Dye Removal Capacity Research Articles

Carbon nanotubes-reinforced preparation of flat MoS2 nanomaterials: Co-enhancement of acoustic exfoliation efficiency and dye removal capacity

A novel and effective preparation technology was developed to prepare ultrathin molybdenum disulfide (MoS2) crystals with a high yield of the top-down exfoliation. Multidimensional carbon nanotubes (MWCNTs) were selected to be an assistant to enhance the effect of the traditional ultrasonic exfoliation efficiency. The rough and messy tubes strengthened the shear force in some parts during the acoustic treatment, which helped to weaken the van der Waals force between the MoS2 layers. Excitingly, this high-efficiency strategy can increase the dispersion concentration of nanosheets by 15 times compared to the traditional acoustic production, which represented the preparation yield was improved greatly. It is found that the addition of MWCNTs not only facilitated the exfoliation efficiency of bulk material but also indirectly improved the adsorption of malachite green (MG) in wastewater. With a maximum removal capacity of 87.80 mg g−1, the adsorption ability of the nanotubes-reinforced layered adsorbent was effectively strengthened. In addition, the performance of reproducibility, stability, functioning free radical types, and the adsorption models were systematically studied.

Highly Effective Covalently Crosslinked Composite Alginate Cryogels for Cationic Dye Removal.

Currently, macroporous hydrogels have been receiving attention in wastewater treatment due to their unique structures. As a natural polymer, alginate is used to remove cationic dyes due to its sustainable features such as abundance, low cost, processability, and being environmentally friendly. Herein, alginate/montmorillonite composite macroporous hydrogels (cryogels) with high porosity, mechanical elasticity, and high adsorption yield for methylene blue (MB) were generated by the one-step cryogelation technique. These cryogels were synthesized by adding montmorillonite into gel precursor, followed by chemical cross-linking employing carbodiimide chemistry in a frozen state. The as-prepared adsorbents were analyzed by FT-IR, SEM, gel fraction, swelling, uniaxial compression, and MB adsorption tests. The results indicated that alginate/montmorillonite cryogels exhibited high gelation yield (up to 80%), colossal water uptake capacity, elasticity, and effective dye adsorption capacity (93.7%). Maximum adsorption capacity against MB was 559.94 mg g−1 by linear regression of Langmuir model onto experimental data. The Pseudo-Second-Order model was fitted better onto kinetic data compared to the Pseudo-First-Order model. Improved porosity and mechanical elasticity yielding enhanced dye removal capacity make them highly potential alternative adsorbents compared to available alginate/montmorillonite materials for MB removal.

Nanoporous Carbon from Water Hyacinth via Hydrothermal Carbonization assisted Chemical Activation for Dye adsorption

Nanoporous carbon was successfully prepared by hydrothermal carbonization with chemical activation using water hyacinth as a raw material. The porous carbon was produced for the adsorption of methylene blue (MB), which is an organic pollutant in wastewater from several industries. The effect of various parameters such as pH, dye concentration and adsorption period time on dye removal were studied. The highest removal efficiency of MB obtained using WH nanoporous carbon was approximately 96.8-99.9% within an adsorption time between 10 and 30 min. The dye removal capacity increased with increasing of period time during the adsorption test. Moreover, the adsorption kinetics of MB during adsorption process was explained by the Langmuir and Freundlich adsorption isotherms.

