Influent Dye Concentration Research Articles

Treatment of textile industry effluents with up‐flow anaerobic sulfidogenic reactor

AbstractBACKGROUNDDyes present in textile wastewater can pose various environmental problems, including toxicity, carcinogenicity and mutagenicity, when released into receiving environments. Sulfidogenic bacteria play a crucial role in wastewater treatment by reducing sulfate and producing sulfide through the utilization of organic compounds in water. The resulting sulfide often transfers its electrons to another electron acceptor. This study focused on the treatment of real textile wastewater using an up‐flow sulfidogenic column bioreactor.RESULTSThe reactor was acclimated to sulfate‐reducing conditions when influent chemical oxygen demand and sulfate concentrations were 1742 and 2000 mg L−1, respectively. Subsequently, a gradual transition was made from sulfate‐reducing conditions to dye‐reducing conditions. Throughout the study, the hydraulic retention time was maintained at 1 day.CONCLUSIONThe influent dye concentration was 2722 Pt‐Co, and an impressive dye removal efficiency of approximately 90 ± 2% was achieved. This corresponds to a removal rate of 2450 Pt‐Co L−1 day−1. Although the sulfide concentration in the reactor decreased in the last period, investigating the extent to which this sulfide participates in the dye removal may expand the use of sulfidogenic reactors in the treatment of real textile industry wastewater. © 2024 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Refractory azo dye wastewater treatment by combined process of microbial electrolytic reactor and plant-microbial fuel cell

An innovative design of microbial electrolytic reactor (MER) coupled with Ipomoea aquaticaForsk. plant microbial fuel cell (IAF-PMFC) was developed for azo dye wastewater treatment and electricity generation. This study aims to assess the sequential degradation of azo dye and the feasibility of energy self-sufficiency in the MER/IAF-PMFC system. The decomposition of azo dye into aromatic amines and dye decolorization occurred in the MER at high hydraulic loading of 0.28 m3/(m2·d), while dye intermediates were mainly mineralized in the IAF-PMFC at low hydraulic loading of 0.06 m3/(m2·d). The final decolorization efficiency and COD removal of the combined system reached 99.64% and 92.06% respectively, even at influent dye concentration of 1000 mg/L. The effects of open/closed circuit conditions, presence/absence of aquatic plant and different cathode areas on the performance of the IAF-PMFC for treating the effluent of the MER were systematically tested, and the results showed that closed-circuit condition, plant involvement and larger cathode area were more beneficial to decolorization, detoxification and mineralization of dye wastewater, bioelectricity output, plant growth and photosynthetic rate. The power consumption by the MER was 0.0163 kWh/m3 of dye wastewater, while the highest power generation of the IAF-PMFC reached 0.0183 kWh/m3. The current efficiency of the MER for dye decolorization was as high as 942.83%, while the maximum coulombic efficiency of the IAF-PMFC for intermediates metabolism was only 6.30%, which still had much space of bioelectricity generation promotion. The MER/IAF-PMFC technology can simultaneously realize refractory wastewater treatment and balance of electricity production and consumption.

Selective adsorption of anionic dye from wastewater using polyethyleneimine based macroporous sponge: Batch and continuous studies

Dyes are well known for their hazardous impacts on public health and the environment. Dye removal using monolithic adsorbents is an attractive approach for industrial applications and process design owing to their utilization in both static and dynamic adsorption experiments. In the present work, polyethyleneimine (PEI) based macroporous monolithic sponge (S100) was engineered by ice-templating method and used as an adsorbent. Both batch and continuous operations for dye removal were studied. The effect of various parameters such as pH, adsorbent amount, flow rate, influent dye concentration, and adsorbent bed height on adsorption performance of S100 was studied and modelled using Langmuir/Freundlich isotherms for static operations and Adam-Bohart/Thomas model in packed-bed column experiments. Under optimum conditions, the adsorbent showed a remarkably higher adsorption capacity towards CR (1666.67 mg/g), which is considerably higher than most PEI-based adsorbents. Amine groups in S100 offered exceptional selectivity for anionic Congo red (CR) against cationic Methylene blue (MB) dye (separation factor of 208 and 87 in absence and presence of sodium chloride, respectively). It can be easily regenerated in alkaline medium without a significant loss in percent adsorption capacity and shows good thermal and mechanical stability. Notably, in column studies, a relatively smaller percentage of unused bed height (32.3%) was observed with higher dye uptake for 16 mg S100 at flow rate 10 mL/h and inlet concentration 300 mg/L. Thus, the adsorbent displays an outstanding physiochemical characteristic, excellent selectivity for anionic dye, ease of regeneration and high adsorption performance in both batch and continuous studies.

