane pressure (10, 20, 30, 40 bar) were studied to improve COD reduction and colour removal efficiency. The results showed that steady-state permeate flux increased from 6.6 to 23.5 L/m2.h for NF270 at 30 bar and from 10.0 to 12.4 L/m2.h for NF90 membrane at 40 bar when SCWO was applied as the pretreatment method. The results depicted that SCWO pre-treatment increased the permeate flux almost 2–3 fold. COD was also tested for all permeates and the highest COD reduction efficiency was obtained for SCWO + NF90 combined process. The highest COD reduction and color removal efficiencies were obtained as 96.1% and 99.3%, respectively, for combined SCWO + NF90 process at 40 bar. The proposed combined SCWO + NF90 process was successfully used to recover wastewater from textile dye bath wastewater.

Electrochemical Treatment of Textile Dye Bath Wastewater Using Activated Carbon Cloth Electrodes

The performance of electrooxidation (EO) treatment using activated carbon cloth (ACC) electrodes on textile dye bath wastewater was investigated. ACC electrode pairs were used as anode/cathode for EO experiments. The effect of current density (50–150 A/m2), operating time (0–90 minutes), and solution pH (6-11) were tested for removal of chemical oxygen demand (COD), color, and chloride, as well as the changes in conductivity. 95.5% COD and color removal efficiencies were obtained at current density (CD) of 100 A/m2 at solution pH of 10 for 90 minutes. Moreover, the chloride concentration decreased from 4254 to 35.5 mg/L and solution conductivity decreased from 160 to 131 mS/cm at the same conditions. Operating cost of the EO process was calculated to be 3.13 US$/m3 for 36 kWh/m3 energy consumption. The results indicated that the EO process with ACC electrodes achieved high pollutant removal from textile dye bath wastewater.

Decolorization and COD removal from synthetic and real textile dye bath wastewater containing Reactive Black 5

Decolorization and COD removal from synthetic and real textile dye bath wastewater containing Reactive Black 5

Treatment of reactive dyebath wastewater by electrocoagulation process: Optimization and cost-estimation

Reactive dyestuff is commonly used in the textile industry. Reactive dyebath wastewater (RDW) was treated with a batch, monopolar, parallel lab scale electrocoagulation process (EC) having 0.042 m2 effective electrode area. The effects of process parameters, such as initial pH, current density and electrolysis period on COD and color removal efficiency, were investigated by using response surface methodology (RSM). At the optimal conditions, 85.8% color and 76.9% COD removal were obtained with 1.84 €/m3 operating cost for Al electrode, while 92.0% decolorization and 80.9% COD removal were obtained with 1.56 €/m3 operating cost for an iron electrode. The iron electrode was found superior to aluminum as a sacrificial anode material in terms of COD and color removal with low cost. The cost of electrical energy, electrode, and chemical consumptions for electrocoagulation were considered to find an optimum and feasible solution. As a result, the operating cost consists of approximately 2% for energy, 28% for electrode and 70% for chemical consumption for both electrodes. Based upon the data, it is clearly seen that operating cost covers mostly for HCI to adjust pH due to the high pH and alkalinity of RDW, which was neglected in many studies. The first-order reaction kinetics with a higher slope for the color were well fitted, resulting in faster color removal than that of COD for both electrodes.

H3PO4-activated sawdust and rice husk as effective decolorizers for textile wastewater containing Reactive Black 5

Textile wastewater contains significant amounts of dyes and chemicals, which makes it very difficult to be treated. Reactive Black 5 is one of the most widely used azo dyes that cause severe impact on environment and aquatic life. Activated carbons are known for their high adsorption capacities, and the objective of the current study was to prepare an effective low-cost adsorbent. H3PO4 acid-activated sawdust and rice husk which were prepared using a simple and low-cost method successfully adsorbed Reactive Black 5 (RB 5) in hypersaline synthetic and real textile dye bath wastewaters. SEM analysis of activated carbon made from these two materials showed an enhanced pore structure. 0.10 g of activated sawdust carbon decolorized 88, 97 and 75% of neat RB 5 solution, synthetic textile wastewater and real textile dye bath wastewater, respectively. RB 5 adsorption is pH dependent, and low pH facilitates the dye adsorption. Langmuir and Freundlich isotherm models were used to analyze the equilibrium adsorption data, and only the Langmuir isotherm model shows a good correlation (R2 = 0.99). Kinetic data match well with the pseudo-second-order model, and the calculated rate constants are 6.09 × 10−3 g mg−1 min−1 and 9.88 × 10−3 g mg−1 min−1 for activated carbon of sawdust and rice husk, respectively. Thermodynamic parameters, ΔG0, ΔH0 and ΔS0, for both types of activated carbon show that the adsorption process is favorable, endothermic and spontaneous.

