Min Of Contact Time Research Articles

Bioremoval of boron from seawater using Leucaena leucocephala seed pods

ABSTRACT The paper reports Boron (B) uptake using Leucaena leucocephala seed pods (LLSP) as a pre-treatment for reverse osmosis seawater desalination. The process increases the quality of the membrane-entering nutrient water. The research investigated a new, low-cost biosorption technique for boron from Gaza shore on the Mediterranean Sea at a distance of 300 m from shore and 1 m deep. The maximum adsorption efficiency reached 85.7% at pH 12, 30 min contact time, and adsorbent dosage of 2 g/100 ml seawater. The initial and final concentration of boron was measured using Inductively Coupled Plasma (ICP). The Langmuir and Freundlich isotherms were applied to the adsorption data. The kinetic data for removal processes were fitted with the pseudo-second-order model.

Production of highly purified zirconium oxide from zircon mineral leach liquor using bis-(2-ethylhexyl) phosphate as a promising extractant

In this manuscript, efficiency of the used organic solvent for recovering, separating and producing highly purified zirconium oxide from zirconium chloride leach liquor of Rosetta white zircon concentrate was investigated. Zircon mineral was thermally decomposed with caustic soda, cooled, washed with distilled water and then dissolved in hydrochloric acid. Zirconium extraction efficiency reached 91.4% using 10% bis-(2-ethylhexyl) phosphate dissolved in kerosene, 15 min contact time and volume phase ratio O/A 1:1 after 3 stages. Zirconium re-extraction efficiency reached 99.95% using the following optimum conditions 4 molL−1 H2SO4 as an effective stripping agent, 15 min contact time and volume phase ratio O:A 1:1 after 2 stages. Finally, Zr (OH)4 was precipitated in presence and absence of H2O2 by NH4OH solution, filtrated, rinsed with double distilled H2O to remove any impurities several times and dehydrated at 200 °C for 2 h. From XRF and EDAX analysis the produced zirconium oxide in presence of H2O2 is purer than that produced in absence of H2O2.

Coliform Removal in Membrane Bioreactor and Disinfection during Hospital Wastewater Treatment

This study investigated coliform removal from hospital wastewater in a membrane bioreactor (MBR) and disinfection using either chlorine or ozone. A laboratory-scale MBR equipped with a hollow-fiber membrane module was operated with hydraulic retention times varied at 3 and 6 hours. The disinfection of MBR effluent was carried out using either chlorine or ozone with concentrations varied between 1 and 10 mg/l and contact time varied between 1 and 30 min. During 150 days of MBR operation, organic removal efficiencies averaged 96.5% and 97.7% for BOD and 73.6% and 84.1% during its operation at an HRT of 3 and 6 hours respectively. Simultaneously, 6.7 and 6.4 log reduction of total coliforms and 6.2 and 6.1 log reduction of E. coli were achieved under these respective HRT conditions. The use of chlorine for disinfection of MBR effluent could eliminate total coliforms and E. coli completely at >6 and 3 mg/L at 30 min contact time, whereas only >3 and 1 mg/L was required for ozone at the same contact time. There was a significant improvement of disinfection efficacy of solid-free MBR effluent compared to that of activated sludge effluent.

The optimum conditions of Titanium Recovery process from the Iraqi Bauxite Ore

The present work is especially concerned with the Iraqi bauxite ore that includes 4.1% of titanium element (Ti). The goal of this study is to investigate the effect of various parameters (concentration of acid, ratio of solid: liquid, stirring speed, contact time, and temperature) in order to determine the best conditions for the leaching and extraction of titanium element. All tests of leaching were conducted with different acids (HNO3, H2SO4, and H3PO4) with a ratio of solid: liquid from (1: 100) to (1: 8), the temperature of reaction from (25°C) to (50°C), period of time from (30 min) to (120 min), and speed of stirring from (400 rpm) to (1200 rpm). The best conditions were determined at (1: 100) solid: liquid ratio, (50°C) temperature, (4 M) HNO3 concentration, and (900 rpm) stirring speed. While, the titanium extraction was from leached solution by (trioctylphosphine oxide) (TOPO), tri-n-butyl phosphate (TBP), and di-2- ethylhexyl phosphoric acid (D2EHPA) dissolved in kerosene) with an organic/aqueous ratio of (1/1, 1/2, 1/3, 2/1, and 3/1); temperature of reaction and period of time are correspondingly from (25°C) to (55°C) and from (8 min) to (15 min), and speed of stirring (400 rpm). The best conditions were obtained when using (55°C) temperature, (50%) TOPO concentration, (15 min) contact time, (400 rpm) speed of stirring and (1/3) O/A ratio.

