Removal Of Triphenylmethane Dyes Research Articles

Removal of triphenylmethane dyes by Streptomyces bacillaris: A study on decolorization, enzymatic reactions and toxicity of treated dye solutions.

This study revealed Streptomyces bacillaris as an efficient biological agent for the removal of triphenylmethane (TPM) dyes. The isolate decolorized Malachite Green (MG), Methyl Violet (MV), Crystal Violet (CV), and Cotton Blue (CB) effectively. S. bacillaris in the treated dye solutions were analyzed for enzyme production, and the cell biomass was observed for functional groups and cell morphology. The treated dye solutions were also analyzed for degraded compounds and their toxicity. Results revealed high decolorization activities for MG (94.7%), MV (91.8%), CV (86.6%), CB (68.4%), attributed to both biosorption and biodegradation. In biosorption, dye molecules interacted with the hydroxyl, amino, phosphoryl, and sulfonyl groups present on the cell surface. Biodegradation was associated with induced activities of MnP and NADH-DCIP reductase, giving rise to various simpler compounds. The degraded compounds in the treated dyes were less toxic, as revealed by the significant growth of Vigna radiata in the phytotoxicity test. There were no significant changes in cell morphology before and after use in dye solutions, suggesting S. bacillaris is less susceptible to dye toxicity. This study concluded that S. bacillaris demonstrated effective removal of TPM dyes via biosorption and biodegradation, rendering the treated dyes less toxic than untreated dyes. Findings in this study enabled further explorations into the potential application of lesser-known actinobacteria (i.e. Streptomyces sp.) for dye removal.

Selective Raman detection and photocatalytic degradation of triphenylmethane dyes based on Ag nanoparticles anchored on the flower-like of aluminum/carbon nitride

At present, to develop an effective sensor with good photocatalytic activity for triphenylmethane (TPM) dyes in wastewater is urgently needed. Herein, Ag nanoparticles anchored on the flower like of aluminum/carbon nitride (Al/f-CN/Ag) are prepared. Importantly, the optimal Al/f-CN/Ag substrate shows not only a highly selective and sensitive SERS response but also excellent adsorption and photocatalytic performance for TPM molecules, due to the f-CN in Al/f-CN/Ag provides abundant contacting sites for AgNPs, and the highly efficient adsorption activity for TPM molecules through π-π stacking. Also, finite-difference time-domain (FDTD) analysis indicates that more vital “hot spots” are generated by AgNPs which are perfectly anchored in the petal gaps of Al/f-CN, further confirming the superiority of flower-like nanostructure. In addition, the Al/f-CN/Ag displays distinguished SERS activity with a detection limit of ~10−10 mol·L−1 for crystal violet (CV) and ~ 10−8 mol·L−1 for other TPM molecules, and the degradation rate for CV is as high as 99.9% in 140 mins. Moreover, the Raman activity of the substrate is almost unchanged in air within 95 days and after seven cycles. Thus, the constructed versatile SERS substrate will be an attractive nanomaterial for the detection and removal of TPM dyes in wastewater.

Identification and optimization of triphenylmethane dyes removal by Streptomyces sp. from forest soil

This study identified a common Streptomyces sp. (MN262194) from forest soil as an efficient decolorizer of triphenylmethane (TPM) dyes. Partial 16S rRNA sequencing identified the isolate as possibly Streptomyces bacillaris (similarity 99.32%). Live and dead cells of Streptomyces sp. were applied to decolorize Malachite Green (MG), Methyl Violet (MV), Crystal Violet (CV), and Cotton Blue (CB). The decolorization efficacy for both cell types was further optimized based on One-Factor-At-A-Time (OFAT) method to determine the influence of pH, agitation speed (rpm), biomass (g), initial dye concentration (mg L− 1), and oxygen. Removal of TPM dyes was repeated for both live and dead cells using combined optimal conditions determined for each biomass type. Results revealed that optimum conditions for live cells were pH 7, 100 rpm agitation, 0.5 g cell biomass, initial dye concentration of 100 mg L− 1 (50 mg L− 1 for CB), and with the presence of oxygen. In contrast, pH 9 (MG, MV, CV) and pH 3 (CB), with 100 rpm agitation, 0.75 g cell biomass, and initial dye concentrations of 100 mg L− 1 (50 mg L− 1 for CB), were the optimum conditions for dead cells. At optimal conditions, live cells showed significantly higher decolorization activities for all dyes (MG 95%, MV 92%, CV 87%, CB 68%). Removal of TPM dyes was via biosorption and biodegradation, detected with changes of ultraviolet-visible spectra between the untreated dye and treated dye. Sorption by Streptomyces sp. conforms to the Langmuir isotherm model. Streptomyces sp. was established as an effective decolorizer for most TPM dyes with > 85% decolorization (with the exception for CB).

