Displaying publications 1 - 20 of 104 in total

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  1. Abdullah AH, Abdullah EA, Zainal Z, Hussein MZ, Ban TK
    Water Sci Technol, 2012;65(9):1632-8.
    PMID: 22508126 DOI: 10.2166/wst.2012.057
    The adsorption of methyl orange dye from aqueous solution onto penta-bismuth hepta-oxide nitrate, Bi(5)O(7)NO(3), synthesized by precipitation method, was studied in a batch adsorption system. The effects of operation parameters such as adsorbent dose, initial dye concentration, pH and temperature were investigated. The adsorption equilibrium and mechanism of adsorption was evaluated by Langmuir and Freundlich isotherm and different kinetic models, respectively. The results indicate that adsorption is highly dependent on all operation parameters. At optimum conditions, the adsorption capacity was found to be 18.9 mg/g. The adsorption data fits well with the Langmuir isotherm model indicating monolayer coverage of adsorbate molecules on the surface of Bi(5)O(7)NO(3). The kinetic studies show that the adsorption process is a second-order kinetic reaction. Although intra-particle diffusion limits the rate of adsorption, the multi-linearity plot of intra-particle model shows the importance of both film and intra-particle diffusion as the rate-limiting steps of the dye removal. Thermodynamic parameters show that the adsorption process is endothermic, spontaneous and favourable at high temperature.
    Matched MeSH terms: Coloring Agents/chemistry*
  2. Abdullah AZ, Ling PY
    J Hazard Mater, 2010 Jan 15;173(1-3):159-67.
    PMID: 19740600 DOI: 10.1016/j.jhazmat.2009.08.060
    The ambient sonocatalytic degradation of congo red, methyl orange, and methylene blue by titanium dioxide (TiO(2)) catalyst at initial concentrations between 10 and 50mg/L, catalyst loadings between 1.0 and 3.0mg/L and hydrogen peroxide (H(2)O(2)) concentrations up to 600 mg/L is reported. A 20 kHz ultrasonic processor at 50 W was used to accelerate the reaction. The catalysts were exposed to heat treatments between 400 and 1000 degrees C for up to 4h to induce phase change. Sonocatalysts with small amount of rutile phase showed better sonocatalytic activity but excessive rutile phase should be avoided. TiO(2) heated to 800 degrees C for 2h showed the highest sonocatalytic activity and the degradation of dyes was influenced by their chemical structures, chemical phases and characteristics of the catalysts. Congo red exhibited the highest degradation rate, attributed to multiple labile azo bonds to cause highest reactivity with the free radicals generated. An initial concentration of 10mg/L, 1.5 g/L of catalyst loading and 450 ppm of H(2)O(2) gave the best congo red removal efficiency of above 80% in 180 min. Rate coefficients for the sonocatalytic process was successfully established and the reused catalyst showed an activity drop by merely 10%.
    Matched MeSH terms: Coloring Agents/chemistry*
  3. Abdullah EA, Abdullah AH, Zainal Z, Hussein MZ, Ban TK
    J Environ Sci (China), 2012;24(10):1876-84.
    PMID: 23520859
    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents. The synthesized product was characterized by different analytical techniques. The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants. Different kinetic, isotherm and diffusion models were chosen to describe the adsorption process. X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however, the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes. Dyes removal was found to be a function of adsorbent dosage, initial dye concentration, solution pH and temperature. The reduction of Langmuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent. Mass transfer can be described by intra-particle diffusion at a certain stage, but it was not the rate limiting step that controlled the adsorption process. Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.
    Matched MeSH terms: Coloring Agents/chemistry*
  4. Abdullah J, Ahmad M, Heng LY, Karuppiah N, Sidek H
    Anal Bioanal Chem, 2006 Nov;386(5):1285-92.