Treatment of industrial effluent to reclaim copper using adsorption technique

ABSTRACT Effluent generated during metal finishing in industries contains large amount of heavy metals, which get discharged into water bodies and creates environmental pollution as well as loss of metal values. Present studies report the adsorption of copper (Cu) from the effluent using Tulsion T-42 resin. Experiments were carried out for the adsorption of Cu from the effluent of Chemical and Mechanical Polishing (CMP) industries using cationic resin Tulsion T-42 (adsorbent). To get the optimized adsorption condition for copper the studies were carried out with varying process parameters i.e., contact time, adsorbent dose, pH, etc. Result of the batch experiments shows that 95% copper was adsorbed from the effluent containing 100 ppm copper using 0.1 g Tulsion T-42 in 50 mL feed solution at pH 4.0 in contact time of 30 min. The obtained data from Cu adsorption studies fitted well with Freundlich adsorption isotherm and followed second-order rate reaction. The 99% copper was found to be eluted from loaded adsorbent using 10% sulfuric acid in 60 min contact time. FT-IR result confirmed that complex with active sulphonic group of Tulsion T-42 was formed. The findings of the studies will be useful for the reclamation of copper from the waste water of metal finishing industries.

Manganese and nitrate removal from groundwater using date palm biochar: Application for drinking water

• High Mn and NO 3 removal attained with date palm biochar in batch and column studies • 0.1 g dosage, 1200 min contact time at pH 6 were optimum conditions in batch studies • Bed depth, influent concentration, and flow rate affected removal rates in columns • The Mn and NO 3 levels in the treated groundwater met drinking water standards This study investigates the removal of manganese and nitrate from aqueous systems in batch and column studies using date palm waste-derived biochar. High removal efficiencies and adsorption capacities (73.20%, q e : 3.57 mg/g for manganese and 94.94%, q e : 4.18 mg/g for nitrate) were attained at pH 6 with a dosage of 0.1 g biochar derived from a 50/50% mixture of date palm leaves and fronds pyrolyzed at 500°C. The equilibrium data fits well to the Freundlich and Langmuir isotherm models for manganese and nitrate respectively with R 2 =1. The Freundlich model dictates that the biochar's surface is heterogeneous, and manganese adsorption can occur in multiple layers. According to the Langmuir model, nitrate adsorption takes place on a homogeneous layer, and no interactions are fostered between the nitrate molecules on the adsorbent layer. The pseudo-second order model was found most suitable for both manganese and nitrate with R 2 = 0.99 and 1, respectively. Results from the dynamic column study showed that increasing biochar bed depth and lowering the flow rate and influent concentration increased the removal efficiencies and adsorption capacities to 53.78 (q e : 8.54 mg/g) and 45.40% (q e : 4.39 mg/g) for manganese and nitrate, respectively. To confirm the adsorption of manganese and nitrate onto the biochar, physical and chemical characterization methods were used. The optimum conditions obtained from the dynamic column study were employed to study biochar efficiency to remove manganese and nitrate from synthetic groundwater in the presence of other cations and anions as field column study. The manganese and nitrate concentrations in the treated groundwater met World Health Organization drinking water standards.