Castor Leaves-Based Biochar for Adsorption of Safranin from Textile Wastewater

The prospect of synthesizing biochar from agricultural wastes or by-products to utilize them as a promising adsorbent material is increasingly gaining attention. This research work focuses on synthesizing biochar from castor biomass (CBM) and evaluating its potential as an adsorbent material. Castor biomass-based biochar (CBCs) prepared by the slow pyrolysis process at different temperatures (CBC400 °C, CBC500 °C, and CBC600 °C for 1 h) was investigated for the adsorption of textile dye effluents (safranin). The pyrolysis temperature played a key role in enhancing the morphology, and the crystallinity of the biochar which are beneficial for the uptake of safranin. The CBC600 adsorbent showed a higher safranin dye removal (99.60%) and adsorption capacity (4.98 mg/g) than CBC500 (90.50% and 4.52 mg/g), CBC400 (83.90% and 4.20 mg/g), and castor biomass (CBM) (64.40% and 3.22 mg/g). Adsorption data fitted better to the Langmuir isotherm model than to the Freundlich isotherm model. The kinetics of the adsorption process was described well using the pseudo-second-order kinetic model. The study on the effect of the contact time for the adsorption process indicated that for CBC600, 80% dye removal occurred in the first 15 min of the contact time. After three regeneration cycles, CBC600 exhibited the highest dye removal efficiency (64.10%), highlighting the enhanced reusability of CBCs. The crystalline patterns, functional binding sites, and surface areas of the prepared CBCs (CBC400, CBC500, CBC600) were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area measurements, respectively.

Removal of crystal violet by Cu-chitosan nano-biocomposite particles using Box–Behnken design

Copper nanoparticles (CuNPs) impregnated biocomposites (Cu/chit-NBC) were prepared and characterized by the state-of-the-art analytical techniques. The CuNPs were in the average size ranges of 45.6–63.7 nm and 86.4 nm as confirmed by scanning electron microscopy and dynamic light scattering, respectively. To decolorize the crystal violet from the aqueous medium, fabricated Cu/chit-NBC was applied as an adsorbent. Box–Behnken design using three independent variables was adopted to optimize the Crystal Violet (CV) decolorization process. Under the optimum conditions of temperature 42.7 °C, pH 9.5, and 149.9 mg L−1 dose of adsorbent, 99.7 ± 0.2% decolorization was observed. Cu/chit-NBC also showed a very high dye removal capacity in simulated industrial textile effluents of around 99.7 ± 0.2%. The CV decolorization was consistent with pseudo-second-order kinetics and best fitted with the Freundlich adsorption isotherm. The nature and the potential processes involved in interactions between the CV and the nano-bioadsorbents during discoloration have been discussed in this paper.

Fabrication of magnetic cerium-organic framework-activated carbon composite for charged dye removal from aqueous solutions

The presence of synthetic dyes in water leads to health and ecological concerns due to their toxic and carcinogenic effects. For the remediation of coloured wastewater, we have fabricated a Ce-MOF@Fe3O4@activated carbon composite. The composite showed a ∼97–98% removal of indigo carmine and methylene blue at pH 7, whereas it was ∼83–85% for activated carbon. The adsorption and kinetic data followed the Temkin and Elovich models, respectively. Which suggested the involvement of physicochemical forces in the adsorption process. The thermodynamic study confirmed the adsorption process to be endothermic, where the adsorption performance improved with the increasing temperature. The increased intensity of the band at 824 cm−1 (CH) and 1004 cm−1 (aromatic CC) in the Raman spectra confirmed the adsorption of dyes onto the adsorbent. Dye adsorption was further confirmed by the N 1s peak at 400 eV for CNC in the dye-adsorbed composite. The shift in the binding energy of Fe 2p and Ce 3d peaks by 0.3–0.4 eV concluded the involvement of electrostatic and cation-π interactions in the adsorption process. A ∼90–98% dye removal capacity of the adsorbent even in the fourth cycle made it a highly stable and reusable adsorbent for remediation of coloured wastewater.