    PMID: 17031625
    The stacked-film immobilization of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in hybrid nafion/sol-gel silicate film and horseradish peroxidase (HRP) in chitosan, performed in order to allow the determination of phenolic compounds, was investigated via an optical method. The stacked films were deposited onto a microscope glass slide by a spin-coating technique. The quinone or free radical product formed by the enzymatic reactions of phenolic compounds interacts with MBTH to form azo-dye products, which can be measured spectrophotometrically at a wavelength of 500 nm. The color intensity of the product was found to increase in proportion to the phenolic concentration after 5 min of exposure. The response of the biosensor was linear over concentration ranges of 0.025-0.500, 0.010-0.070 and 0.050-0.300 mM for guaiacol, resorcinol and o-cresol, respectively, and gave detection limits of 0.010, 0.005 and 0.012 mM. The sensor exhibited good sensitivity and stability for at least two months.
    Matched MeSH terms: Coloring Agents/chemistry
  5. Abilaji S, Narenkumar J, Das B, S S, Rajakrishnan R, Sathishkumar K, et al.
    Chemosphere, 2023 Dec;345:140516.
    PMID: 37879370 DOI: 10.1016/j.chemosphere.2023.140516
    Azo dyes are the most varied class of synthetic chemicals with non-degradable characteristics. They are complex compounds made up of many different parts. It was primarily utilized for various application procedures in the dyeing industry. Therefore, it's crucial to develop an economical and environmentally friendly approach to treating azo dyes. Our present investigation is an integrated approach to the electrooxidation (EO) process of azo dyes using RuO2-IrO2-TiO2 (anode) and titanium mesh (cathode) electrodes, followed by the biodegradation process (BD) of the treated EO dyes. Chemical oxygen demand (COD) removal efficiency as follows MB (55%) ≥ MR (45%) ≥ TB (38%) ≥ CR (37%) correspondingly. The fragment generated during the degradation process which was identified with high-resolution mass spectrometry (HRMS) and its degradation mechanism pathway was proposed as demethylation reaction and N-N and C-N/C-S cleavage reaction occurs during EO. In biodegradation studies by Aeromonas hydrophila AR1, the EO treated dyes were completely mineralized aerobically which was evident by the COD removal efficiency as MB (98%) ≥ MR (92.9%) ≥ TB (88%) ≥ CR (87%) respectively. The EO process of dyes produced intermediate components with lower molecular weights, which was effectively utilized by the Aeromonas hydrophila AR1 and resulted in higher degradation efficiency 98%. We reported the significance of the enhanced approach of electrochemical oxidation with biodegradation studies in the effective removal of the pollutants in dye industrial effluent contaminated water environment.
    Matched MeSH terms: Coloring Agents/chemistry
  6. Adeyi AA, Jamil SNAM, Abdullah LC, Choong TSY, Lau KL, Alias NH
    Molecules, 2020 Jun 07;25(11).
    PMID: 32517324 DOI: 10.3390/molecules25112650
    Proper remediation of aquatic environments contaminated by toxic organic dyes has become a research focus globally for environmental and chemical engineers. This study evaluates the adsorption potential of a polymer-based adsorbent, thiourea-modified poly(acrylonitrile-co-acrylic acid) (T-PAA) adsorbent, for the simultaneous uptake of malachite green (MG) and methylene blue (MB) dye ions from binary system in a continuous flow adsorption column. The influence of inlet dye concentrations, pH, flow rate, and adsorbent bed depth on adsorption process were investigated, and the breakthrough curves obtained experimentally. Results revealed that the sorption capacity of the T-PAA for MG and MB increase at high pH, concentration and bed-depth. Thomas, Bohart-Adams, and Yoon-Nelson models constants were calculated to describe MG and MB adsorption. It was found that the three dynamic models perfectly simulate the adsorption rate and behavior of cationic dyes entrapment. Finally, T-PAA adsorbent demonstrated good cyclic stability. It can be regenerated seven times (or cycles) with no significant loss in adsorption potential. Overall, the excellent sorption capacity and multiple usage make T-PAA polymer an attractive adsorbent materials for treatment of multicomponent dye bearing effluent in a fixed-bed column system.
    Matched MeSH terms: Coloring Agents/chemistry
  7. Agha HM, Abdulhameed AS, Jawad AH, Aazmi S, Sidik NJ, De Luna Y, et al.
    Int J Biol Macromol, 2024 Feb;258(Pt 1):128792.
