Rapid Dye Removal Research Articles

One water-stable magnetic coordination polymer material (Fe3O4@PmPD–[Co-BT]) as an efficient adsorbent for rapid dye removal

Benefiting from the framework, Fe3O4@PmPD–[Co-BT] has an excellent effect of removing CR from wastewater, and the adsorption capacity was 347.8 mg g−1.

Enhancement of laccase production in a new isolated Trametes hirsuta LBF-AA017 by lignocellulosic materials and its application for removal of chemical dyes

Laccase is one of the extracellular ligninolytic enzymes highly produced by white rot fungi (WRF) and widely used in industrial processes such as decolorizing of synthetic dyes. In this study, the enzyme was produced by a new isolated WRF (Trametes hirsuta LBF-AA017) through two types of fermentation: submerged and solid state fermentation. In the submerged culture, several local lignocellulosic materials (0.5% w/v): bagasse, palm kernel cake (PKC), sugar palm fruit cake (SPFC), corn cobs (CC), tobacco road (TR), were used as laccase inducers. Among 5 materials tested, treatment using SPFC resulted highest laccase production, 645 U L−1 in the 9th day. Higher concentration of SPFC (5% w/v) enhanced laccase poduction by the fungus up to 2034.354 U L−1 in 9 days. Addition of SPFC above 25% (w/v) into culture medium made solid state condition and significantly enhance the production of laccase by the fungus. The crude laccase could effectively decolorize three types of chemical dyes: congo red (CR), brilliant blue G (BBG), coomassie brilliant blue (CBB), in a short period. The laccase could effectively remove three kind of tested dyes with various rates: 45, 91, 48%, respectively for CR, BBG and CBB in one hour reaction. Rapid removal of dyes, especially for BBG, by the laccase T. hirsuta LBF-AA017 has initially proven the potential to be applied for environmental biotechnology.

Rapid Discoloration of Methyl Orange in Water by Conductive Cu/Cu2O/rGO Modified Polyester Fabric

A new rapid dye removal method is introduced by using a conductive polyester fabric prepared through in-situ synthesis of Cu/Cu2O/rGO nanocomposites. Cu2O and Cu nanoparticles were deposited on the polyester fabric with triangular, spherical and rod-like shapes due to introducing GO nanosheets and EDTA into the synthesis media. The cauliflower-like Cu/Cu2O/rGO nanocomposites coated polyester fabric exhibited remarkable removal of methyl orange (MO) in a short time (more than 92% within 30 min). This can be attributed to the shape, presence of GO or EDTA that was subsequently created nanoparticles with smaller size, higher electrical conductivity and more specific surface area for removal of MO.

Cu(BDC) as a catalyst for rapid reduction of methyl orange: room temperature synthesis using recycled terephthalic acid

Terephthalic acid was recycled from waste PET bottles with a basic hydrolysis technique and characterized with UV and FTIR spectroscopy. Copper-based metal–organic framework Cu(BDC) was synthesized at room temperature without any additive; two different temperatures were chosen to activate the obtained material. Characterization studies were performed using XRD, N2 physisorption, STEM and EDX. The obtained material was tested as a catalyst for the reduction of methyl orange with NaBH4 in aqueous solutions. Thermal activation at 160 °C proved to be mandatory for catalytic activity; although higher temperature activation did not cause significant enhancement. Rapid dye removal was monitored by continuous photometry at λ max. The results were quite satisfactory (about 85% removal in 5 min); even higher than the published results for precious metal (i.e., Au, Pt and Ag) nanoparticles. In an increased reaction scale, UV–visible spectra and mass spectrum were recorded to help elucidating the possible reaction mechanism. In addition, recycling experiment were performed in 100-ml scale without any kind of re-activation (washing or drying) to show the ability of Cu(BDC) as a stable catalyst for reductive dye removal (and probably similar reactions as well).

Interfacially crosslinked composite porous membranes for ultrafast removal of anionic dyes from water through permeating adsorption

The dye wastewater is one of the most difficult industrial wastewaters to treat. It keeps a big challenge to realize fast removal of dyes from water by membrane filtration due to the trade-off between separation selectivity and permeation flux for ultrafiltration or nanofiltration (NF) process. Here we report novel composite porous membranes which can remove anionic dyes from water by ultrafast permeating adsorption. A crosslinked polyethyleneimine (PEI) polymer with strong adsorption ability was incorporated onto a nylon microfiltration membrane by the interfacial amidation reaction between PEI and trimesoyl chloride. The obtained composite membranes were used for the decolorization of dye solution by permeation mode. It was shown that the composite membranes were able to nearly completely remove anionic dyes in acidic conditions with high permeation fluxes. In an optimized case, the adsorption capacity of Sunset Yellow for the composite membranes reached 0.7mg/cm2 with a high flux of 85L/m2h under a ultralow pressure of 0.01bar. This flux was far much higher than that of NF membranes, about 10L/m2hbar. The pH-dependent electrostatic interaction between PEI and anionic dyes was responsible for the rapid dye removal. The adsorption saturated membranes could be effectively regenerated by a simple alkaline washing.