Pyrochlores: oxygen-rich moieties as ceramic fillers in uplifting the antifouling property and dye removal capacity of polymeric membranes

Application of nanostructured polymeric membranes for wastewater treatment is growing exceptionally because of their tunable functionalities, size, composition and morphology which offer immense opportunities for wastewater treatment. Here, for the first time, pyrochlore-type ternary metal oxides are explored as ceramic fillers to prepare mixed matrix membranes (MMMs)/polymeric nanocomposite membranes because of its affinity to water and oxygen. The effect of yttrium titanate (Y2Ti2O7) for the fabrication of polysulfone (PSF) MMMs is examined in terms of hydrophilicity, permeability, protein separation, dye removal and antifouling property. The synthesized pyrochlore oxides and the prepared MMMs are characterized using various techniques. The results show that the PSF MMMs manifest an enhancement in hydrophilicity, permeability and dye removal capacity upon addition of oxygen rich Y2Ti2O7 ceramic species into PSF membrane matrix. The PSF MMM with 1 wt% ceramic loading exhibited remarkable PWF (104 L/m2h), higher fouling resistance ratio and larger permeate flux recovery ratio (96%) compared to 27 L/m2h PWF and 40.57% FRR obtained for the pristine PSF membrane, respectively. Furthermore, significantly higher rejection of Congo red dye (100%), Pb2+ (98%) and Cd2+ (99%) heavy metal ions was achieved for mixed matrix membrane. Thus, Y2Ti2O7 ceramic species can open up new possibilities in enhancing the overall performance of the MMM for separation applications.

Removal of Malachite Green Dye using Keggin Polyoxometalate Intercalated ZnAl Layered Double Hydroxide

The ZnAl Layered double hydroxides (LDHs) have been successfully synthesized by the coprecipitation method, followed by intercalation using Keggin ion of α-dodecatungstosilicic acid [α-SiW12O40]4- to form ZnAl-[α-SiW12O40] LDHs. The prepared ZnAl-[SiW12O40] LDHs were characterized by using X-Ray, FTIR, and BET surface area analyses, which were, then, used as adsorbents of malachite green dye from aqueous solution. The synthesized ZnAl LDH showed a typical diffraction peak of the layered compound at 11o (003) with an interlayer space of 8.59 Å. After intercalation, it was recorded that the interlayer space of ZnAl-[SiW12O40] LDH increased to 10.65 Å. Moreover, the specific surface area of the intercalated LDH increased from 1.9685 to 14.0422 Å. The adsorption study revealed that the adsorption capacity of ZnAl-[SiW12O40] LDH toward malachite green dye was higher (37.514 mg.g-1) than the pristine ZnAl LDH (32.845 mg.g-1). The adsorption kinetics study showed that malachite green adsorption onto both pristine and intercalate LDH followed the pseudo-2nd-order model. The adsorption thermodynamic investigation indicated that adsorption of malachite green onto ZnAl-[SiW12O40] LDH was a spontaneous process and was classified as physical adsorption with activation energy ranging from 10.074 to 15.476 kJ.mol-1. HIGHLIGHTS ZnAl LDH intercalated by Keggin ion has been successfully synthesized by facile coprecipitation followed by ion exchange method The basal spacing of the intercalated ZnAl LDH increased up to 10.65 A The intercalated ZnAl LDH exhibited higher adsorption capacity for malachite green dye removal compared with the original ZnAl LDH

High-efficient removal of organic dyes from model wastewater using Mg(OH)2-MnO2 nanocomposite: Synergistic effects of adsorption, precipitation, and photodegradation