Adsorptive column studies for removal of Reactive Blue 4 dye using dry cells of Rhizopus oryzae (MTCC 262)

The biosorption potential of dry biomass of Rhizopus oryzae (MTCC 262) in removing a textile dye Reactive Blue 4 from dye contaminated wastewater using up-flow packed-bed column reactor has been studied. The impact of operating parameters like flow rate of dye solution, bed height of column and concentration of dye in the feed solution on the removal potential has also been studied. The Adam-Bohart Model, Yoon-Nelson Model and Thomas model are used for the analysis of experimental data. Dye removal of 71.81% is obtained using dry biomass at flow rate of 2 mL min-1of dye solution, bed height of 15 cm and influent dye concentration of 200 mg L-1. Adsorbed dye can be successfully recovered from dry R.oryzae (MTCC 262) biomass of packed bed column reactor by running 1 (N) NaOH solution. Results demonstratesignificant reduction in Reactive Blue 4 concentration after the biosorption process.

Degradation of azo dye wastewater by the combination process of 3D BER and CW-MFC

The treatment of azo dye wastewater has become a hot issue in the area of water pollution control. In this paper, a novel combined process of constructed wetland-microbial fuel cell (CW-MFC) and three dimensional biofilm electrode reactor (3D BER) was carried out for treatment of reactive brilliant red X-3B dye wastewater. Decolorization rate, COD removal and electricity generation in the combination process were studied, and the main factors affecting the system’s performance were also investigated. The results showed that the decolorization rate of combination process (3D BER-CW-MFC) was over 96%, and closed-circuit CW-MFC had better decolorization effect than open-circuit CW-MFC. COD removal rate of the combination process was far higher than the 3D BER and CW-MFC operated alone (78.9%∼90.8% and 50.6%∼66.2%, respectively). With the increase of influent dye concentration in the 3D BER, Cell voltages of the CW-MFCs all increased firstly and then decreased. The cell voltage reached the maximum at influent dye concentration of 600 mg L-1, and then decreased by 6.42%∼14.34% after the dye concentration increased to 1000 mg L-1. In addition, cell voltage could be enhanced by increasing the cathode area of CW-MFCs, due to improved cathode potential and reduced total internal resistance of the system.

Textile sludge–sawdust chemically produced activated carbon: equilibrium and dynamics studies of malachite green adsorption

Textile sludge–sawdust chemically produced activated carbon (SSAC) was used in equilibrium and dynamics adsorption of malachite green (MG). The effects of concentration in equilibrium, and influent flow rate (15–30 mL/min), initial concentration (20–80 mg/L) and bed height (2–6 cm) in dynamics mode were investigated. SSAC with surface area of 979 m2/g shows an outstanding maximum capacity of malachite green at 530 mg/g. In adsorption dynamics, the breakthrough time and bed capacity increased with increasing bed height, and decreasing flow rate and influent dye concentration. Bohart-Adams, Thomas, Yoon-Nelson and Clark models were applied to describe the column breakthrough, dynamics behaviour and adsorption mechanisms. The breakthrough curves were best fitted by Yoon-Nelson model at the experimental conditions. The maximum bed capacity was reported to be 565 mg/g. SSAC is an effective adsorbent for MG removal from aqueous phase.

Nano silver chloride and alginate incorporated composite copolymer adsorbent for adsorption of a synthetic dye from water in a fixed bed column and its photocatalytic reduction

Several functional adsorbents were synthesized by copolymerizing acrylic acid (AA) and hydroxyethyl methacrylate (HEMA) in the presence of sodium alginate in water. Silver chloride nano particles (AgClNP) were also incorporated in the polymer matrix by coprecipitation method. The resulting composite type functional adsorbents were used for adsorption of a synthetic dye, namely, brilliant cresyl blue (BCB) from water in batch and in continuous mode in a fixed bed column. The formation of the adsorbent, AgClNP and its incorporation in the polymer matrix were characterized while pH sensitivity was studied with pH reversibility test and point zero charge (PZC) study. The network parameters were also determined. The synthesis and process parameters were optimized with a central composite design (CCD) of response surface methodology (RSM) with respect to adsorption capacity as response in a batch study and the adsorbent showing optimum performance was further used for column study in a fixed bed. The effect of bed height, influent dye concentration and volumetric flow rate on dye adsorption were studied and the adsorption data showed close fitting to Adam-Bohart and Clark model. The photocatalytic degradation of the heterocyclic dye by the AgClNP incorporated adsorbent in the presence of UV radiation was also studied.