Antimicrobial finishing of cotton fabric by atmospheric pressure plasma

In order to synthesize the antimicrobial cotton fabrics, two antimicrobial agents, 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (TX-DF) and 3-(acrylamidopropyl) trimethylammonium chloride (APTAC), were grafted onto cotton fabrics by atmospheric pressure plasma treatment. Orthogonal array testing strategy (OATS) was applied to investigate the optimum treatment conditions of the atmospheric pressure plasma, including sputter-gas species, gas pressure, treatment power and time. The obtained cotton fabrics were characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDS). And the results revealed the successful grafting of two antimicrobial agents on cotton fabrics. The antimicrobial efficiency of the plasma treated cotton fabric were studied and found that the TX-DF-treated cotton fabric inactivated 99.85% S. aureus and 99.07% E. coli O157:H7 in 30 min contact time. The cotton sample grafted with APTAC inactivated 74.6% S. aureus and 92.3% E. coli O157:H7 in 30 min. The hand feeling of the plasma treated antimicrobial cotton fabrics ware measured by PhabrOmeter system, and the result showed that the plasma treatment has little effect on hand value. Thus, the antimicrobial property of cotton fabric finished with TX-DF by the argon/oxygen-plasma techniques achieved sound effects.

Adsorption of heavy metals from the aqueous solution using activated biomass from Ulva flexuosa

The removal of various highly toxic heavy metals from wastewater environment is an important task to improve environment. The biosorption potential of cadmium, cobalt and zinc was evaluated using Ulva flexuosa biomass. The impacts of adsorbent dosage, pH of the medium, contact time, and agitation speed were analyzed. The maximum biosorption potential was reached at pH 4.0, 0.4 g initial biosorbent dosage, contact time 40 min and 30 mg/L initial metal concentration for cadmium, while the other factors were similar to zinc, except 35 min contact time (p < 0.01). The optimum absorption was pH 4, 0.6% adsorbent dosage, after 30 min contact time with the heavy metals and 40 mg/L cobalt concentration. Heavy metal removal efficiency was 94.8 ± 3.3%, 87.5 ± 2.3%, and 90.8 ± 1.4%, for cadmium, cobalt, and zinc, respectively (p < 0.01). The Langmuir constant (R2) was 0.980 for cadmium, 0.838 for cobalt and it was 0.718 for zinc. The present results revealed that the selected acid modified biomass was highly suitable for the adsorption of metal ions such as, Cd2+, Co2+ and Zn2+. The present work revealed the potential application of algal biomass for the removal of various heavy metals from the environment.

Valorization of fruit waste-based biochar for arsenic removal in soils

Fruit waste disposal is a serious global problem with only 20% of such waste being routinely treated prior to discharge. Two of the most polluting fruit wastes are orange peel and walnut shell and new methods are urgently required to valorize such waste. In the present study, they where valorized via conversion into biochars at 500 °C (OPB500 for orange peel-based biochar produced at 500 °C and WaSB500 for walnut shell-based biochar produced at 500 °C), and evaluated for arsenic adsorption. A pore-rich surface morphology was observed with a low H/C ratio indicating high stability. Spectroscopic studies revealed the presence of minerals and surface functional groups (amide, carbonyl, carboxyl, and hydroxyl) suggesting high potential for arsenic immobilization. Adsorption studies revealed an arsenic removal efficiency of 88.8 ± 0.04% for WaSB500 exposed to initial arsenic concentration of 8 ppm for 5% biochar dose at 25 °C and 30 min contact time. In comparison, OPB500 showed slightly lower removal efficiency of 80.7 ± 0.1% (10 ppm initial concentration, 5% dose, 25 °C, 90 min contact time). Peak shifts in XRD and FTIR spectra together with isotherm, kinetic, and thermodynamic studies suggested arsenic sequestration was achieved via a combination of chemisorption, physisorption, ion exchange, and diffusion. The present investigation suggests valorization of fruit waste into thermo-stable biochars for sustainable arsenic remediation in dynamic soil/water systems and establishes biochar's importance for waste biomass minimization and metal (loid) removal from fertile soils.