    PMID: 38110162 DOI: 10.1016/j.ijbiomac.2023.128792
    Herein, a natural material including chitosan (CTS) and algae (food-grade algae, FGA) was exploited to attain a bio-adsorbent (CTS/FGA) for enhanced methyl violet 2B dye removal. A study of the FGA loading into CTS matrix showed that the best mixing ratio between CTS and FGA to be used for the MV 2B removal was 50 %:50 % (CTS/FGA; 50:50 w/w). The present study employed the Box-Behnken design (RSM-BBD) to investigate the impact of three processing factors, namely CTS/FGA-(50:50) dose (0.02-0.1 g/100 mL), pH of solution (4-10), and contact time (5-15 min) on the decolorization rate of MV 2B dye. The results obtained from the equilibrium and kinetic experiments indicate that the adsorption of MV 2B dye on CTS/FGA-(50:50) follows the Langmuir and pseudo-second-order models, respectively. The CTS/FGA exhibits an adsorption capacity of 179.8 mg/g. The characterization of CTS/FGA-(50:50) involves the proposed mechanism of MV 2B adsorption, which primarily encompasses various interactions such as electrostatic forces, n-π stacking, and H-bonding. The present study demonstrates that CTS/FGA-(50:50) synthesized material exhibits a distinctive structure and excellent adsorption properties, thereby providing a viable option for the elimination of toxic cationic dyes from polluted water.
    Matched MeSH terms: Coloring Agents/chemistry
  8. Agha HM, Abdulhameed AS, Jawad AH, Sidik NJ, Aazmi S, Wilson LD, et al.
    Int J Phytoremediation, 2024;26(4):459-471.
    PMID: 37583281 DOI: 10.1080/15226514.2023.2246596
    This work aims to apply the use of food-grade algae (FGA) composited with chitosan-benzaldehyde Schiff base biopolymer (CHA-BD) as a new adsorbent (CHA-BA/FGA) for methyl violet 2B (MV 2B) dye removal from aqueous solutions. The effect of three processing variables, including CHA-BA/FGA dosage (0.02-0.1 g/100 mL), pH solution (4-10), and contact duration (10-120 min) on the removal of MV 2B was investigated using the Box-Behnken design (BBD) model. Kinetic and equilibrium dye adsorption profiles reveal that the uptake of MV 2B dye by CHA-BA/FGA is described by the pseudo-second kinetics and the Langmuir models. The thermodynamics of the adsorption process (ΔG°, ΔH°, and ΔS°) reveal spontaneous and favorable adsorption parameters of MV 2B dye onto the CHA-BA/FGA biocomposite at ambient conditions. The CHA-BA/FGA exhibited the maximum ability to absorb MV 2B of 126.51 mg/g (operating conditions: CHA-BA/FGA dose = 0.09 g/100 mL, solution pH = 8.68, and temperature = 25 °C). Various interactions, including H-bonding, electrostatic forces, π-π stacking, and n-π stacking provide an account of the hypothesized mechanism of MV 2B adsorption onto the surface of CHA-BA/FGA. This research reveals that CHA-BA/FGA with its unique biocomposite structure and favorable adsorption properties can be used to remove harmful cationic dyes from wastewater.
    Matched MeSH terms: Coloring Agents/chemistry
  9. Ahmad AA, Hameed BH
    J Hazard Mater, 2010 Mar 15;175(1-3):298-303.
    PMID: 19883979 DOI: 10.1016/j.jhazmat.2009.10.003
    In this work, the adsorption potential of bamboo waste based granular activated carbon (BGAC) to remove C.I. Reactive Black (RB5) from aqueous solution was investigated using fixed-bed adsorption column. The effects of inlet RB5 concentration (50-200mg/L), feed flow rate (10-30 mL/min) and activated carbon bed height (40-80 mm) on the breakthrough characteristics of the adsorption system were determined. The highest bed capacity of 39.02 mg/g was obtained using 100mg/L inlet dye concentration, 80 mm bed height and 10 mL/min flow rate. The adsorption data were fitted to three well-established fixed-bed adsorption models namely, Adam's-Bohart, Thomas and Yoon-Nelson models. The results fitted well to the Thomas and Yoon-Nelson models with coefficients of correlation R(2)>or=0.93 at different conditions. The BGAC was shown to be suitable adsorbent for adsorption of RB5 using fixed-bed adsorption column.
