Elimination Of Chromium Research Articles

Enhanced elimination of chromium (VI) ions from wastewater with silica-mixed magnetic nanomaterial: isotherm and kinetic studies

Enhanced elimination of chromium (VI) ions from wastewater with silica-mixed magnetic nanomaterial: isotherm and kinetic studies

BioRicinus Communis Seed Extract was Used in the Green Manufacture of Zero-valent Iron Nanoparticles for Photocatalyst Elimination of Chromium

Zero-valent iron was produced in this work utilising BioRicinus communis seed extract. XRD, SEM, and TEM methods were used to characterise the physicochemical characteristics of the finished products. According to TEM analysis, the iron zero-valent nanomaterials with diameters ranging from 20 to 40 nm and shell-core architectures were successfully produced. XRD findings verified the existence of several organic compounds. The photoactivity of the product was investigated by reducing the contaminant. According to the test result, the inclusion of fruit extract as a nanoscale catalyst in the photocatalyst reduced the hexavalent chromium. According to photocatalyst results, when the particulate dose was 0.675 g/L, the trivalent chromium suffered from low was 100%. A pseudo-second-order solution describes this reaction's kinetics. At pH 3 and 0.5 g/L seed extract concentration, the kinetic rate constant is 0.4. As a result, the frequency of the photocatalyst was significantly increased, and a more significant amount of Cr (VI) was eliminated. The accessible sites became progressively constrained and overloaded with bichromate particles as the starting content of Cr (VI) was increased at a consistent dose. Changing the nanoparticle dosage may considerably boost the reaction rate, hence the effectiveness of a photocatalyst's Cr (VI) catalytic cycle.

Usefulness of the Biomass of Tobacco (Nicotiana tabacum) for The Elimination of Chromium (VI) from Polluted Waters

The tobacco plant is capable of accumulating heavy metals in its different parts, making it a good candidate for use in bioremediation, although there are few reports in which the biomass of this plant is used for the removal of heavy metals in solution. Also, cigarette residues are an environmental problem, so the use of these residues is an opportunity to obtain biomass for the removal of heavy metals from polluted environments. The objective of this work was to determine the removal capacity of Cr (VI) by commercial tobacco biomass, finding that 1 g of biomass removal 72 mg/L of the metal at 24 h, pH 2.0, 28 °C and 100 rpm, while at higher temperatures the removal is higher, and if the concentration of the metal is increased (1 g/L), its removal capacity is reduced, since 64.72% is removed at 24 h at 28 °C, although at 60 °C, 1 g/L is removal at 8 hours. If the concentration of the bioadsorbent is increased, the metal removal does not increase. Finally, 5 g of biomass eliminates 66.1% and 74% of Cr (VI) present in naturally contaminated soil (100 mg/g) and water (100 mg/L), respectively.

Efficient, fast, simple, and eco-friendly methods for separation of toxic chromium(VI) ions based on ion exchangers and polymer materials impregnated with Cyphos IL 101, Cyphos IL 104, or D2EHPA

In this study, we present the results of the first comparison of the elimination of toxic Cr(VI) ions, which are hazardous contamination of the environment, from aqueous solutions using ion exchangers (IEs) and polymer materials (PMs) impregnated with D2EHPA or ionic liquids (Cyphos IL 101 and Cyphos IL 104). Sorption of Cr(VI) ions and desorption from the formulated sorption materials were carried out. In comparison, classical solvent extraction was accomplished. Fourier transform infrared-attenuated total reflectance spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and atomic force microscopy (AFM) have been used for characterization of the structure of developed IEs and PMs. The highest efficiency of adsorption of Cr(VI) ions was obtained using PMs with ionic liquids (>82%). Desorption from these materials were also very efficient (>75%). On the contrary, the application of IEs allowed for obtaining the best results of both, sorption and desorption processes when using D2EHPA (75% and 72%, respectively). The application of PMs and IEs is part of the green chemistry, and the conducted elimination of chromium(VI) ions using developed materials allows for the conclusion that they can potentially be used on a larger scale, e.g., for the treatment of industrial wastewater rich in Cr(VI) ions.

