Effective removal of sulfur dyes from water by biosorption and subsequent immobilized laccase degradation on crosslinked chitosan beads
Introduction
Chitosan is known as a cheap, eco-friendly and efficient biosorbent for pollutant mixtures. In the treatment of textile effluents treatment, it has been widely applied for dye removal and/or decolorization [1]. The amino (–NH2) and hydroxyl (–OH) groups of chitosan serve as the active sites for biosorption. The chemical modification of this water-insoluble material can be done easily because of the presence of these groups [2], [3], [4]. Chitosan is soluble in an acetic acid solution, and its hydrogel beads are precipitated and formed in NaOH solution. The elemental structure of chitosan has no difference after this acidic modification. The chitosan beads (CBs) have a higher adsorption capacity than the raw chitosan flakes.
Laccase has been of interest in recent years for synthesizing various dyes and decolorizing industrial textile effluents [5]. It catalyzes the oxidation of substrates coupled with the reduction of molecular oxygen from water. Laccase was effectively and popularly used for dye removal [6], [7]. Under alkaline conditions, the hydroxide ion causes enzyme inhibition [8]. A decrease or loss in laccase activity occurs when the pH is higher than 6.5. The binding of the OH− ion to the multicopper atoms of laccase breaks down the electron transfer system [9]. In the case of catalytic systems with water-insoluble enzymes, immobilization of the enzymes is a better choice than the free enzymes [10], [11]. Immobilized enzymes can be effectively applied and reused. These enzymes cannot be easily washed away in a continuous system. It was reported that laccase can be readily immobilized onto chitosan via an adsorption method [11]. However, because supports such as CBs are denatured and dissolved in low-pH solutions, CBs cannot be applied without modifications [12]. To protect them from the damage of acidic solutions, cross-linking chitosan with bifunctional groups of glutaraldehyde (GA) was discovered and is generally applied. During the cross-linking process, the aldehyde group (–CHO) of GA binds to the amino group (–NH2) of chitosan. Additionally, GA can form covalent bonds with laccase [11]. The immobilization of laccase with chitosan is achieved via the covalent bonds made by an enzyme and the GA-crosslinking chitosan beads (GA-CBs). In fact, the concentration of GA must be controlled. A high concentration of GA creates a multi-point binding for the laccase with support, which is responsible for the transformation of the dimensional structure of active centers of laccase [13]; therefore, the activity of laccase decreases after immobilization.
The world’s consumption of sulfur dyes has still been high in recent years [14], [15]. Sulfur dye is a highly profitable dye, and thus, the environment is continuously exposed to the negative effects. Although greener methods of sulfur dyeing have been researched and applied recently [16], [17], the use of sulfur dyes on cellulosic fibers with sodium sulfide as an efficient reducing agent is still known to be a traditional and cheap dyeing process [15], [18]. Glucose, Na2S2O4, hydrosulfite, thioglycolic acid, thiosalicylic acid, and sodium bisulfide were seriously considered for the replacement of sodium sulfide [14]. When these chemicals were used, aside from effectively reducing the results, some unwanted disadvantages, such as the change of shades and a poor affinity for cellulose, occurred.
In this study, the GA-CBs were selected as the biosorbents and immobilization supports of laccase for the removal of two sulfur dyes (sulfur blue 15, SB15 and sulfur brown GD, SBGD) from synthetic solutions. There are numerous types of dyes treated by many methods [15]. To the best of our knowledge, this is not really the case for sulfur dyes, although SB15 and SBGD have been widely used in the sulfur dye market. The probable reason is that the simultaneous determination of sulfur dye concentrations in multicomponent mixtures is difficult. We believe that this work is a starting point to examine the removal of sulfur dye mixtures in the laboratory. The effectiveness and economic reasons for successive two-step processes via the recovery of related materials are expected. The main aim of this work was to investigate the partial and overall removal, the best-fit biosorption isotherms in single and binary dye systems, the kinetic constants of enzymatic degradation, and the preference of degradation of individual dye with laccase from Trametes versicolor (T. versicolor).
Section snippets
Dyes and chemicals
The dyes that were used were sulfur blue 15 (SB15, CI 53540, MW 343.3 g mol−1) and sulfur brown GD (SBGD, CI 53210, MW 104.1 g mol−1), which were purchased from the Ningbo New Dragon International Co. (China). Their chemical structures are shown in Fig. 1 [19]. It was noticed that SBGD is also called sulfur brown 4, which is manufactured by coarse cresol, or m-cresol, and sodium polysulfide in 270–275 °C calcination, with or without a copper sulfate monohydrate. Commercial chitosan with an average
Characterization of the CBs, GA-CBs, and LA-GA-CBs
CFE-SEM images of the CBs, GA-CBs, and LA-GA-CBs are shown in Fig. 4. The porous and rough structure of the CBs is easily recognized in Fig. 4a. This structure reveals the high biosorption capability of CBs. Before and after laccase immobilization, the surface structure of GA-CBs clearly changes (Fig. 4b and c). On the surface of GA-CBs, the rippled and rough structure was replaced by a smoother and tighter structure. These images show that a stable polymeric structure of a laccase layer was
Conclusions
The concentrations of SB15 and SBGD in binary mixtures could be simultaneously analyzed via the fourth-order derivative of the UV/visible spectra. Glutaraldehyde-crosslinked chitosan beads (GA-CBs) were efficient biosorbents for the removal of SB15 and SBGD in single and binary systems. The maximum biosorption capacity of single SB15 and SBGD was 0.146 mmol g−1 (30 °C) and 0.437 mmol g−1 (50 °C), respectively, at a pH of 10.5. Additionally, SBGD had a higher biosorption affinity on the GA-CBs than
Acknowledgements
Financial support for this work through grants from the Ministry of Science and Technology, Taiwan (No. 102-2221-E-182-076-MY3) and the Chang Gung Medical Foundation, Taiwan (No. BMRPD81) is gratefully appreciated.