• Hierarchical Mg(OH) 2 -MnO 2 nanocomposite (MMNC) was successfully synthesized. • The MMNC exhibits a breakthrough dye removal capacity. • Different removal mechanisms for different concentrations of dye. • The MMNC exhibits excellent visible light photocatalytic activity. • Synergistic effects of adsorption, precipitation, and photocatalysis for dyes removal. Hierarchical Mg(OH) 2 -MnO 2 nanocomposite (MMNC) was successfully synthesized by a facile water-bath method, and further applied to Congo red (CR) and methyl orange (MO) removal. Batch experiments revealed that the maximum removal capacity of the nanocomposite to CR and MO reached 17,100 and 7300 mg g −1 , respectively. The CR removal mechanism was systemically investigated by FESEM, XRD, EDX and XPS techniques. The results showed that the CR removal proceed mainly through chemisorption on MMNC at low concentration. However, at high concentration, Mg 2+ will release from the nanocomposite and react with CR to form a precipitate (Mg-CR), leading to a huge removal capacity. Moreover, MMNC also exhibits excellent performance for photodegradation of CR under visible light irradiation. The active species trapping experiments revealed holes in MMNC and superoxide radical anions as the major active species responsible for photodegradation of CR. The synergistic effects of adsorption, precipitation, and photodegradation enable higher CR removal efficiency, making Mg(OH) 2 -MnO 2 nanocomposite an ideal material for dyes removal from water samples in both low concentration and scabrous high concentration dye-containing wastewater scenarios.

Preparation of magnetite-nanoparticle-decorated NiFe layered double hydroxide and its adsorption performance for congo red dye removal

Magnetite-nanoparticle-decorated NiFe LDH (MNPs@NiFe LDH) has been synthesized by the coprecipitation method followed by subsequent hydrothermal treatment. Material characterization was conducted using XRD, FTIR, SEM, BET surface area, and TG-DTA. MNPs@NiFe LDH exhibited high crystallinity, where the MNPs are uniformly distributed on its surface. MNPs@NiFe LDH showed higher adsorption capacity for congo red dye removal from an aqueous solution (79.6 mg/g). A further adsorption study, kinetics, isotherm, and thermodynamic indicated that the adsorption mechanism is governed by ionic interaction between the positively charged surface of the LDH and negatively charged dye molecules.

Dye removal by laccase-functionalized micromotors

Laccase-based poly(3,4-ethylenedioxythiophene)-polypyrrole/Pt (PEDOT-PPy-COOH/Pt) micromotors were electrosynthesized, characterized and applied for the decolorization of azo dyes widely used in the textile industry and found in textile wastewater. These laccase-based micromotors, due to their self-propulsion capabilities, were successfully used for the degradation of dyes by the improved activity of the on-the-fly immobilized laccase enzyme compared to that of the free enzyme. The Pt layer of the micromotor produced O2 by breaking down H2O2 and enabled the micromotor to move, while the carboxyl groups in the pyrrole units were used for the binding of laccase enzyme effectively, using the EDC/NHS coupling reaction. Enzyme stability studies were carried out, showing improved stability of the on-board immobilized enzyme at different pH and temperature conditions without a significant loss in affinity to the substrate. The overall dye removal capacity of the laccase-functionalized micromotors was demonstrated using dyes with 76–94% of decolorization efficiencies in comparison with those found using the free enzyme approach with lower decolorization efficiencies of about 34–55%.

Mechanistic study on methyl orange and congo red adsorption onto polyvinyl pyrrolidone modified magnesium oxide

This study reported a new water stable magnesium oxides (MgO) composite with polyvinyl pyrrolidone (PVP) prepared by one-pot hydrothermal method for the efficient elimination of both methyl orange and congo red from aqueous solutions. The as-prepared composite material shows new exposed crystalline surfaces and additional peaks for hydrogen bond formation which are confirmed from FTIR and X-ray diffraction analysis. The surface area of MgO-PVP composite (85 m2 g−1) was clearly higher than plain MgO (67 m2 g−1). The dye removal capacity of MgO-PVP composite was significantly higher than plain MgO. The adsorption mechanism study illustrated that the dye removal by MgO-PVP composite not only due to the electrostatic force of attraction, but also involved the ion exchange amid hydroxide group and dye molecules. The adsorption kinetic mechanism of dyes was mainly controlled by film diffusion, and pseudo-second-order kinetic equation was found to be best applicable to the current experiential data. Langmuir and DR isotherms were well fitted with current experimental results. The adsorption of methyl orange and congo red onto the composite was also conducted as a function of initial concentration, pH of solution, temperature of the solution and adsorbent dosage. Dye adsorption capacity was decreased with the increasing of initial pH value. The negative values of (∆G) for both the dyes show the spontaneous adsorption process.