Investigation and optimization the study of Hexavalent Chromium elimination efficiency by activated carbon prepared from modified rice husk with sorbic acid

The current work illustrates how successfully rice husk-activated carbon eliminates hexavalent chromium from aqueous solutions. The design of experiment (DOE) - response surface methodology (RSM) was utilized to build an appropriate experimental model. The experimental variables pH, contact length, and adsorbent dose were found, as well as their interactions and effects on Cr(VI) removal. The greatest result for Cr(VI) removal was obtained at pH = 2, agitation time of about 30.5 hours, and adsorbent dose = 4 g/l, with a starting hexavalent chromium content of 100 ppm. Hexavalent chromium removal is performed optimally under the parameters specified for these driving forces. ANOVA also demonstrated a strong coefficient of determination R2 > 99 %. Furthermore, Temkin isotherm and pseudosecond kinetic models with high R2 values were selected as useful for the inquiry. It illustrates that the removal of hexavalent chromium in studies is considered to follow a regular distribution of binding energies up to a given maximum binding energy. Furthermore, the rate of adsorption site occupancy is inversely proportional to the square of the number of unoccupied sites on the adsorbent.

Elimination of Chromium (Vl) from Industrial Effluent through the Utilization of Water Hyacinth weed

Biosorption is a physico-chemical binding of a substance to biological material. Water hyacinth has been successfully utilized for the removal of chromium (VI) from waste water samples. The plants were divided in to two part (i) root (ii) foliage. Each part was dried at 750 C for 48 hours and then its weighed was taken. The tissue samples weight then ash in the muffle-furnace at 3500 C for 5 hours. Ash samples were digested with acids (HNO3, HCl) and diluted with 100 ml of distilled water. The detection of chromium (VI) carried out by Atomic Adsorption Spectrophotometer (AAS). This method of removing chromium from water is cost-effective, eco-friendly, and has been shown to be effective in laboratory studies.

Removal of chromium from tannery industry wastewater using iron-based electrocoagulation process: experimental; kinetics; isotherm and economical studies

Chromium is a hazardous compound from industrial processes, known for its toxicity, mutagenicity, teratogenicity, and carcinogenicity. Chemical methods are efficient but cost-effective alternatives with reduced sludge are sought. Electro-coagulation, utilizing low-cost iron plate electrodes, was explored for factual tannery wastewater treatment in this manuscript. Operating parameters such as initial chromium concentration, voltage, electrode number, operating time, agitation speed and current density has been studied to evaluate the treatment effeciency. Under optimal conditions (15 V, 0.4 mA/cm2, 200 rpm, 330 ppm chromium, 8 iron electrodes with a total surface area of 0.1188 m2, 3 h), chromium elimination was 98.76%. Iron anode consumption, power use, and operating cost were 0.99 gm/L, 0.0143 kW-h/L, and 160 EGP/kg of chromium eliminated, respectively. Kinetics studies were pursued first-order reaction (97.99% correlation), and Langmuir isotherms exhibited strong conformity (Langmuir R2: 99.99%). A predictive correlation for chromium elimination (R2: 97.97%) was developed via statistical regression. At HARBY TANNERY factory in Egypt, industrial sewage treatment achieved a final chromium disposal rate of 98.8% under optimized conditions.

Exploring Tannery Solid Wastes as a Source of Animal Feed

This review delves into the processing of tannery solid waste, emphasizing fleshings and chromium-tanned leather waste. This paper centers on fat recovery, chromium elimination, and protein preservation, aiming to make them apt for animal consumption. This paper also assesses the potential of introducing such recycled products to the global market. Drawing on the literature from the past two decades, sourced comprehensively from Scopus and Web of Science, 36 articles were selected because of their significant contributions from leather production powerhouses such as India and Brazil. Fleshings have shown immense potential as animal feed, and the extraction of tallow and collagen from rawhide trimmings yields up to 98% and 93%, respectively. Fermented tannery fleshings, notably with Enterococcus faecium HAB01, also demonstrate strong antioxidant capabilities. The overarching consensus emphasizes the need for rigorous purification when dealing with chromium-containing wastes, addressing concerns tied to Cr (III) and Cr (VI). Furthermore, raw tannery fleshings stand out as a sustainable, cost-effective, and globally marketable solution for animal feed production.