Facile preparation of hierarchical porous 2MgO · B2O3 · 2H2O nanostructure with ultra-high adsorption performance for triphenylmethane dyes removal

The fan-like 2MgO · B2O3 · 2H2O porous nanostructures were prepared by a solvothermal approach. FT-IR, XRD, TG-DTA, SEM, and TEM were used to characterize the obtained sample, which was constructed by nanobelts with 20 nm in width, about 5 nm in thickness and 2 μm in length. Its specific surface area was measured as 118.94 m2/g. It exhibited ultra-high removal of triphenylmethane dyes for AF, MG and BF from aqueous solution, in which the maximum adsorption capacities are much higher than those of most reported adsorbents. The higher absorption for triphenylmethane dyes can be attributed to the positive surface charge, the main existing mesopores and macropores, and larger specific surface area of the prepared 2MgO · B2O3 · 2H2O sample, which make the absorbent and anionic dye molecules existing both the stronger electrostatic attraction and hydrogen bonds of N–H· · · O and O–H· · · N. The adsorption kinetics and isotherm were found to conform to pseudo-second-order model and Langmuir model. The competitive adsorption for BF and MG and the adsorption mechanism were also investigated. The as-prepared sample is of larger adsorption capacity and good reusability, which makes it valuable in potential wastewater treatment application.

Hierarchically porous covalent organic framework for adsorption and removal of triphenylmethane dyes

Triphenylmethane (TPM) dyes as one of common organic pollutants have been severely criticized while it comes to their negative effects on the environment and human beings. In this study, using 1,3,5-triformylbenzene (Tb) and benzidine (Bd) as building blocks, we fabricated a hierarchically porous covalent organic framework foam (TbBd-foam) via a simple yet accomplished gas-foaming technique to adsorb and remove two typical TPM dyes malachite green (MG) and crystal violet (CV) from aqueous solution. Attributed to the use of baking soda, CO2 effervesced continuously during the crystallization of TbBd-foam, and thereby creating disordered porous system which can quicken the diffusion of MG and CV through the pore network in TbBd-foam. Benefit from this merit, the adsorption equilibrium of MG and CV can reach only with 30 min, and the maximum adsorption capacity of TbBd-foam for MG and CV was calculated to be 172.4 mg g−1 and 149.3 mg g−1, respectively. More fascinatingly, TbBd-foam can be facilely recycled upon the treatment with ethanol solution containing HCl (0.1%). Taken together, TbBd-foam might be a potential adsorbent for high-performance contaminated water remediation.

Removal of triphenylmethane dye from aqueous solutions through an adsorption process over waste materials

Water pollution is the most significant issue due to rapid growing industrial development especially textile dye industry. Therefore, the adsorption process experiment was conducted to determine the removal ability of the adsorbent chosen. The removal rate and adsorption capacity of Phenol red and Cresol were analyzed by using eggshell adsorbent in the adsorption process. The experiment was conducted with parameters of initial concentration, dosage, pH and contact time. Results indicated that the removal rate achieved more than 90% and the adsorption capacity exceeded more than 5 mg/g. The functional group before adsorption process eggshell adsorbent and after adsorption process eggshell adsorbent was analyzed by using FTIR (Fourier Transform Infrared Spectroscopy). The study of adsorption isotherm and kinetics model was carried out to identify the efficiency of the eggshell adsorbent reacting with the dye solution. The adsorption isotherm that applied in this research was Langmuir isotherm, Jovanovic isotherm and Freundlich isotherm. Moreover, Pseudo-first-order and Pseudo-second-order chosen were conducted to determine the kinetic studies. In short, eggshell adsorbent is highly effective on dye removal through adsorption capacity. The functional group of the eggshell adsorbent was found such as alcohols, phenol, alkanes, carbonyls, ester, saturated aliphatic, aldehydes, aromatics, 2°amines and phosphorus. For kinetics study, Freundlich isotherm was analyzed as the best fit isotherm model as it achieved the highest R2 value which is closed to 1 and Pseudo-second-order was analyzed as the best fit kinetic model in this experiment. Therefore, eggshell adsorbent is highly effective in dye removal.

Carboxyl-Functionalized Covalent Organic Frameworks for the Adsorption and Removal of Triphenylmethane Dyes

The introduction of a functional moiety into a covalent organic framework (COF) is of great significance in promoting its wide applications. Here we show the one-pot synthesis of carboxyl-functionalized COF-TzDBd via the direct condensation of 1,3,5-tris(4-formyl-phenyl) triazine (Tz) and 4,4′-diamino-[1,1′-biphenyl]-2,2′-dicarboxylic acid (DBd). The prepared TzDBd showed good crystallinity, mesoporous pores, and high chemical stability. It was applied for ultrafast adsorption and the efficient elimination of triphenylmethane dyes. The adsorption isotherms, adsorption thermodynamics, kinetics, and reusability of the prepared carboxyl-COF were investigated in detail. The adsorption of crystal violet (CV) and brilliant green (BG) on TzDBd followed the pseudo-second-order adsorption kinetic model and reached equilibrium within 2 min at the initial concentration of 100 mg L–1. The adsorption of triphenylmethane dyes on TzDBd fit well with the Langmuir adsorption model and gave the maximum adsorption capacities of 307.7 and 276.1 mg g–1 for CV and BG, respectively. The predesigned mesoporous pores, conjugated phenyl structure, and negatively charged carboxyl groups on TzDBd significantly facilitate the adsorption kinetics for large cationic triphenylmethane dyes. The ultrafast kinetics, high adsorption capacity, and good reusability endow the carboxyl-functionalized COF with great potential for removing triphenylmethane dyes from an aqueous environment.