Surface modification of a polyethersulfone microfiltration membrane with graphene oxide for reactive dyes removal

Polyethersulfone microfiltration membranes (mPES) were modified with polyethilenimine (PEI) and graphene oxide (GO) by layer-by-layer self-assembly method via electrostatic interaction using a pressurized filtration system. The high positively charge of PEI allowed it to be easily assembled on the polyethersulfone substrate, and also to receive the negative layer of GO. Several techniques were applied to characterize the modified membranes (i.e. ATR-FTIR, SEM, water angle contact and zeta potential), and proved that the modification was successfully achieved. The effect of PEI and GO concentrations in the modification was investigated, and the best performance of all membranes was achieved with a Blue Corazol (BC) dye rejection of 97.8% and a pure water permeability of 99.4 L m−2 h−1 bar−1. The membrane also presented a flux recovery ratio of >80% after being hydraulically cleaned for 30 min. Moreover, the membrane performance was evaluated in terms of rejection of BC dye in a real dye bath wastewater, and an excellent performance with a maximum rejection rate of 96% was observed. Therefore, the proposed study may provide an efficient alternative to feasible the use of microfiltration membranes, by modifying them, in order to improve its surface characteristics and its filtration capacity, aiming to apply it in the removal of dyes of textile industries wastewater.

Treatment of textile dye bath wastewater with ozone, persulfate and peroxymonosulphate oxidation

Treatment of textile dye bath wastewater with ozone, persulfate and peroxymonosulphate oxidation

Reuse of wastewaters on dyeing of polyester fabric with encapsulated disperse dye

ABSTRACT The textile industry can benefit from the use of microcapsules, both adding value to products through the production of technical or functional textiles and improving the processes in the production chain. Some applications have been widely explored in academic research, but many are not feasible for use in industrial scale. Thus, the aim of this study was to develop consistent and efficient methodologies for the encapsulation of active compounds commonly used in the textile industry, employing materials which are viable for large-scale application. In this study, polyurethane-urea microcapsules were formulated by interfacial polymerization and encapsulated with C.I Disperse Blue 60 for the dyeing of polyester fabric without the use of dispersing agents and other auxiliaries. The dyeing was carried out in a high temperature dyeing machine with a very simple dyebath, in which there are only dissolved dye molecules, microencapsulated dyes and the fabric. Additionally, the dyebath wastewaters were reused on a further dyeing as 100% bathwater and mixed with 50% distilled water. Colorimetric measurements show excellent colour removal in both samples.

Recovery of real dye bath wastewater using integrated membrane process: considering water recovery, membrane fouling and reuse potential of membranes

ABSTRACTIt has been recognized by the whole world that textile industry which produce large amounts of wastewater with strong color and toxic organic compounds is a major problematical industry requiring effective treatment solutions. In this study, reverse osmosis (RO) membranes were tested on biologically treated real dye bath wastewater with and without pretreatment by nanofiltration (NF) membrane to recovery. Also membrane fouling and reuse potential of membranes were investigated by multiple filtrations. Obtained results showed that only NF is not suitable to produce enough quality to reuse the wastewater in a textile industry as process water while RO provide successfully enough permeate quality. The results recommend that integrated NF/RO membrane process is able to reduce membrane fouling and allow long-term operation for real dye bath wastewater.

Green dyeing process of modified cotton fibres using natural dyes extracted from Tamarix aphylla (L.) Karst. leaves

This research work involves an eco-friendly dyeing process of modified cotton with the aqueous extract of Tamarix aphylla leaves. During this process, the dyeing step was carried out on modified cotton by several cationising agents in order to improve its dyeability. The influence of the main dyeing conditions (dye bath pH, dyeing time, dyeing temperature, salt addition) on the performances of this dyeing process were studied. The dyeing performances of this process were appreciated by measuring the colour yield (K/S) and the fastness properties of the dyed samples. The effect of mordant type with different mordanting methods on dyeing quality was also studied. The results showed that mordanting gave deeper shades and enhanced fastness properties. In addition, environmental indicators (BOD5, COD and COD/BOD5) were used to describe potential improvements in the biodegradability of the dyebath wastewater. Further, HPLC was used to identify the major phenolic compounds in the extracted dye.

Adsorption of reactive dye from aqueous solution and synthetic dye bath wastewater by Eucalyptus bark/magnetite composite.