Potential Elimination of Chromium (VI) by Chemically Biochar Derived from Pennisetum Setaceum

This study consisted of a novel potential adsorbent material that could efficiently remove chromium (VI) from aqueous solutions. The optimum operating conditions were investigated including pH, agitation period. In this research, biochar derived from fountain grass (Pennisetum setaceum) coated with glutaraldehyde-crosslinked chitosan and treated with succinic acid to add functional groups was used to create an eco-friendly sorbent (CPES). It demonstrated that 3.0 is the ideal pH for the Cr (VI) adsorption process. The equilibrium stirring time is 120 minutes. The Langmuir and Freundlich models have been used to examine experimental data. According to the results, and the Freundlich model performed a better fit of the result than the Langmuir one. Cr (VI) has a maximum adsorption capacity of 30.96 mg/g. The Gibbs free energy change (êG), enthalpy change (êH), and entropy change (êS) thermodynamic parameters were determined. The fact that êG was negative demonstrated that Cr (VI) adsorption onto the CPES adsorbent occurred spontaneously.

Porous g-C3N4 Nanosheets for On–Off–On Fluorescence Detection and Elimination of Chromium(VI) and Sulfite

Porous g-C₃N₄ Nanosheets for On–Off–On Fluorescence Detection and Elimination of Chromium(VI) and Sulfite

Elimination of Chromium(VI) and Vanadium(V) from Waters by Carboxymethylcellulose-Stabilized Amorphous Nanoscale Zero-Valent Iron

Elimination of Chromium(VI) and Vanadium(V) from Waters by Carboxymethylcellulose-Stabilized Amorphous Nanoscale Zero-Valent Iron

Introduction of CdO nanoparticles into graphene and graphene oxide nanosheets for increasing adsorption capacity of Cr from wastewater collected from petroleum refinery

Graphene and graphene oxide nanocomposites are promising and fascinating types of nanocomposites because of their fast kinetics, unique affinity for heavy metals, and greater specific area. Initially, in this study, a green, cost-effective and facile method was utilized to prepare G, GO, CdO, G-CdO, and CdO-GO nanocomposites by Azadirachta indica and then analyzed using UV–vis spectroscopy, Fourier-transform spectroscopy, Raman, X-ray diffraction and scanning electron microscope. The synthesized nanocomposites were explored for chromium elimination from wastewater collected from a petroleum refinery. CdO-GO, G-CdO nanocomposites showed remarkable adsorption capability of 699 and 430 mg g−1 which was higher than G (80 mg g−1), GO (65 mg g−1), and CdO (400 mg g−1). Based on the R2 (correlation coefficient) values, the kinetic statistics of Cr (VI) onto the G, GO, CdO, G-CdO, and CdO-GO were effectively obeyed by pseudo-second-order than by all other models. The R2 values for the five nano-bioadsorbents were extraordinarily high (R2 greater than 0.990) which ensured the chemisorption. This study ensured that the adsorptive removal rate of Cr (VI) is still greater than 85 % after repeated five cycles, suggesting that the produced nanomaterials are adsorbents with strong recyclability.

Biosorbent Efficacy of Groundnut Husk for the Elimination of Chromium from the Effluent of Mojo Tannery Industry, Ethiopia.

The present study aimed to assess the effects of raw (RGNH), ethanol-extracted (EEGNH), and acid-treated (ATGNH) groundnut (Arachis hypogaea L.) husk for removal of chromium from tannery effluent from the Mojo tannery industry, Ethiopia. The effects of biosorbent dose, agitation speed, and contact time of heavy metal on biosorbent were measured. The percentage removal of chromium was examined by a flame atomic absorption spectrophotometer (FAAS). Functional group characteristics of the biosorbents were analyzed using Fourier transform infrared spectra (FTIR). The results indicated that at low doses (2 g), acid-treated groundnut husk (ATGNH) exhibited the highest removal efficiency (89.93%), whereas at a high dose (4 g), the raw groundnut husk (RGNH) has a potential removal efficiency (91.03%). The least removal efficiency was displayed by ethanol-extracted groundnut husk (EEGNH) (65.43%) at a dose of 3 g. Relating to the contact time, the highest chromium removal (94.41%) was exhibited by ATGNH with a 1-hour contact time. However, as contact time increased from 2 to 4 hours, there was a general decrease in the efficiency of biosorption. The removal of chromium by RGNH and EEGNH increased as contact time increased from 1 to 3 hours. The highest chromium removal (90.02%) was observed with ATGNH at 160 rpm agitation speed.