Evaluation of the hydraulic and hydrodynamic parameters influencing photo-catalytic degradation of bio-persistent pollutants in a pilot plant

A kinetic study on the photo-catalytic degradation of bio-persistent micro-pollutants, as methyl red and methylene blue dyes, was carried out on an innovative unit by changing the hydraulic and hydrodynamic parameters of the system. The catalyst (TiO2, anatase) was embedded into a cement matrix and deposited at the bottom of a channel to activate the UVB photo-degradation reactions. The influence of the catalyst dosage, substrate concentration c0, and pH was evaluated on the degradation rates. The optimum catalytic dose was obtained at 0.79 g/cm3 while the best results were observed at 0.7 mg/L influent dye concentration. The pH of the solution influenced the sorption phenomena because the charge of the substrates functional groups as well as the charge of the catalyst surface were affected by this parameter. Different unit geometries, hydraulic loads (hw) and gradients (i) affected speed and flow-rate (Q) of the liquid phase and, as a consequence, the irradiated retention times (Irt) of the substrates to the UV/TiO2 system. Kinetics resulted faster at increasing flow-rates of the liquid flowing through the channel, constant the hydraulic load, whereas the increase in the hydraulic load did not improve the performances. Finally, degradation rates slightly decreased after the increase in the hydraulic gradient of the channel.

Biotreatment of malachite green from aqueous solution and simulated textile effluent by growing cells (batch mode) and activated sludge system

Textile dyes such as malachite green are common contaminants in wastewater which are persistent in environment and also toxic to living organisms. In this study, live, growing cells of our patented bacterial strain, Bacillus cereus M116 – were used for bioremediation of one representative textile dye, malachite green – first in batch process to standardize the environmental parameters for optimum bioremediation – then bioremediation of the representative dye from synthetic dye solution along with subsequent COD removal in aerated stirred tank, using activated sludge system (containing B. cereus M116, as dominant species) – under standardized conditions from batch process. Finally, the optimized activated sludge system was applied for bioremediation of dye and COD removal from simulated textile effluent. The batch experiments provided the benchmark information regarding the environmental parameters that could influence the bioremediation of malachite green viz., pH 7.0, 2% (v v−1) of inoculum, most effective initial dye concentration of 50 mg L−1, minimum contact time of 20 h and incubation conditions – 30 °C, under shaking 120 rpm. The activated sludge system was acclimatized with cultured B. cereus M116 broth (cell concentration 1.6 g L−1). Bioremediation of dye was carried out following acclimatization (average MLSS in the range 3520–4020 mg L−1). In the activated sludge system, a maximum of 96% dye removal and 79% COD removal were recorded at 50 mg L−1 influent dye concentration and 0.014 h−1 dilution rate which provided a hydraulic retention time of 72 h. The studied activated sludge system was also found efficient in bioremediation of malachite green (96%) from simulated textile effluent along with removal of COD. Thus, activated sludge system can be utilized as a cheap and efficient method of bioremediation for continuous treatment of large-scale wastewaters.

Fixed-bed system for adsorption of anionic acid dyes from binary solution onto quaternized kenaf core fiber

Water pollution due to the effluents from textile industries causes serious concern around the world. During the coloration process, the excess synthetic dyes are discharged into the wastewater stream. In the present research, kenaf core fiber (KCF) residue was chemically modified with (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC) to alter the surface properties and increase the surface area to develop more active sites that capture anionic dyes from aqueous solution. Fixed-bed adsorption studies were conducted to investigate the performance of using quartenized kenaf core fiber (QKCF) as an adsorbent for the removal of anionic acid dyes from a binary system. The effects of operational parameters, including inlet dye concentration, flow rate, and bed height, were studied in a fixed-bed column system, while other process parameters were fixed, i.e. pH and temperature at 7.5 and 27 ºC, respectively. The fixed-bed column performed better with lower influent dye concentration, less flow rate of the influent, and a higher adsorbent bed depth. Overall, the present study showed that QKCF is a potential adsorbent for anionic dye removal from aqueous solutions in a fixed-bed column system.