Simultaneous and rapid dye removal in the presence of ultrasound waves and a nano structured material: experimental design methodology, equilibrium and kinetics

Tin sulfide nanoparticles loaded on activated carbon (SnS-AC) were prepared and characterized by FE-SEM, XRD, FT-IR and EDX.

Strong enhancement of dye removal through addition of sulfite to persulfate activated by a supported ferric citrate catalyst

In this study, reductive sulfite (S(IV)) was innovatively introduced into activated carbon fibers supported ferric citrate (Cit-Fe@ACFs) and persulfate (PS) process for organic dye removal. The addition of S(IV) enhanced the catalytic elimination rate of organic dye Reactive Red M-3BE from 15.2% to 96.2% in 12min (kobs (pseudo-first-order rate constant) from 0.015 to 0.324min−1). More importantly, the simultaneous removal of S(IV), which is a common inorganic pollutant, was also achieved. This Cit-Fe@ACFs/S(IV)/PS system exhibited superior sustained catalytic ability and distinguished pH-tolerant performance for the simultaneous rapid removal of dyes and inorganic S(IV). Furthermore, the reaction rate constant (kobs) increased with the increase of concentration of S(IV) below 1mM, while decreased over 1mM. Finally, various radical scavengers were used together with electron paramagnetic resonance spectroscopy to confirm that hydroxyl (OH), sulfate (SO4−) and peroxymonosulfate (SO5−) radicals served as the major reactive oxygen species in the Cit-Fe@ACFs/S(IV)/PS system. This study provides a promising idea to use polluting S(IV) in sewage treatment for the simultaneous removal of organic and inorganic pollutants.

Modeling of competitive ultrasonic assisted removal of the dyes – Methylene blue and Safranin-O using Fe3O4 nanoparticles

The study was focused on the simultaneous removal of Methylene blue (MB) and Safranin-O (SO), as most together hazardous dye in wastewater, from aqueous solution by ultra-sonic-assisted adsorption onto the developed adsorbent i.e. Fe3O4 NPs. Fe3O4 NPs were synthesized, by using central composite design (CCD), the effects of variables such as pH, adsorbent dosage, MB concentration, SO concentration and contact time on binary dyes removal were examined and optimized values were found to be 6, 0.01g, 10 and 20mg/L and 2min, respectively. The very rapid removal of dyes makes this novel adsorbent as a promising tool for wastewater management applications. Different adsorption isotherm model i.e. Langmuir, Freundlich, non-modified Langmuir, modified competitive Langmuir, modified extended Langmuir, extended Freundlich and sips models are studied out of which extended-Freundlich model proved to be the best fit to equilibrium data because of correlation value (R2) is 0.99 which is very close to 1, additionally it depicts the high adsorption capacity around (89.2–91.9mgg−1). An empirical extension of competitive extended-Freundlich model was proposed to predict the simultaneous adsorption behavior of MB and SO. It was observed that pseudo-second-order equation is suitable to fit the experimental data.

Plant waste materials from restaurants as the adsorbents for dyes

This paper has demonstrated the valorization of inexpensive and readily available restaurant waste containing most consumed food and beverage residues as adsorbents for methylene blue dye. Coffee, tea, lettuce and citrus waste have been utilized without any pre-treatment, thus the adsorption capacities and dye removal efficiency were determined. Coffee waste showed highest adsorbent capacity, followed by tea, lettuce and citrus waste. The dye removal was more effective as dye concentration increases from 5 up to 60 mg/L. The favorable results obtained for lettuce waste have been especially encouraged, as this material has not been commonly employed for sorption purposes. Equilibrium data fitted very well in a Freundlich isotherm model, whereas pseudo-second-order kinetic model describes the process behavior. Restaurant waste performed rapid dye removal at no cost, so it can be adopted and widely used in industries for contaminated water treatment.

Rapid Removal of Dyes by Carbonized Sludge: Process, Effects of Environmental Factors, and Mechanism

The disposal of sewage sludge is one of the most pressing environmental issues with increasing amount of sewage sludge. Among these methods, carbonized sludge is thought to be a potential approach for resource utilization and becomes one of the most widely used adsorbent for wastewater treatment. However, effects of environmental factors and its relative mechanism for pollutant removal have not been thoroughly studied. In this study, carbonized sludge derived from sewage sludge was investigated. The adsorption of C. I. Acid Red 73 (AR 73) on the carbonized sludge was a rapid process and fit well to the Langmuir model with a maximum adsorption capacity of 137.95 mg g−1 at pH 6.8. In addition, the common coexisting ions had a negligible negative impact on dye adsorption on the carbonized sludge. The magnetic carbonized sludge also exhibited high adsorption efficiency for other anionic dyes. Furthermore, the adsorption mechanism was proposed by analysis Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), high surface area, and proper porous structure as well as the π-π interaction between dye molecules and the graphene carbon surface were likely be the mechanisms of dye adsorption. Overall, the results reported herein indicated that carbonized sludge is very attractive and implies a potential of practical application for dyeing effluent treatment.