    Matched MeSH terms: Coloring Agents/chemistry*
  10. Ahmad M, Asghar A, Abdul Raman AA, Wan Daud WM
    PLoS One, 2015;10(10):e0141348.
    PMID: 26517827 DOI: 10.1371/journal.pone.0141348
    Fenton oxidation, an advanced oxidation process, is an efficient method for the treatment of recalcitrant wastewaters. Unfortunately, it utilizes H2O2 and iron-based homogeneous catalysts, which lead to the formation of high volumes of sludge and secondary pollutants. To overcome these problems, an alternate option is the usage of heterogeneous catalyst. In this study, a heterogeneous catalyst was developed to provide an alternative solution for homogeneous Fenton oxidation. Iron Zeolite Socony Mobile-5 (Fe-ZSM-5) was synthesized using a new two-step process. Next, the catalyst was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis and tested against a model wastewater containing the azo dye Acid Blue 113. Results showed that the loading of iron particles reduced the surface area of the catalyst from 293.59 to 243.93 m2/g; meanwhile, the average particle size of the loaded material was 12.29 nm. Furthermore, efficiency of the developed catalyst was evaluated by performing heterogeneous Fenton oxidation. Taguchi method was coupled with principal component analysis in order to assess and optimize mineralization efficiency. Experimental results showed that under optimized conditions, over 99.7% degradation and 77% mineralization was obtained, with a 90% reduction in the consumption of the developed catalyst. Furthermore, the developed catalyst was stable and reusable, with less than 2% leaching observed under optimized conditions. Thus, the present study proved that newly developed catalyst has enhanced the oxidation process and reduced the chemicals consumption.
    Matched MeSH terms: Coloring Agents/chemistry*
  11. Ahmad NA, Yook Heng L, Salam F, Mat Zaid MH, Abu Hanifah S
    Sensors (Basel), 2019 Nov 05;19(21).
    PMID: 31694284 DOI: 10.3390/s19214813
    A developed colorimetric pH sensor film based on edible materials for real-time monitoring of food freshness is described. The mixed natural dyes from edible plants Clitoria sp and Brassica sp were extracted and incorporated into ι-carrageenan film as a colorimetric pH sensor film for monitoring food spoilage and its freshness. The color changes of the developed colorimetric sensor film were measured with chromametry and UV-vis spectroscopy, respectively. Experimental results show that colorimetric pH sensor film demonstrated statistically significant differences (p < 0.05) between CIE-L*a*b* coordinates color system indicated that the developed colorimetric sensor film was able to give a gradual change in color over a wide pH range. The color of the colorimetric sensor film also changes discretely and linearly with factors that contribute to food spoilage using shrimp and durian samples. Moreover, the developed colorimetric pH sensor film has the potential to be used as a safe, non-destructive testing and also a flexibly visual method for direct assessment of food freshness indicator during storage.
    Matched MeSH terms: Coloring Agents/chemistry
  12. Ahmad T, Danish M, Rafatullah M, Ghazali A, Sulaiman O, Hashim R, et al.
    Environ Sci Pollut Res Int, 2012 Jun;19(5):1464-84.
    PMID: 22207239 DOI: 10.1007/s11356-011-0709-8
    BACKGROUND: In tropical countries, the palm tree is one of the most abundant and important trees. Date palm is a principal fruit grown in many regions of the world. It is abundant, locally available and effective material that could be used as an adsorbent for the removal of different pollutants from aqueous solution.

    REVIEW: This article presents a review on the role of date palm as adsorbents in the removal of unwanted materials such as acid and basic dyes, heavy metals, and phenolic compounds. Many studies on adsorption properties of various low cost adsorbent, such as agricultural waste and activated carbons based on agricultural waste have been reported in recent years.