Continuous removal of malachite green by calcium alginate immobilized Bacillus cereus M116 in packed bed column

Abstract Continuous removal of malachite green from synthetic dye solution (pH 5.0) was studied with Bacillus cereus M116 immobilized in calcium alginate (3%) using a packed bed column reactor operated at 30 °C. The experiments were conducted to study the effect of important parameters such as flow rate, bed height and influent dye concentration on the dye removal process. Maximum dye removal ( 74.7 ± 0.4 % ) was observed at 2 mL/min flow rate, 30 cm bed height and 100 mg/L influent dye concentration. The Adam–Bohart model, Yoon–Nelson model and Thomas model were employed to determine characteristic parameters such as saturation concentration (N0), kinetic rate constant (KAB, KY N, KTh), maximum biosorption capacity (q0), and the time required for 50% adsorbate breakthrough ( τ ), which are all useful for process design. Maximum biosorption capacity of 37.21 mg/g was obtained at optimum conditions. Experimental data fitted well with Adam–Bohart model at initial part of the breakthrough curve.

Continuous adsorption study of congo red using tea waste in a fixed-bed column

In this paper, continuous fixed-bed studies were carried out to investigate the feasibility of using tea waste (TW) as a low-cost adsorbent for the removal of Congo red (CR) from aqueous solution. Effects of various parameters, such as mass of the adsorbent, flow rate, influent dye concentration, and initial pH were investigated. It was found that the amount of the column adsorption capacity was at about 3 mg/g. Three commonest models, namely Adams–Bohart, Thomas, and Yoon–Nelson models have been employed to predict the adsorption breakthrough curves of CR onto TW. The Adams–Bohart model satisfactorily predicts the initial parts of the adsorption process with the correlation coefficient at about 0.9. The Thomas and Yoon–Nelson models were found to be in reasonable agreement with the experimental data. In addition, the bed depth service time (BDST) model was applied at different bed depths. The results revealed that the experimental data greatly described using BDST model. It was concluded that the fixed-bed adsorption column with TW adsorbent can be used as a wastewater treatment for the removal of CR.

Effect of Anaerobic Azo Dye Reduction on Continuous Sludge Digestion

Effect of continuous feeding of a reactive azo dye, reactive orange 107, and its hydrolyzed form (HRO107), on a conventional anaerobic digester was investigated in this study together with observation of change in microbial community. Laboratory‐scale digesters were fed with waste activated sludge and azo dye for 575 days continuously. The influent concentrations of reactive azo dye were between 200 and 3200 mg/L. The digester performance was not adversely affected by azo dye and its reduction metabolites throughout the study. A HRO107 concentration with 3200 mg/L was not inhibitory for the digester performance after prolonged exposure. The dye removal efficiencies were between 95 and 99% most of the time of operation implying that dye removal efficiency was not affected by variations in organic loading rate or influent dye concentration. Sulfate‐reducing bacteria may increase in the digester but did not cause any toxicity due to hydrogen sulfide formation after prolonged feeding.

Lignocellulosic jute fiber as a bioadsorbent for the removal of azo dye from its aqueous solution: Batch and column studies

AbstractThe feasibility of the use of jute fiber for the adsorption of azo dye from an aqueous solution was evaluated with batch and fixed‐bed column studies. The batch studies illustrated that dye uptake was highly dependent on different process variables, namely, the pH, initial dye concentration of the solution, adsorbent dosage, contact time, ionic strength, and temperature. The exothermic and spontaneous nature of adsorption was revealed from thermodynamic study. The equilibrium adsorption data were highly consistent with the Langmuir isotherm and yielded an R2 value of 0.999. Kinetic studies divulged that the adsorption followed a pseudo‐second‐order model with regard to the intraparticle diffusion. In the column studies, the total amount of adsorbed dye and the adsorption capacity decreased with increasing flow rate and increased with increasing bed height and initial dye concentration. Also, the breakthrough time and exhaustion time increased with increasing bed depth but decreased with increasing flow rate and influent dye concentration. The column performances were predicted by the application of the bed‐depth service time model and Thomas model to the experimental data. The virgin and dye‐adsorbed jute fiber was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy analyses. The investigation suggested that jute fiber could be applied as a promising low‐cost adsorbent for dye removal. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Adsorption characteristics of dyes in columns of activated carbon prepared from paper mill sewage sludge

In this work, sludge-based activated carbon (SAC) was prepared from paper mill sewage sludge by physical activation with steam. The adsorption efficiency of SAC to cationic methylene blue (MB) and anionic reactive red 24 (RR 24) from aqueous solutions was investigated using fixed-bed adsorption column. The effects of influent dye concentration, particle size, adsorbent mass and flow rate on the breakthrough characteristics of the adsorption system were determined. Desorption of dyes on SAC was repeated for several cycles in HCl, NaOH and deionized water. The results showed that breakthrough time and exhaustion time increased with decreasing inlet dye concentration, particle size, flow rate and increasing adsorbent mass. The adsorption capacity of SAC in fixed-bed column was lower than that obtained from equilibrium study. However, the SAC adsorption performance was much better than commercial activated carbon, indicating the enormous potential of SAC for removing dyes. In addition, the lower desorption rate of MB than of RR 24 demonstrated that cationic dye was more stable on SAC.