Cost effective biosynthetic approach for graphene exhibiting superior sonochemical dye removal capacity

Green synthesis of graphene using leaf extracts as sustainable reducing and capping agents is a thrust area of research owing to its simplicity, eco-friendly nature and the ease of access to graphene. Moringa (Moringa oleifera Lam) plant is widely cultivated in India owing to its important medicinal and nutritional values. Inspired by these reports, herein we report a simple, green and economic synthesis of graphene, Moringa leaf extract employed reduced graphene oxide (MRGO) with excellent dye removal efficiencies. The MRGO is prepared by refluxing a mixture of aqueous dispersion of graphene oxide and Moringa leaf extract for 10 h. Further, we elucidated the role of synthesized MRGO in the removal of methylene blue (MB) and rhodamine B (RB) dyes through the sonochemical method. This as-synthesized material exhibited excellent dye removal efficiencies of about 93% and 87% against MB and RB dyes, respectively. Graphene with huge surface area expedited the better adsorption of dye molecules, thus, facilitated the better removal of the latter. Therefore, the superior dye removal efficiencies of MRGO were attributed to its adsorption capacity. This cost-effective synthetic approach of MRGO nanomaterial has a great potential for the innovative applications in water purification technology and find its place in further industrialization.

Flower-like Mg/Fe-layered double oxide nanospheres with ultrahigh adsorption efficiency for anionic organic dyes

Flower-like Mg/Fe-layered double oxide (Mg/Fe-LDO) nanospheres were synthesized using a facile one-step hydrothermal method and applied to remove anionic organic dyes, namely, Congo red (CR) and methyl blue (MB) with excellent adsorption efficiency. The Mg/Fe-LDO nanospheres showed over 99% removal efficiency within 25 min and 5 min for CR and MB, respectively. The calculated maximum removal capacities for CR and MB were 1250 mg g−1 and 2000 mg g−1 at 298 K, respectively. The removal of such large quantities of organic dyes was attributed to the chemical adsorption between anionic CR and MB dye molecules and cationic Mg/Fe-LDO nanospheres through strong electrostatic interactions. Moreover, the reusability test results showed that Mg/Fe-LDO, as an efficient adsorbent, is stable for at least five cycles with over 99% dye removal efficiency. Therefore, it is believed that the excellent dye removal capacities, recycling ability, and facile synthesis of Mg/Fe-LDO nanospheres will facilitate their practical application in cost-effective wastewater purification.

The Removal of Methylene Blue and Congo Red Dyes from Aqueous Solution by Using Sulfonated Carbon Derived Fishbone

In the world, the dyes pollutant from industrial activity is big issue that must be sought the solution. Among of dyes pollutants were methylene blue (MB) and congo red (CR). In this research have been conducted the removal of methylene blue and congo red onto sulfonated carbon derived fishbone (SCFB) as adsorbent from aqueous solution. The preparation steps of SCFB adsorbent involved the sulfonation (H2SO4; 1M) of fishbone powder for 6 h, by stirrer at room temperature, and followed by carbonization at 500 °C for 2 h. The physical properties of the adsorbents were characterized using Fourier Transform Infrared, X-Ray Diffraction (XRD), and nitrogen adsorption-desorption studies. The dye removal study using SCFB adsorbent was carried out by varying contact time and initial dye concentration. The kinetics models were determined by the effects of contact time. The adsorption isotherms were tested to isotherm Langmuir and Freundlich with a base on the effect of initial dye concentration. The result showed that The removal of MB and CR dyes using SCFB adsorbent fitted a pseudo-second-order kinetic models. The maximum dye removal capacity of SCFB was 128.2 mg g−1 for CR and 35.7 mg g− 1 for MB. Base on the maximum dye removal capacity, the SCFB can be considered as good adsorbent to remove dyes pollutant from environment.