Preparation of electrospun hybrid polyacrylonitrile nanofibers containing TiO2/Fe3O4 and their capsaicinoids adsorption applications

AbstractCapsaicinoids are a group of alkaloids responsible for the pungent and spicy flavor in chili peppers, with bioactive properties. Spray of pepper made from the active ingredient of capsicum oleoresin and other inert ingredients. In this study, polyacrylonitrile (PAN)/TiO2/Fe3O4 composite nanofiber was prepared by electrospinning method. To optimize the factors effecting diameter of membrane, Taguchi method was applied. Optimum conditions such as 9 wt% PAN, 10 wt% TiO2/Fe3O4, voltage 10 kV, and 20 cm needle tip‐to‐collector distance were selected. The specific surface area of nanofiber, 10.51 m2g‐1, was confirmed by nitrogen sorption isotherm analysis. Then, nanofiber was used as a new absorbent membrane for adsorption of capsaicinoids. After optimizing conditions using Central Composite Design (CCD), the high efficincy was obtained by 50 mg/mL nanofiber membrane, which exhibited about 96 % adsorption efficiency after 10 min contact time for 1 mg/mL of capsaicinoids. The obtained membrane could be reused for capsicinoids adsorption with high efficiency for multiply times. The results showed that the obtained nanofiber membrane has the great potential to be used in protective clothing and chemical masks to absorb the active ingredients in spray pepper.

Experimental Modeling Investigations on the Biosorption of Methyl Violet 2B Dye by the Brown Seaweed Cystoseira tamariscifolia

Methyl violet 2B dye is a major contaminant that is detrimental to both humans and aquatic microorganisms, thus it should be eliminated from water. In the current investigation, the biosorption of methyl violet 2B dye onto the brown seaweed Cystoseira tamariscifolia biomass as a sustainable low-cost biosorbent was examined by varying biosorption parameters. Biomass dosage of 7 g/L, pH 6, a temperature of 45 °C, a 60 min contact time, and a 30 mg/L initial dye concentration were determined to be the optimum biosorption conditions. Data obtained were interpreted by thermodynamic, isothermal, and kinetic models. The thermodynamic studies demonstrated that the process of dye biosorption was random and endothermic. The data were best described by Langmuir, Dubinin–Radushkevich, and Temkin models. According to the Langmuir equation, the maximal biosorption capacity (qmax) was 10.0 mg/g. Moreover, the pseudo-second-order mechanism is dominant, and chemical biosorption might represent the rate-controlling stage in the biosorption process. However, intraparticle diffusion revealed a boundary layer effect. A scanning electron microscope, energy-dispersive X-ray spectroscopy, the point of zero charge, and Fourier Transform Infra-Red were applied to characterize the algal biomass, exhibiting its remarkable structural properties and the availability of several functional groups. Additionally, ion exchange, electrostatic force, and hydrogen bonding formation are all proposed as biosorption mechanisms. As a result, C. tamariscifolia was evaluated to be a sustainable biosorbent for dye biosorption from aqueous solutions.

Green synthesized hydroxyapatite nanoadsorbent for the adsorptive removal of AB113 dye for environmental applications

The present work reports the synthesis of hydroxyapatite (HAp) via the green chemistry approach by using the leaf extract of copper pod tree and its adsorptive potential to remove Acid blue 113 (AB113) dye. FESEM-EDS characterization of the synthesized HAp confirmed rod-shaped HAp with prominent Ca and P elements. The crystallinity of HAp was ascertained by XRD and thermal stability was analyzed by TGA. The colloidal suspension stability was determined as − 17.7 mV by Zeta potential analyzer. The mesoporous structure was affirmed via BET studies with a high magnitude of specific surface area. TEM studies substantiated the rod-shaped HAp as observed in FESEM. The signals specific to HAp were observed in XPS studies. Adsorption of AB113 on the synthesized HAp was examined by varying the process parameters. Batch experiments resulted in an optimum dye removal of 92.72% at a pH of 8, 1 g/L of CP-HAp nps dosage, 20 ppm AB113 concentration, 120 min contact time, 150 rpm agitation speed and at room temperature. The maximum adsorption capacity reached 120.48 mg/g. Multifarious isotherms characterized the adsorption with Freundlich isotherm (R2 > 0.968) dominating Langmuir indicating multilayer adsorption. The experimental data reasonably matched pseudo-second-order kinetics with R2 exceeding 0.99. Thermodynamic investigations underlined the spontaneity and exothermicity of the processes. Results showed the suitability of the HAp nanoadsorbent to remove AB113 from wastestreams.