Kinetics of the biosorptive removal of chromium from water using mycelial biomass of Aspergillus oryzae

Chromium is one of the highly toxic heavy metals and a chief pollutant in soil and water. Present study describes an efficient biosorption system for the chromium removal from water using mycelia of Aspergillus oryzae. The effect of different variables like pH, initial chromium conc., size of biomass and time of contact on the chromium uptake by A. oryzae was studied and it was found that absolute elimination of chromium from the aquous medium was achieved after 96 hrs of contact. The removal percentage of Cr(VI) was enhanced by increasing pH from 3.0 to 5.0 and then started decreasing. Similarly the removal of Cr(VI) was enhanced by increasing biomass concentration upto 0.7 g/50 mL chromium solution while this removal was decreased by increasing Cr(VI) concentration in the solution from 50 to 100 µg/mL. Langmuir and Freundlich models were applied to the data after experimentation and Freundlich equation was found to be better fitted to the data.

Hexavalent chromium elimination from wastewater by integrated micro-electrolysis composites synthesized from red mud and rice straw via a facile one-pot method

The widely spread chromium (Cr) contamination is rising environmental concerns, while the reutilization of agro-industrial by-products are also urgently demanded due to their potential risks. In this study, we prepared the integrated micro-electrolysis composites (IMC) through a facile one-pot method with red mud and rice straw. The effects of components relatively mass ratios as well as pyrolysis temperature were analyzed. The XRD, XPS, SEM, FTIR, and various techniques proved the IMC was successfully synthesized, which was also used to analyze the reaction mechanisms. In this study, the dosage of IMC, pH, adsorption time, and temperature of adsorption processes were explored, in the adsorption experiment of Cr(VI), dosage of IMC was 2 g/L (pH 6, 25 °C, and 200 rpm) for isothermal, while the concentration and contact time were also varied. According to the batch experiments, IMC exhibited acceptable removal capacity (190.6 mg/g) on Cr(VI) and the efficiency reached 97.74%. The removal mechanisms of adsorbed Cr(VI) were mainly elaborated as chemical reduction, complexation, co-precipitation, and physical adherence. All these results shed light on the facile preparation and agro-industrial by-products recycled as engineering materials for the heavy metals decontamination in wastewater.

Removal of Cr (III) from wastewater by using raw and chemically modified sawdust and corn husk

Abstract The contamination of water resources by heavy metals (HMs), mainly introduced by anthropogenic resources, has been considered as a serious environmental issue in the recent era. Therefore, the conventional methods for heavy metal removal have various drawbacks in terms of cost, toxicity, and efficiency. The novel study investigated the biosorption intensity of raw and chemically modified sawdust (SD) and corn husk (CH) to eliminate chromium (III) from the aqueous solutions. SD and CH were used as biosorbents and were treated chemically with sulfuric acid (H2SO4), sodium hydroxide (NaOH), and detergent powder. The biosorption potential was estimated based on percentage removal efficiency (% RE) of chromium (III) and the adsorption intensity (qmax). The characterization of surface morphology and functional groups of biosorbents was studied by SEM and FTIR. Moreover, the adsorption isotherm models (Langmuir and Freundlich), kinetic models (pseudo-first-order kinetics and pseudo-second-order kinetics), and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also assessed to predict the biosorption process. The results of % RE revealed that detergent-treated SD (DTSD) and detergent-treated CH (DTCH) showed highest % RE of 9.27 ± 0.15 (%) and 99.16 ± 0.08 (%) for elimination of chromium (III), respectively. Similarly, base-treated SD (BTSD) and base-treated CH (BTCH) exhibited 95.53 ± 0.18 (%) and 92.43 ± 0.22 (%) of % RE compared with 77.87 ± 1.64 (%) and 81.96 ± 0.34 (%) removal efficiency of acid-treated SD (ATSD) and acid-treated CH (ATCH), respectively. The raw SD (RSD) and raw CH (RCH) showed lower % RE of 23.68 ± 1.52 (%) and 35.52 ± 4.74 (%) for Cr (III) removal. Further, the porosity on the biosorbent's surface and attached functional groups increased after chemical treatment and this variation resulted in increased removal efficiency after chemical treatments. The Langmuir isotherm model and the Freundlich isotherm model were employed to predict the biosorption process, and both these models are best-fitted. The pseudo-second-order kinetic model was promising representative of the biosorption data. The process was endothermic and the parameters indicated that Cr (III) biosorbtion was thermodynamically favorable. Therefore, the obtained results highlighted that detergent-treatment enhanced the % RE, and DTSD and DTCH are highly efficient biosorbents for eliminating Cr (III) from aqueous solutions. Thus, detergent-treated biosorbents are proved to be a promising sustainable, eco-friendly, and cost-effective way to treat HMs from aqueous solutions as they utilize natural agriculture waste products and also handle issues related to excessive solid waste management.