Rapid adsorption of binary dye pollutants onto the nanostructred mesoporous alumina

In this study ordered mesoporous alumina (OMA) with pore size of about 5nm has been used for removal of dye pollutants from binary systems including methyl orange+bromothymol blue, methyl orange+reactive yellow and methyl orange+methyl violet. Derivative spectrophotometry was used for simultaneous determination of the dyes concentrations. The results show that OMA is a good adsorbent for rapid removal of dyes (especially anionic ones) from aqueous solution. Characterization of OMA has been performed by TEM and XRD techniques. The adsorption kinetic data of binary dye mixtures follows the competitive statistical rate theory (SRT) model well.

Rapid removal of dyes under visible irradiation over activated carbon fibers supported Fe(III)–citrate at neutral pH

Activated carbon fibers supported ferric citrate (FeCit@ACFs) as a heterogeneous catalyst for the rapid removal of dyes under visible light irradiation is reported. The FeCit@ACFs/H2O2 system exhibited remarkable catalytic activity across a wide pH range (2–10). Moreover, the catalyst presented excellent sustained catalytic ability in these experiments. The effects of catalyst dosage, and H2O2 concentration were also evaluated. Electron paramagnetic resonance (EPR) spectroscopy confirmed the hydroxyl radicals (OH) involved as the active species in the catalytic system. Moreover, the superoxide radical (O2-) was not detected by EPR, suggesting better use of H2O2 for removal of dyes. According to the observed effects of the scavengers n-butanol and KI, hydroxyl radicals, especially the surface-bounded OH, had a dominant role in the oxidation of dyes. More importantly, the high adsorption capacity of ACFs could efficiently enhance the removal rate of dyes by the surface-bounded OH. This paper discusses a possible catalytic oxidation mechanism in the FeCit@ACFs/H2O2 system, which provides a feasible approach for the elimination of widely existing pollutants.

Enhanced decomposition of dyes by hemin-ACF with significant improvement in pH tolerance and stability

In this study, we evaluated a novel heterogeneous catalytic system (hemin-ACF/H2O2) based on activated carbon fiber supported hemin for the rapid removal of dyes. Contrast experiments, effects of pH and temperature, and sustained catalytic stability of hemin-ACF for the catalytic decomposition of azo dye RR195 used as a model pollutant were investigated. Surprisingly, the introduction of ACF significantly enhanced the decomposition of dyes by hemin with an obvious improvement in pH tolerance and stability. Inhibition and probe studies combined with electron paramagnetic resonance (EPR) were conducted to ascertain the role of several radicals (OH, O2−/HO2, 1O2 and FeIVO) on dye degradation. ACF are rich in free electrons, and the π-conjugated macrocyclic structure of hemin may present convenient channels for the transfer of free electrons from the ACF, promoting the generation of hydroxyl radicals and high-valence iron species. These results are promising because they offer new insight for the application of hemin as a catalyzer upon treatment of organic pollutants and contribute to identification of the interaction between support material and catalyzer from a new perspective.

SULFOBROMOPHTHALEIN SODIUM EXCRETION TEST AS A MEASURE OF LIVER FUNCTION IN PREMATURE INFANTS

In normal adults, following a single intravenous injection of BSP, the logarithmic decline of plasma BSP levels is rectilinear. In patients with hepatic disease, the plotted values are curvilinear with flattening of the curve, or "saturation," occurring at high plasma BSP concentration. The use of the excretion curve provides a dynamic representation of the hepatic uptake of dye throughout the test, avoids the theoretic objections to the 45 minute test, and obviates the necessity for plasma volume determinations. Thirty-five healthy prematures of varying age and weight were the subjects of a study of liver function by the bromsulphalein excretion test. As measured by the BSP excretion test, there is progressive maturation of liver function with age in prematures which does not necessarily correlate with weight. The excretion curves obtained in prematures 18 to 28 hours of age resemble those of older patients with severely impaired hepatic function. Clearance of dye in these subjects is slow throughout the test. With increasing age there is a gradual change in the pattern of the curves characterized by the appearance of the initial sharp slopes coincident with rapid dye removal. "Saturation," or flattening of the curves, persists until a later age and takes place at progressively lower plasma levels. This biphasic pattern is apparent in the prematures over 4 days of age. The normal adult pattern is not attained until about 6 to 8 weeks although the 45 minute retention values become normal at three weeks. The gradual development of normal excretion curves in premature infants may be explained by the progressive maturation of the anatomic and physiologic factors involved in the mechanism of BSP clearance. The increasing size of the capillary network in the liver that occurs with advancing age in effect increases hepatic blood flow and exposes a greater volume of blood in the sinusoids to the activity of the liver. The appearance of the initial sharp slopes, representing rapid dye removal, probably results from this increasing vascularity and possibly from maturation of the hepatic uptake mechanism. The continuance of the biphasic character of the curves probably results from inability to excrete the dye efficiently into bile.