Echinops kebericho Aqueous Root Extract Assisted Green Synthesis of Zinc Oxide Nanoparticles for Photocatalytic Degradation of Methylene Blue

Wastewater treatment from industrial effluents is a global problem. Searching for environmentally safe and green technology is in the utmost interest of the scientific community. Especially organic pollutants, due to their difficulty to biodegrade, have posed a problem to human health and the aquatic environment. Hence, we reported plant extract-mediated synthesis of zinc oxide nanoparticles (ZnO NPs) in this study for photocatalytic degradation of methylene blue (MB) under sunlight irradiation. Echinops kebericho root extract was used as a reducing and stabilizing agent during the synthesis of ZnO NPs. The presence of phenolics, tannins, flavonoids, terpenoids, and alkaloids was qualitatively confirmed in the aqueous root extract of the plant under study. These secondary metabolites have a high potential in facilitating capping and stabilizing effects on the formation of ZnO nanostructures. Powder X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize the crystal structure and chemical bond of ZnO NPs, respectively. The XRD patterns showed the formation of pure phase hexagonal wurtzite ZnO NPs with an average crystal size of 14.67 nm. The photocatalytic degradation efficiency of ZnO NPs (80 mg) to remove 10 mg/L of MB dye was found to be 92.2% at pH=10 and 120 min contact time under direct sunlight irradiation. Therefore, ZnO NPs synthesized using E.kebericho were potential photocatalysts for the degradation of MB from wastewater for at least three cycles.

Potential efficiency of magnetic mesoporous silica nanoparticles modified with aspartic acid to cationic dye removal from aqueous solution

ABSTRACT This work includes the preparation of Fe3O4 NPs coated with mesoporous silica nanoparticles (MSNs). The combination between two different materials could improve the removal efficiency of pollutants from wastewater. The surface modification of magnetic nanoparticles could reduce the agglomeration. The Fe3O4-MSNs surface was modified with aspartic acid liked with the adsorbent surface via hydrophobic linker (1,4-phenylene diisothiocyanate, PDITC) to effectively remove the methylene blue (MB) dye from the contaminated water. The particles size was ranged between 110 and 160 nm, as estimated by SEM and TEM. The surface zeta potential of the surface was found to be negatively at pH above 2.5. The nanosorbent efficiency was evaluated at different conditions such as pH, contact time and initial MB concentration. The maximum adsorbed amount of the MB was estimated to be 135 mg/g at 200 mg/L MB concentration and 80 min contact time. The adsorption isotherm fits with the Langmuir model and pseudo-second-order kinetics.

Sustainable Microbial and Heavy Metal Reduction in Water Purification Systems Based on PVA/IC Nanofiber Membrane Doped with PANI/GO