Removal of triphenylmethane dyes in single-dye and dye-metal mixtures by live and dead cells of metal-tolerant Penicillium simplicissimum

ABSTRACT In the absence of various metal ions, live cells of Penicillium simplicissimum decolorized Crystal Violet (CV), Methyl Violet (MV), Malachite Green (MG) and Cotton Blue (CB) (75.6–90.8%, 0.5–2 h) more efficiently than dead cells (43.9–75.2%, 4 h). Cu(II) enhanced CB removal by live and dead cells (64.1–82.0%) but with Cd(II), Zn(II) and Cr(III), removal of CV, MV and MG were inhibited. Pb(II) inhibited dye removal by live cells (63.1–78.1%), while dead cells remained unaffected (40.6–74.0%). Dye removal was attributed to binding to hydroxyl, carbonyl, amino, phosphoryl and nitro groups based on FTIR analyses. Dye-metal-fungi interactions revealed new binding sites and non-involvement of specific functional groups that previously interacted with single dyes. Hence, this study indicated that isolate 10 (especially live cells) is capable of removing dyes from dye-metal solutions.

Equilibrium, kinetic and thermodynamic studies of the removal of triphenyl methane dyes from wastewater using iodopolyurethane powder

The removal and recovery of rosaniline and brilliant green were studied using batch and dynamic processes. The maximum sorption of these dyes (∼100%) was obtained in a pH range of 6–10 with a shaking time of 2–5min. The sorption kinetics were best described by the pseudo-second-order model (R2=0.993). The variation in the sorption of rosaniline and brilliant green with temperature results in average values of ΔH and ΔG (i.e., −65.7kJmol−1 and −8.1kJmol−1, respectively). The sorption capacity of iodo-polyurethane powder (Iodo-PUP) was 106.8 and 154.4mgg−1 for rosaniline and brilliant green, respectively. The dye removal percentage and detection limit were 99.5% and 20ngmL−1, respectively. The isotherms exhibit good correlation (R2=0.9985) with a zero intercept (0.0045). Successful application was achieved for environmental samples (i.e., industrial, laundry and sewage wastewater). The average recovery and RSD were 85.2% and 4.9%, respectively.

Adsorption and removal of triphenylmethane dyes from water by magnetic reduced graphene oxide.

Triphenylmethane (TPM) dye is one of the most prevalent and recalcitrant water contaminants. Magnetic reduced graphene oxide (rGO) is an efficient adsorbent for organic pollutants removal. However, the performance and adsorption kinetics of magnetic rGO towards TPM have not yet been studied. In this study, a magnetic Fe3O4@rGO nano-composite, which could be easily removed from water with a simple magnetic separation step was synthesized and characterized. The magnetic rGO showed fast adsorption rate and high adsorption capacity towards different TPM dyes (the Langmuir monolayer adsorption capacity is 64.93 mg/g for adsorption of crystal violet). The adsorption processes are well-fitted to the pseudo-second-order kinetic model (R(2) > 0.99) and the Langmuir isotherm model (R(2) = 0.9996). Moreover, the magnetic rGO also showed excellent recycling and regeneration capabilities. The results indicated that adsorption with magnetic rGO would be a promising strategy to clean up the TPM contamination.

Removal of Triphenylmethane Dyes by Bacterial Consortium

A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes.

Removal of Triphenylmethane Dye from Aqueous Solution by Carbonaceous Adsorbent

Abstract Removal of acid blue 1 from aqueous solution on activated carbon produced from Salvadora oleoides was investigated. The samples were characterized by BET surface area, BJH pore volume and pore diameter, XRD, SEM, EDS and FTIR analysis. The surfaces contain functional groups like ketones and hydroxyl which disappeared at high activation temperature; relatively high amount of carbon w.r.t. oxygen was found with the increase in activation temperature; the increase in surface area and development of porous structures showed a positive effect on the adsorption capacity. Adsorption of the dye on carbon at 10 and 45°C showed that the first order, Bangham and Elovich and parabolic diffusion equations apply to the kinetic data. The adsorption rate increased with the temperature and with thermal activation of the sample. Thermodynamic parameters like ΔE≠, ΔH≠, ΔS≠ and ΔG≠ were calculated from the kinetic data. The negative values of ΔS≠ reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (ΔG≠), which represents the driving force for the affinity of dye for the carbon, increased with the increase in activation temperature.