Deep eutectic solvent assisted facile and efficient synthesis of nitrogen-doped magnetic biochar for hexavalent chromium elimination: Mechanism and performance insights

Dual-modification of biochar through magnetization and nitrogen-doping can greatly enhance the removal performance for Cr(VI). Deep eutectic solvent (DES), as a class of novel green solvent, has gained much attention in the research field of material science. In this study, a DES produced by complexing of FeCl3 and urea was adopted for the first time to assist the facile and efficient preparation of a nitrogen-doped magnetic biochar (NMBC) by using peanut shell (PS) as raw stock. The results indicated that FeCl3/urea-based DES could act as fine iron and nitrogen sources in the formation of NMBC. More importantly, the DES catalyzed the pyrolysis process of PS and promoted the pore development on biochar. The synthesized NMBC showed satisfactory removal efficiency for Cr(VI), with the adsorption process well depicted by Langmuir isotherm and pseudo-second-order kinetic models. The results revealed that iron species, nitrogen- and oxygen-containing groups in NMBC made great contributions to Cr(VI) capture. The comprehensive mechanism included pore-filling, electrostatic attraction, cation bridging, ion-exchange, reduction and surface complexation. The present study provides a new insight to guide the design of functional biochar for Cr(VI) decontamination from water.

Elimination of Chromium (VI) and Nickel (II) Ions in a Packed Column Using Oil Palm Bagasse and Yam Peels

The single-component adsorption of chromium (VI) and nickel (II) on oil palm bagasse (OPB) and yam peels (YP) in a packed bed column was explored and improved using a central 22-star T composite design. The temperature, bed height, and particle size were evaluated, and the optimized response variable was the removal efficiency. The remaining concentration of heavy metals in solution was determined by Ultraviolet–Visible and Atomic Absorption Spectroscopy. It was found that bioadsorbents have a porous structure, with the presence of functional groups such as hydroxyl, carboxyl, and amino, which favor adsorption processes, and that the adsorption mechanisms controlling the process is cation exchange, precipitation, and complexation on the exposed surface of the biomaterials. In the adsorption trials, removal percentages higher than 87% were obtained in all cases, showing better results in the removal of Cr(VI), and that particle size is the most influential factor. Maximum Cr(VI) capacities of 111.45 mg g−1 and 50.12 mg g−1 were achieved on OPB and YP, respectively, while for nickel values of 103.49 mg g−1 and 30.04 mg g−1 were obtained. From the adjustment of the breakthrough curve to the models, it was determined that the model best able to adjust the data was the Thomas model, and the thermodynamic parameters of Cr(VI) and Ni(II) removal suggest that the process on YP is endothermic, while on OPB it is exothermic. In both biomaterials, the process is controlled by spontaneous chemisorption with a great affinity of the active centers for the ions.

Accumulation of chromium in plants and its repercussion in animals and humans

The untreated effluents released from industrial operations have adverse impacts on human health, environment and socio-economic aspects. Environmental pollution due to chromium is adversely affecting our natural resources and ecosystem. Chromium is hazardous carcinogenic element released from spontaneous activities and industrial procedures. Chromium toxicity, mobility and bioavailability depend mainly on its speciation. Chromium mainly exists in two forms, first as an immobile, less soluble trivalent chromium [Cr(III)] species under reducing conditions whereas hexavalent chromium [Cr(VI)] as a mobile, toxic and bioavailable species under oxidizing conditions. Hexavalent chromium is more pernicious in comparison to trivalent form. Chromium negatively affects crop growth, total yield and grain quality. Exposure of chromium even at low concentration enhances its accretion in cells of human-beings and animals which may show detrimental health effects. Many techniques have been utilized for the elimination of chromium. The selection of the green and cost-efficient technology for treatment of industrial effluent is an arduous task. The present review highlights the problems associated with chromium pollution and need of its immediate elimination by suitable remediation strategies. Further, investigations are required to fill the gaps to overcome the problem of chromium contamination and implementation of sustainable remediation strategies with their real-time applicability on the contaminated sites.

Elimination of Chromium(Vi) and Vanadium(V) by Carboxymethylcellulose-Stabilized Amorphous Nanoscale Zero-Valent Iron

Elimination of Chromium(Vi) and Vanadium(V) by Carboxymethylcellulose-Stabilized Amorphous Nanoscale Zero-Valent Iron