Use of BDST and an ANN model for prediction of dye adsorption efficiency of Eucalyptus camaldulensis barks in fixed-bed system

In this study, the Bohart and Adams’ model taking into account bed depth, and influent dye concentration was studied to exhibit adsorption process of textile dyes (Basic Blue 41 – BB41 and Reactive Black 5 – RB5) in glass columns using tree barks (Eucalyptus camaldulensis). Adsorption capacity coefficient values are determined using the Bohart and Adams’ bed depth service model. The model indicated that adsorption properties of E. camaldulensis barks conform for tertiary treatment for textile BB41 and RB5 containing wastewaters. An artificial neural network (ANN) based model for determining dye adsorption capability of bed system is also developed. The breakthrough curves of adsorption are also exhibited by this model. Results showed that ANN model could describe present system. Results showed that with the increases of bed height, and the decreases of influent dye concentrations, the breakthrough time was delayed.

Study of malachite green adsorption onto natural zeolite in a fixed-bed column

Natural zeolite was used as adsorbent for adsorption of malachite green (MG) from an aqueous solution in a fixed-bed column. The effect of different conditions, such as coexistent salt, flow rate, bed depth and influent dye concentration were studied. The results showed that coexistent salt did not favor adsorption. Adsorption reached saturation faster with increasing the flow rate and influent MG concentration while it was the advantage of column adsorption with the increase in the zeolite bed. The data were fitted to the Thomas model and Yan model by nonlinear regressive analysis. When the flow rate was 9 ml·min−1 and the influent concentration of MG was 50 mg·L−1, the maximum adsorption quantity reached 23.55 mg·g−1 according to the Thomas model. The Yan model was better than the Thomas model to predict the column adsorption process. Zeolite can be used to remove cationic dye from solution.

Textile Dye Removal in Single-Phase and Two-Phase Anaerobic Biotreatment Systems

This research compares performances of an anaerobic two-phase reactor system and a conventional single-phase reactor system in treatment of a synthetic dye wastewater. The two-phase reactor setup used four anaerobic reactors based on upflow anaerobic sludge blanket technology as acid reactors and an expanded granular sludge bed (EGSB) reactor as a methane reactor. An anaerobic reactor based on EGSB technology constituted the single-phase reactor setup. The reactors were operated at different hydraulic retention times (HRTs). The acid reactors removed up to 67% of the influent chemical-oxygen demand (COD) and 77% of the influent dye or color. An average of 10–25% acidification was achieved, and acetic acid, propionic acid, and butyric acid were the major volatile fatty acids produced in the acid reactors. The organic loading or the influent dye concentration did not have any significant effect on acid production or its speciation. The two-phase system could be operated at a HRT as low as 7.5 h with at leas...

Adsorption characteristics of reactive dyes in columns of activated carbon

Adsorption behaviour of reactive dyes in fixed-bed adsorber was evaluated in this work. The characteristics of mass transfer zone (MTZ), where adsorption in column occurs, were affected by carbon bed depth and influent dye concentration. The working lifetime ( t x ) of MTZ, the height of mass transfer zone (HMTZ), the rate of mass transfer zone (RMTZ), and the column capacity at exhaustion ( q column) were estimated for the removal of remazol reactive yellow and remazol reactive black by carbon adsorber. The results showed that column capacity calculated at 90% of column exhaustion was lower than carbon capacity obtained from equilibrium studies. This indicated that the capacity of activated carbon was not fully utilized in the fixed-bed adsorber. The bed-depth service time model (BDST) was applied for analysis of reactive yellow adsorption in the column. The adsorption capacity of reactive yellow calculated at 50% breakthrough point ( N 0) was found to be 0.1 kg kg −1 and this value is equivalent to about 14% of the available carbon capacity. The results of this study indicated the applicability of fixed-bed adsorber for removing remazol reactive yellow from solution.

Polishing of pretreated dye wastewater using novel sequencing batch reactors

Novel, aerobic sequencing batch reactor technology was tested as a polishing step for anaerobically treated textile wastewater containing dye. Operation cycle times of 6, 8 and 12 hours were studied using discrete phase periods. The SBRs were able to further remove influent dye concentration of as little as 5 mg/L, and remove highly variable loadings of COD and SS to effluent levels of 100 and 20 mg/L respectively.