Electrospun chitosan/polyvinyl alcohol nanocomposite holding polyaniline/silica hybrid nanostructures: An efficient adsorbent of dye from aqueous solutions

In this work, the addition of a novel polyaniline (PANI)/silica (SiO2) nanostructure (PSn) in chitosan/polyvinyl alcohol nanofibers (CP) was evaluated to enhance the dye removal capacity of CP. Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS) results confirmed the chemical grafting of SiO2 on PANI nanoparticles. Brunauer-Emmett-Teller (BET) results showed a specific surface area of 61 m2 g−1 for the PSn filled CP nanofiber (CP-PSn). FE-SEM and EDS-elemental mapping results showed the uniform dispersibility of PSn in CP nanofibers. After the addition of PSn into CP, the adsorption capacity of CP increased from 48 to 110 mg g−1 (from 0.069 to 0.158 mmol g−1), 40 to 90 mg g−1 (from 0.122 to 0.274 mmol g−1), and 31 to 45.2 mg g−1 (from 0.097 to 0.141 mmol g−1) for Congo red (CR), methyl orange (MO), and methylene blue (MB) dyes, respectively. The optimum anionic dye (CR and MO) uptake was observed at pH 5, while for the cationic dye (MB), the optimum uptake was detected at pH 9. The isotherm experiments results showed that the Sips isotherm model could well describe the adsorption process (R2 > 0.98). Thermodynamic studies at 298 and 328 K verified that the adsorption process is spontaneous with ΔG ranging between −10.44 and − 2.83 kJ mol−1. Also, ΔH was found to be 34.16, 22.25, and 17.05 kJ mol−1 for CR, MO, and MB adsorption, respectively. The highest recovery after 5 cycles was observed for a sodium hydroxide solution (NaOH, 0.1 M), which were 74, 68, and 55% of the adsorption capacity of the first cycle for CR, MO, and MB dyes, respectively.

Optimization of Congo red dye adsorption from wastewater by a modified commercial zeolite catalyst using response surface modeling approach.

In the present work, Zeolite A was modified by using hexadecyltrimethylammonium bromide (HDTMABr) for adsorption of the Congo red (CR) dye from synthetic aqueous solutions. The Modified Zeolite A (MZA) was characterized by XRD, SEM, and FTIR. The influence of solution pH (in the 4-12 range), ionic strength (0.1-1 M), contact time (180 min), initial CR concentration (20-60 mg/L), temperature (24-36 °C), and an adsorbent dose (1-3 g m/L) on the % dye removal and adsorbent capacity were studied. A combined effect of the initial CR concentration and temperature on the CR removal % by MZA was also studied by applying response surface methodology (RSM). Experimental values were in a good agreement with those predicated by a second-order quartic model. A maximum of 99.24% dye removal and adsorbent capacity of 21.11 mg/g was achieved under the following conditions: pH = 7, initial CR concentration = 60 mg/L, temperature = 24 °C, ionic strength = 0.1 M, adsorbent dose = 3 g/L and 90 min contact time. The equilibrium data were subjected to the Langmuir, Freundlich and Temkin isotherms, with the latter providing the best fit while kinetic adsorption studies were conducted by applying three models. The results indicated that the removal process was best described by the pseudo-second-order model. The present study demonstrates that modified MZA can be utilized for the highly efficient CR dye removal.

Cucurbituril-Functionalized Nanocomposite as a Promising Industrial Adsorbent for Rapid Cationic Dye Removal.