Effective and efficient removal of both heavy metal pollutants and bacterial contamination from fresh water is an open issue, especially in developing countries. In this work, a novel eco-friendly functional composite for water treatment application was investigated. The composite consisted of electrospun nanofiber membrane from blended polyvinyl alcohol (PVA)/iota carrageenan (IC) polymers doped with equal concentrations of graphene oxide (GO) nanoparticles and polyaniline (PANI). The effectiveness of this composite as a water purification fixed-bed filter was optimized in a batch system for the removal of cadmium (Cd+2) and lead (Pb+2) ions, and additionally characterized for its antimicrobial and antifungal properties and cytotoxicity effect. The fiber nanocomposite exhibited efficient antibacterial activity, with maximum adsorption capacity of about 459 mg g−1 after 120 min for Cd+2 and of about 486 mg g−1 after 90 min for Pb+2. The optimized conditions for removal of both metals were assessed by using a response surface methodology model. The resulting scores at 25 °C were 91.4% (Cd+2) removal at 117 min contact time for 89.5 mg L−1 of initial concentration and 29.6 cm2 membrane area, and 97.19% (Pb+2) removal at contact time 105 min for 83.2 mg L−1 of initial concentration and 30.9 cm2 nanofiber composite membrane. Adsorption kinetics and isotherm followed a pseudo-second-order model and Langmuir and Freundlich isotherm model, respectively. The prepared membrane appears to be promising for possible use in domestic water purification systems.

Sustainable Management Strategy for Solidification/Stabilization of Zinc Plant Residues (ZPR) by Fly Ash/Clay-Based Geopolymers

Solidification/stabilization (S/S) of acid waste using Ordinary Portland Cement (OPC) is widely implemented, but, due to the impact on climate change, alternative methods are being investigated. In this work, first, the feasibility of using coal fly-ash/clay-based geopolymers for the S/S of Zn plant residues (ZPR), Cadmium Sponge (CS), and Anode Mud (AM) is proposed as a treatment prior to disposal in landfills. Different variables, such as the type of processing, molding (as-received waste), and pressing (dried waste), and activators, a commercial and an alternative residual sodium carbonate, have been studied. The technical and environmental assessments of the S/S process by means of compressive strength and the leaching of critical pollutants have been monitored. Immobilization efficiencies of Cd and Zn higher than 99% have been obtained by dosing 50% of the acid waste, 6 M NaOH solution (20 min contact time), cured at 75 °C (48 h) and at room temperature (28 days), achieving in the leachates pH values of 7 to 10 and [Cd] and [Zn] &lt; 1 and 2.5 mg/kg, respectively. However, alkaline activation increases As leaching, mainly associated with the clay. Secondly, removing clay from the geopolymer formulation, the optimization of geopolymer parameters, acid waste/geopolymer ratio, liquid/solid ratio, and NaOH molar concentration enables obtaining a significant reduction in the release of As and Cd, and Zn is kept at acceptable values that meet the non-hazardous waste landfill disposal limits for the S/S of both acid wastes.

Photocatalytic removal of toxic dyes, liquorice and tetracycline wastewaters by a mesoporous photocatalyst under irradiation of different lamps and sunlight

Simple recyclable K5CoW12O40/TiO2 was synthesized and used to remove methyl orange, rhodamine B, direct red 16 and crystal violet toxic organic dyes, liquorice industrial wastewater and tetracycline (TC) as an antibiotic. Photoactivity of the catalyst was checked out under irradiation of various lamps (such as 18 W fluorescent, 300 W Xenon, LED and IR lamps). The best efficiency was obtained by fluorescent lamp at catalyst loading of 3 g/L, initial pH of 5, initial dye concentration of 5 ppm, complete degradation was achieved after 30 min contact time. Mechanistic investigation showed that·O2 radicals and h+ are majorly responsible for photodegradation in this process. Electrochemical investigation, Nyquist, Bode, Mott-Schottky, Tauc plots and photoluminescence proved that using this photocatalyst delay the electron-hole recombination, increase the lifetime of excited electron, extend light absorption to visible region and improve the light absorption capacity. This photocatalyst work well under winter sunlight. Also 97% and 84% dye removal was obtained for liquorice with 300 and 1000 COD at optimal condition. This catalyst showed similar activity for TC wastewater. Photocatalyst was characterized by FE-SEM, EDX, AFM, FT-IR, XRD, PL, DRS, EIS, BJH and BET.