In the present study, Eucalyptus camaldulensis bark/magnetite composite (EBMC) was used for a potential application as a low-cost adsorbent for the removal of Reactive Black 5 (RB5). The adsorption experiments were performed with aqueous solution (RB5 + distilled water) and synthetic dye bath wastewater (SDBW) in order to investigate the potential application of EBMC in the textile industry. The effects of the various parameters, the initial dye concentration, the temperature, the pH, and the EBMC dosage on the adsorption were investigated. It was found that the adsorption capacity of EBMC increases by increasing the RB5 concentration and temperature and by decreasing the dosage of EBMC. 0.8 g EBMC was found to be sufficient for the removal of 250 mg/L RB5 from 150 mL SDBW with ∼85% removal efficiency. The Koble-Corrigan isotherm model described the adsorption process more effectively (R2 = 0.997) than the Langmuir, Freundlich, the Dubinin-Radushkevich and the Jovanovic isotherm models. The Langmuir isotherm predicted a 370.7 mg/g maximum adsorption capacity. The thermodynamic analysis showed that the adsorption of RB5 onto the EBMC was an endothermic process. The multiple linear regression analysis was used in order to determine the cumulative effects of independent variables on the adsorption capacity.

Salinity effects on biodegradation of Reactive Black 5 for one stage and two stages sequential anaerobic aerobic biological processes employing different anaerobic sludge

In this study the effect of NaCl, normally found in dye bath wastewaters employing reactive azo dyes, on the performance of sequential anaerobic–aerobic processes for treatment of Reactive Black 5 (RB5) containing media, with concentration in the range 100–500 mg L−1, was investigated. Three possible scenarios of the sequential anaerobic–aerobic process, namely two stage process and one stage processes employing either anaerobic or activated sludge, were considered. The results showed a statistically significant enhancement of the anaerobic decolourisation efficiency as a result of the addition of 30 g L−1 NaCl to the RB5 containing media for two stage processes and one stage processes employing anaerobic sludge. NaCl at 30 g L−1 concentration also inhibited aerobic colour formation during two stage processes whereas it prevented aerobic decolourisation during one stage processes. HPLC and UV Vis analysis indicated that during anaerobic phase/stage the majority of azo bonds in RB5 molecules cleave whereas the hydrophobicity/MW of the resulting dye reduction metabolites decreases. The same analysis revealed partial mineralisation of RB5 reduction metabolites under aerobic conditions. The results of the present work also showed that the effect of salt on anaerobic decolourisation efficiency, TVFA and methane production was dependent on the exposure history of anaerobic sludge.

Fouling of nanofiltration membranes by dyes during brine recovery from textile dye bath wastewater

Abstract The present investigation aims at identifying the molecular properties of the dye which control membrane fouling during nanofiltration. Three negatively charged molecules, namely Acid red 87, Direct blue 53 and Acid black 1 and three positively charged molecules, namely Azure A, Basic blue 9 and Basic green 4 are investigated. Dye molecules of 50 mg/L dissolved in 2000 mg/L of NaCl were subjected to nanofiltration using NF 270 membrane (Dow Filmtec with an isoelectric point of 3.3) at pH-3, pH-7 and pH-10. The flux decline, salt rejection and dye rejection were measured using Sterlitech cross flow cell (CF042) with an active membrane surface area of 14.6 × 10−4 m2. Flux decline due to membrane fouling was also calculated by measuring pure water flux after washing the fouled membrane with water at the same pH for 30 min. These results indicate electrostatic interactions between the charged dye molecules and the membrane charge, which depend on the pH. Strong sulfonic acid containing dye molecules (Direct blue 53 and Acid black 1) do not get adsorbed on the membrane surface. High flux rate and dye rejection were noticed in all the three pH media investigated for these dyes. Weak carboxylic acid (Acid red 87) shows strong flux decline and membrane fouling in acidic pH. Positively charged dye molecules with relatively low molecular weights, exhibit strong fouling effect in neutral as well as alkaline pH. The effects of molecular-membrane electrostatic interactions and acid–base interactions on membrane fouling are highlighted in this work along with the molecular size effect.

Textile dyebath wastewater decolorization by electrolytic processes: response surface optimization using IV-optimal design

The aim of the present study is to investigate the potential of electrolytic process on textile dyebath dump wastewater (sulfate concentration ~30 g/L) collected from the cotton fabric dyeing process to remove color and COD concentration. Four different electrode combinations were tested i.e. stainless steel–stainless steel, iron–iron, aluminum–aluminum, and iron (anode)–aluminum (cathode) for best removal efficiency and minimum power consumption along with sludge generation rate. The significant process parameters (voltage/current density and treatment time) were optimized for real industrial wastewater using response surface methodology approach. COD removal efficiency and color removal efficiency were taken as two responses. The best electrode combination was Fe–Al to achieve 75% COD removal efficiency and 91% color removal efficiency. The optimized process conditions are 7.6 V (1242 A/m2) and 14 min treatment time consuming 59 kWh/kg of COD removal with sludge generation rate of 24.1 g/L.