    CONCLUSION: Studies have shown that date palm-based adsorbents are the most promising adsorbents for removing unwanted materials. No previous review is available where researchers can get an overview of the adsorption capacities of date palm-based adsorbent used for the adsorption of different pollutants. This review provides the recent literature demonstrating the usefulness of date palm biomass-based adsorbents in the adsorption of various pollutants.

    Matched MeSH terms: Coloring Agents/chemistry
  13. Akpan UG, Hameed BH
    J Hazard Mater, 2009 Oct 30;170(2-3):520-9.
    PMID: 19505759 DOI: 10.1016/j.jhazmat.2009.05.039
    This paper presents the review of the effects of operating parameters on the photocatalytic degradation of textile dyes using TiO2-based photocatalysts. It further examines various methods used in the preparations of the considered photocatalysts. The findings revealed that various parameters, such as the initial pH of the solution to be degraded, oxidizing agents, temperature at which the catalysts must be calcined, dopant(s) content and catalyst loading exert their individual influence on the photocatalytic degradation of any dye in wastewaters. It was also found out that sol-gel method is widely used in the production of TiO2-based photocatalysts because of the advantage derived from its ability to synthesize nanosized crystallized powder of the photocatalysts of high purity at relatively low temperature.
    Matched MeSH terms: Coloring Agents/chemistry*
  14. Al-Alwani MAM, Ludin NA, Mohamad AB, Kadhum AAH, Sopian K
    PMID: 28213142 DOI: 10.1016/j.saa.2017.02.026
    Current study employs mixture of chlorophyll-anthocyanin dye extracted from leaves of Cordyline fruticosa as new sensitizers for dye-sensitized solar cell (DSSCs), as well as betalains dye obtained from fruit of Hylocereus polyrhizus. Among ten pigments solvents, the ethanol and methanol extracts revealed higher absorption spectra of pigments extracted from C. fruticosa and H. polyrhizus respectively. A major effect of temperature increase was studied to increase the extraction yield. The results indicated that extraction temperature between 70 and 80°C exhibited a high dye concentration of each plant than other temperatures. The optimal temperature was around 80°C and there was a sharp decrease of dye concentration at temperatures higher than this temperature. According to experimental results, the conversion efficiency of DSSC fabricated by mixture of chlorophyll and anthocyanin dyes from C. fruticosa leaves is 0.5% with short-circuit current (Isc) of 1.3mA/cm-2, open-circuit voltage (Voc) of 0.62V and fill factor (FF) of 60.16%. The higher photoelectric conversion efficiency of the DSSC prepared from the extract of H. polyrhizus was 0.16%, with Voc of 0.5V, Isc of 0.4mA/cm-2 and FF of 79.16%. The DSSC based betalain dye extracted from fruit of H. polyrhizus shows higher maximum IPCE of 44% than that of the DSSCs sensitized with mixed chlorophyll-anthocyanin dye from C. fruticosa (42%).
    Matched MeSH terms: Coloring Agents/chemistry*
  15. Al-Amrani WA, Lim PE, Seng CE, Wan Ngah WS
    Bioresour Technol, 2013 Sep;143:584-91.
    PMID: 23835263 DOI: 10.1016/j.biortech.2013.06.055
    Bioregeneration of mono-amine modified silica gel (MAMS) adsorbent loaded with Acid Orange 7 (AO7), Acid Yellow 9 (AY9) and Acid Red 14 (AR14), respectively, was investigated under two different operational conditions, namely absence/presence of sucrose/bacto-peptone as the co-substrate and different biomass acclimation concentrations. The results revealed that the AY9- and AR14-loaded MAMS adsorbents could almost be completely bioregenerated but only in the presence of co-substrate whereas the bioregeneration of AO7-loaded MAMS could achieve up to 71% in the absence of the co-substrate. These differences could be related to the structural properties of the investigated azo dyes. In addition, the results showed that the bioregeneration duration of AO7-loaded MAMS could be progressively shortened by using biomass acclimated to increasingly higher AO7 concentration. However, the bioregeneration efficiencies were found to be relatively unchanged under different biomass acclimation concentrations.