Leaching of Ibute-Nze kaolin iron-oxide impurity with oxalic acid process optimization of dissolution conditions using response surface methodology

The goal of this research was to remove iron oxide from Ibute-Nze kaolin by dissolving the clay mineral in an aqueous oxalic acid solution and optimizing the process. The chemical composition of the raw and modified clay was determined using x-ray fluorescence, and the morphology of the solid sample was determined using a scanning electron microscope. The best conditions for the oxalic acid leaching of iron-oxides impurity from Ibute-Nze kaolin were determined using response surface methodology based on Box-Behnken design. The studies were carried out within the following process parameter ranges: 40–90 leaching temperature; 0.075-0.355mm particle size; 1–6 mol/dm3 acid concentration; 0.02–0.12 g/cm3 kaolin sample to acid ratio and 30-240 min contact time. The characterization revealed that Ibute-Nze clay is kaolinitic in nature and calcination at 750 opens more pores for its leaching. According to the analysis of variance, a second-order polynomial regression equation provided the best fitting for the experimental data. The predicted and experimental response values were shown to be correlated (R2 = 0.9276) in the experimental runs. The following were found to be the best conditions for the leaching process variables: 83.2051 leaching temperature, 0.0827mm particle size, 3.6179mol/dm3 acid concentration; 0.0287g/cm3 kaolin to acid ratio and 217.932min reaction time. The chemical leaching process was 92.6035 per cent under these conditions, which made the clay good for industrial applications.

From waste to waste: iron blast furnace slag for heavy metal ions removal from aqueous system

Inordinate levels of heavy metals in water sources have long been a matter of concern, posing serious environmental and public health risks. Adsorption, on the other hand, is a viable technique for removing heavy metals from water due to its high efficiency, low cost, and ease of operation. Blast furnace slag (BFS) is considered a cheap sorbent for the get rid of Co2+ and Pb2+ ions from aqueous media. The nonmodified slag is characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption–desorption isotherms, energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), and zeta potential. The removal of Co2+ and Pb2+ ions was carried out using batch adsorption experiments from an aqueous medium. The influence of several variables as pH, contact time, adsorbent dose, temperature, and initial ions concentration was considered. The isotherm, kinetic, thermodynamic, and recyclability were also conducted. The maximum uptake capacity for Co2+ and Pb2+ was 43.8 and 30.2 mg g−1 achieved at pH 6 after 60 min contact time. The adsorption kinetics and isotherms of BFS for Co2+ and Pb2+ fitted well to Avrami and Freundlich models, respectively. The main adsorption mechanism between BFS and the metal ions was ion exchange. The regeneration of the used slag was studied for reuse many cycles. In terms of economics and scalability, nonmodified BFS treatment has great potential as a cost-effective adsorbent that could be used in water pollution treatment.Graphical abstract

Lignin from Agro-Industrial Waste to an Efficient Magnetic Adsorbent for Hazardous Crystal Violet Removal.

The presence of cationic dyes, even in a tiny amount, is harmful to aquatic life and pollutes the environment. Therefore, it is essential to remove these hazardous dyes to protect the life of marine creatures from these pollutants. In this research, crystal violet (CV) dye elimination was performed using a lignin copper ferrite (LCF) adsorbent. The adsorbent was synthesized and characterized using FTIR, Raman, SEM, EDX with mapping, and VSM, which proved the successful formation of magnetic LCF. Adsorption experiments were performed using different effective parameters. The highest adsorption potential (97%) was executed at mild operating conditions, with a 5 min contact time at room temperature and pH 8. The adsorption kinetic study utilized four kinetic models: first-order, second-order, intraparticle diffusion, and Elovich. The results revealed that the adsorption process complies with the pseudo-first-order with a maximum adsorption capacity of 34.129 mg/g, proving that the adsorption process mechanism is a physical adsorption process. Three isotherm models, Langmuir, Freundlich, and Temkin, were examined. The adsorption mechanism of CV onto LCF was also followed by the Langmuir and Freundlich models. The thermodynamic parameters were examined and revealed that the adsorption onto LCF was an exothermic process. It was proposed that the adsorption process is a spontaneous exothermic process. LCF appears to forcefully remove toxic CV dye from textile wastewater.