Color removal of Remazol® dyebaths wastewater by UV/H2O2 does not decrease TOC, BOD/COD, and toxicity of the effluent

The present paper aimed at treating the dyebath wastewater of a textile industry by the UV/H2O2 process, mainly to remove color due to reactive Remazol® dyes (Chemical Oxygen Demand [COD] 600 mg O2 L–1; Biochemical Oxygen Demand [BOD] 220 mg O2 L–1; Total Organic Carbon (TOC) 310 mg C L–1). Experimental designs were performed to assess the effects of variables (initial pH, temperature, and initial [H2O2]) and optimize treatment conditions. Those were: initial pH = 11, temperature (T) = 50°C, and initial [H2O2] = 3.1 × 10–4 mol L–1. The response variables were color removal and residual [H2O2]. After two hours of irradiation, color removals of approximately 80 and 75% for UV/H2O2 and direct photolysis were respectively achieved. BOD/COD ratios, TOC, and COD analyses showed no significant changes. Acute ecotoxicity tests, using lettuce (Lactuca sativa) seeds, showed a slight increase in the ecotoxicity of the treated wastewater, for both processes. So, they are not recommended for treating this kind of wastewater.

Techno-economic analysis of textile dye bath wastewater treatment by integrated membrane processes under the zero liquid discharge approach

The present study was intended to determine the usefulness of the zero liquid discharge ( ZLD) approach in treating textile dye bath wastewater via integrated membrane processes. These processes included various combinations of ultrafiltration (UF), loose nanofiltration (NF 1), tight nanofiltration (NF 2) and reverse osmosis (RO). The technological and economic performance of four scenarios (UF/NF 2 ( S (I)), NF 1/NF 2 ( S (II)), NF 1/RO ( S (III)) and UF/NF 2/RO ( S (IV))), each followed by membrane distillation (MD), were comparatively analysed. The factors considered were capital and operating costs, revenues, benefit/cost (B/C) ratios and pay-back times. The last two scenarios, those including RO, provided the best effluent quality at the end of the pressure-driven membrane filtration process. However, these scenarios were not the most economical options because of the decreased benefits of recycling soda ash and NaCl obtained from the treated wastewater. The unit treatment costs of the scenarios were 1.37, 1.38, 2.16 and 2.01 $/m 3 of influent for S (I), S (II), S (III) and S (IV), respectively, with return periods of 0.87, 0.91, 2.07 and 1.51 years. The best technological and economic performance was estimated for S (I) and S (II), as indicated by the B/C ratios 3.58 and 3.55, respectively. At the break-even point of 15 years, S (I) required an incineration cost of 77.5 $/m 3 of MD concentrate, whereas the corresponding costs associated with the other three scenarios were estimated to be 75.7, 43.0 and 35.5 $/m 3 of MD concentrate, respectively. It was finally concluded that the ZLD approach is most useful in processing textile dye bath waste and recycling treated wastewater. This process is both technically feasible and economically viable, as indicated by the high B/C ratio. However, the unit incineration cost associated with the concentrate would limit the return period of the investment, and the success of this method would also depend principally on the real volume of MD processed due to its large contribution (70–90%) to the B/C ratio.

Recycling of Woven Fabric Dyeing Wastewater Practiced in Perundurai Common Effluent Treatment Plant

Textile dyeing industries in Erode and Tirupur district of Tamilnadu (India) discharge effluents ranging between 100 and 200m³/t of production. Dyeing is performed by Jigger or advanced Soft Flow reactor process. Coloring of hosiery fabric takes place in the presence of high concentration of sodium sulphate or sodium chloride (30 – 75 kg/m³) in dye solutions. Wash water and dye bath waste water are the process effluents of dyeing industry which are collected separately and follow the advanced treatment for maximum recycling of recovered waters.Wash water is treated using a sequence of physicochemical and biological unit process, the waste water is passed into ultrafiltration (UF), two stages reverse osmosis (RO) membrane system where the permeate is reused for processes. The rejects about 10 – 12 % of the inlet volume is subject to reverse osmosis for sent to evaporators. Dye bath water after treating, the permeate is used in process for dye bath preparation and the reject of about 20 – 25% is sent to multi effect evaporator / solar evaporation pond (SEP). The final rejects from reverse osmosis system is directed to multi effect evaporator system where condensed waters are recovered. The removal of Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) and Chloride are in the range of 82 – 97%, 90 – 97% and 78 – 97% respectively. This study was carrier out Common Effluent Treatment Plant (CETP), Perundurai, SIPCOT, Erode district.