    Matched MeSH terms: Coloring Agents/chemistry*
  16. Al-Amrani WA, Lim PE, Seng CE, Ngah WS
    Water Res, 2012 Dec 1;46(19):6419-29.
    PMID: 23062787 DOI: 10.1016/j.watres.2012.09.014
    In this study, the operational factors affecting the bioregeneration of AO7-loaded MAMS particles in batch system, namely redox condition, initial acclimated biomass concentration, shaking speed and type of acclimated biomass were investigated. The results revealed that with the use of mixed culture acclimated to AO7 under anoxic/aerobic conditions, enhancement of the bioregeneration efficiency of AO7-loaded MAMS and the total removal efficiency of COD could be achieved when the bio-decolorization and bio-mineralization stages were fully aerated with dissolved oxygen above 7 mg/L. Shorter duration of bioregeneration was achieved by using relatively higher initial biomass concentration and lower shaking speed, respectively, whereas variations of biomass concentration and shaking speed did not have a pronounced effect on the bioregeneration efficiency. The duration and efficiency of bioregeneration process were greatly affected by the chemical structures of mono-azo dyes to which the biomasses were acclimated.
    Matched MeSH terms: Coloring Agents/chemistry
  17. Alkarkhi AF, Lim HK, Yusup Y, Teng TT, Abu Bakar MA, Cheah KS
    J Environ Manage, 2013 Jun 15;122:121-9.
    PMID: 23570974 DOI: 10.1016/j.jenvman.2013.03.010
    The ability of aluminum coagulant extracted from red earth to treat Terasil Red R (disperse) and Cibacron Red R (reactive) synthetic dye wastewater was studied. The effects of extractant concentration, soil-to-volume of extractant ratio, and the types of extracting agents (NaOH vs. KCl) on the concentration of aluminum extracted were also investigated. In addition, the efficiency of extracted aluminum was compared with aluminum sulfate, in terms of its capability to reduce the chemical oxygen demand (COD) and to remove synthetic color. Factorial design was applied to determine the effect of selected factors on the amount of aluminum extracted from red earth (i.e., pH, dose of coagulant, type of coagulant on COD reduction, and color removal). It was found that only selected factors exhibited a significant effect on the amount of aluminum extracted from red earth. It was also determined that all factors and their interactions exhibited a significant effect on COD reduction and color removal when applying the extracted aluminum in a standard coagulation process. The results were also compared to aluminum sulfate. Furthermore, NaOH was found to be a better extractant of aluminum in red earth than KCl. Therefore, the best extracting conditions for both extractants were as follows: 2 M NaOH and in a 1:5 (soil/volume of extractant) ratio; 1 M KCl and 1:5 ratio. In treating synthetic dye wastewater, the extracted coagulant showed comparable treatment efficiency to the commercial coagulant. The extracted coagulant was able to reduce the COD of the dispersed dye by 85% and to remove 99% of the color of the dispersed dye, whereas the commercial coagulant reduced 90% of the COD and removed 99% of the color of the dispersed dye. Additionally, the extracted coagulant was able to reduce the COD of the reactive dye by 73% and to remove 99% of the color of the reactive dye. However, the commercial coagulant managed to reduce the COD of the reactive dye by 94% and to remove 96% of the color for the reactive dye.
    Matched MeSH terms: Coloring Agents/chemistry*
  18. Alwash AH, Abdullah AZ, Ismail N
    J Hazard Mater, 2012 Sep 30;233-234:184-93.