A supramolecular cucurbit[6]uril (CB[6])-enriched magnetic montmorillonite (CBCM) nanocomposite was prepared and characterized. CB[6] played a prominent role as a capping agent, helping in better distribution of the nanoparticles, and as a binder between nanoparticles. Montmorillonite provided structural stability and fortified ultrafast adsorption toward dyes. Its application in the removal of cationic dyes from wastewater was systematically assessed. Process parameters such as pH, initial dye concentration, dosage, temperature, and time were optimized. Kinetics and isotherms of the process were described using pseudo-second-order kinetics and the Langmuir isotherm, respectively. CBCM exhibited rapid dye removal capacity in short reaction times with qmax of 199.20, 78.31, and 55.62 mg g–1 and K2 of 0.0281, 0.0.0823, and 0.0953 L mg–1 min–1 for crystal violet, methylene blue, and rhodamine B, respectively. Benefiting from the synergetic effects of montmorillonite surface hydrophobicity, abundant carbonyl groups of CB[6], and magnetic properties of copper ferrite, CBCM demonstrated outstanding dye removal capacity, negligible leaching at saturation, and high tolerance toward harsh conditions. This intrinsic nature is expedient in prolonged industrial operations. To demonstrate industrial viability, syringe filtration and continuous flow fixed-bed column operations were validated. The CBCM fixed-bed column demonstrated stable dye removal efficiency with 10–100 mg mL–1 dye at 10–50 mL min–1 flow rates. Utilizing the magnetic and catalytic activities of the copper ferrite nanoparticles, CBCM was recycled using a magnet, regenerated, and reused for several cycles. CB[6] remarkably improved the performance of the nanocomposite and made it suitable for different effluent treatment techniques. This may pave a sustainable way toward the efficient onsite treatment of effluent at the industrial scale.

Effective removal of malachite green dye from aqueous solution in hybrid system utilizing agricultural waste as particle electrodes

A comparison study of an electrolytic, adsorption, and a novel hybrid method towards the removal of malachite green (MGD) dye from the aquatic environment utilizing agricultural biomass, Eucalyptus globulus seeds was examined. The synthesized material has been characterized by thermogravimetric analysis, SEM, FTIR, and XRD. The acid-modified biosorbent developed a microporous structure suggesting a suitable removal process of MDG. The hybrid method was carried in an indigenously designed three-phase three-dimensional electrolytic reactor with varying applied voltage (6, 9, and 12 V) with biosorbent serving as particle electrode. The hybrid method gave the highest removal rate at a voltage of 12 V, compared to other methods. Moreover, the dye removal capacity increased with increased voltage, and contact time was optimized at 15 min. The adsorption isotherm was well fitted with Freundlich isotherm and kinetic data represented pseudo-second-order. Intra particle diffusion studies suggested no interference with gradual adsorption from macropores to micropores. The removal efficiency of particles electrodes for 6, 9, and 12 V were 95, 97, and 99.8%, respectively. The higher removal of MDG towards the hybrid system may be assigned to the synergistic effect of electrolytic and adsorption systems. Regeneration studies indicated that the biosorbent can be reused up to ten times without appreciable loss of efficiency.

Synthesis of peanut-shell magnetized biocarbon for acid fuchsin dye removal

Abstract Magnetized bio carbon(MBC) and peanut shell activated carbon(PSAC) was produced from peanut shell biomass by chemical treatment. MBC was 99.35% effective in removal of acid fuchsin dye compared to 62% of PSAC and can be applied to real time adsorption of excess dye content. Further studies on MBC contact time and the biomass amount showed great influence on adsorption capacity. The biomass of 1 g and optimum contact time of 120 min at room temperature was sufficient enough to bring about good adsorption. Adsorption study was best explained by Freundlich isotherm. The kinetics followed a pseudo second order kinetics. Both results conclude that adsorption process is a physio-chemical adsorption process. The concentration of the dye analysed during the study decreased significantly during the experimental period, proving that MBC to be an excellent adsorbent. The adsorbent could be reused till five times without appreciable loss in dye removal capacity. Thus, the development of this efficient magnetized bio sorbent can be considered an eco-friendly and cost-effective approach for dye removal.