References (46)
- et al.
Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions by adsorption processes using batch studies: a review of recent literature
Prog. Polym. Sci.
(2008) - et al.
Crosslinked chitosan/polyvinyl alcohol blend beads for removal and recovery of Cd(II) from wastewater
J. Hazard. Mater.
(2009) - et al.
Application of chitosan and its derivatives as adsorbents for dye removal from water and wastewater: a review
Carbohydr. Polym.
(2014) - et al.
Production of a laccase from Botrytis cinerea and application for textile phenolic dye decolorization
Energy Procedia
(2013) Application of chitin-and chitosan-based materials for enzyme immobilization: a review
Enzyme Microb. Technol.
(2004)- et al.
Recent developments and applications of immobilized laccase
Biotechnol. Adv.
(2013) - et al.
Use of chemically modified chitosan beads for sorption and enzyme immobilization
Adv. Environ. Res.
(2002) - et al.
Treatment of waters and wastewaters containing sulfur dyes: a review
Chem. Eng. J.
(2013) - et al.
Ecological alternatives to the reduction and oxidation processes in dyeing with vat and sulfur dyes
Dyes Pigm.
(2008) - et al.
Surface chemical analysis of the effect of extended laundering on sulfur black 1 dyed cotton fabric
Dyes Pigm.
(2013)
Modification of crosslinked chitosan beads with histidine and Saccharomyces cerevisiae for enhanced Ni(II) biosorption
J. Taiwan Inst. Chem. Eng.
Laccase immobilization on radiation synthesized epoxy functionalized polyethersulfone beads and their application for degradation of acid dye
Polymer
Adsorption of basic dyes from single and binary systems onto bentonite: simultaneous analysis of Basic Red 46 and Basic Yellow 28 by first-order derivative spectrophotometric analysis method
J. Hazard. Mater.
Removal of binary azo dyes from water by UV-irradiated degradation in TiO2 suspensions
J. Hazard. Mater.
Tannic acid interferes with the commonly used laccase-detection assay based on ABTS as the substrate
Biochimie
Immobilization of commercial laccase onto green coconut fiber by adsorption and its application for reactive textile dyes degradation
J. Mol. Catal. B Enzym.
Reversible immobilization of laccase to poly(4-vinylpyridine) grafted and Cu(II) chelated magnetic beads: biodegradation of reactive dyes
Bioresour. Technol.
Biodegradation of textile dyes by immobilized laccase from Coriolopsis gallica into Ca-alginate beads
Int. Biodeterior. Biodegrad.
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding
Anal. Biochem.
Prediction of multicomponent adsorption equilibrium data using empirical correlations
Chem. Eng. J.
Biosorption of Acid Black 172 and Congo Red from aqueous solution by nonviable Penicillium YW 01: Kinetics, equilibrium isotherm and artificial neural network modeling
Bioresour. Technol.
Synergistic biosorption between phenol and nickel (II) from binary mixtures on chemically and biologically modified chitosan beads
Chem. Eng. J.
Simultaneous removal of Cr(VI) and phenol from binary solution using Bacillus sp. immobilized onto tea waste biomass
J. Water Process Eng.
Cited by (104)
In-silico and in-vitro targeting of organic dye pollutants from synthetic and real wastewater by the hierarchically self-assembled laccase@bismuth phosphate hybrid nanorods
2024, Journal of Environmental Chemical EngineeringFabrication of protonated chitosan/montmorillonite catalyst for hydrogen production via sodium borohydride in the optimum methanol/propylene glycol mixture
2024, International Journal of Hydrogen EnergyA novel environmental friendly and sustainable process for textile dyeing with sulphur dyes for cleaner production
2024, Chemical Engineering JournalA comparative study of single and bi-doped Co<inf>3</inf>O<inf>4</inf> nanocatalysts for the photodegradation of methyl orange dye
2023, Journal of Molecular StructureSynergistic treatment of textile wastewaters using spent diatomaceous earth loaded with laccases: A cost-effective and eco-friendly approach
2023, Journal of Water Process EngineeringTextile dyes effluents: A current scenario and the use of aqueous biphasic systems for the recovery of dyes
2023, Journal of Water Process Engineering