    PMID: 22831996 DOI: 10.1016/j.jhazmat.2012.07.021
    A new heterogeneous catalyst for sonocatalytic degradation of amaranth dye in water was synthesized by introducing titania into the pores of zeolite (NaY) through ion exchange method while Fe (III) was immobilized on the encapsulated titanium via impregnation method. XRD results could not detect any peaks for titanium oxide or Fe(2)O(3) due to its low loading. The UV-vis analysis proved a blue shift toward shorter wavelength after the loading of Ti into NaY while a red shift was detected after the loading of Fe into the encapsulated titanium. Different reaction variables such as TiO(2) content, amount of Fe, pH values, amount of hydrogen peroxide, catalyst loading and the initial dye concentration were studied to estimate their effect on the decolorization efficiency of amaranth. The maximum decolorization efficiency achieved was 97.5% at a solution pH of 2.5, catalyst dosage of 2 g/L, 20 mmol/100 mL of H(2)O(2) and initial dye concentration of 10 mg/L. The new heterogeneous catalyst Fe/Ti-NaY was a promising catalyst for this reaction and showed minimum Fe leaching at the end of the reaction.
    Matched MeSH terms: Coloring Agents/chemistry*
  19. Anasdass JR, Kannaiyan P, Gopinath SCB
    Biotechnol Appl Biochem, 2022 Dec;69(6):2780-2793.
    PMID: 35293654 DOI: 10.1002/bab.2323
    We demonstrate a green chemistry approach to synthesize narrow-sized zerovalent iron (nZVI) nanoparticles using Artocarpus heterophyllus Lam. leaf extract as reducing and capping agent. The produced nZVI was characterized by various instrumental methods including ultraviolet-visible spectra, transmission electron microscopy, vibrating sample magnetometer (VSM), X-ray diffraction, and Fourier transform infrared spectroscopy. Based on the electron microscopy observations, the particle size was estimated to be ∼30 nm. In VSM, the saturation point of magnetization was observed to be 0.6 emu g-1 under a magnetic field of 0 ± 30 kOe. The synthesized nZVI was amorphous in nature as per the XRD results. The catalytic activity of the nZVI was employed for the catalytic reduction of 4-nitrophenol (4-NP) and decoloration of textile dyes such as methylene blue, methyl orange, and malachite green, respectively. The proposed nZVI synthesis method exhibited better catalytic performance toward reduction of 4-NP and degradation of dyes within 4 min for 0.1 mg of catalyst. Moreover, the synthesized catalyst nZVI can be recoverable and reutilized in many cycles without loss of its significant catalytic activity. The synthesized nZVI could be a promising material to treat industrial wastewater via profitable, sustainable, and ecofriendly approaches.
    Matched MeSH terms: Coloring Agents/chemistry
  20. Anezaki K, Kannan N, Nakano T
    Environ Sci Pollut Res Int, 2015 Oct;22(19):14478-88.
    PMID: 24809497 DOI: 10.1007/s11356-014-2985-6
    This study reports the concentrations and congener partners of polychlorinated biphenyls (PCBs) in commercially available paints. Polycyclic-type pigments containing dioxazine violet (pigment violet (PV) 23, PV37) and diketopyrrolopyrrole (PR254, PR255) were found to contain PCB-56, PCB-77, PCB-40, PCB-5, and PCB-12, and PCB-6, PCB-13, and PCB-15, respectively, as major congeners. Dioxazine violet is contaminated with by-products during synthesis from o-dichlorobenzene, which is used as a solvent during synthesis, and diketopyrrolopyrrole is contaminated with by-products during synthesis from p-chlorobenzonitrile. The concentration of PCBs in paint containing PV23 or PV37 was 0.050-29 mg/kg, and toxic equivalency (TEQ) values ranged 1.1-160 pg-TEQ/g. The concentration of PCBs in paint containing PR254 or PR255 was 0.0019-2.4 mg/kg. Naphthol AS is an azo-type pigment, and PCB-52 was detected in paint containing pigment red (PR) 9 with 2,5-dichloroaniline as its source. PCB-146, PCB-149, and PCB-153 were identified from paint containing PR112 produced from 2,4,5-trichloroaniline, as major congeners. These congeners have chlorine positions similar to aniline, indicating that these congeners are by-products obtained during the synthesis of pigments. The concentrations of PCBs in paints containing PR9 and PR112 were 0.0042-0.43 and 0.0044-3.8 mg/kg, respectively. The corresponding TEQ for PR112 was 0.0039-8.6 pg-TEQ/g.
    Matched MeSH terms: Coloring Agents/chemistry
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