Batch Experimental Method Research Articles

Effective Chromium (VI) Removal from Contaminated Water by Chemically Modified Litchi Chinensis Seed Powder: Characterization, Kinetic and Isotherm Studies

In this work, Litchi chinensis seed powder has been chemically modified to charred Litchi chinensis seed powder (CLCS) for removal of Cr(VI) from the simulated wastewater. The adsorption capacity of CLCS for Cr(VI) was determined in batch experiment method. The materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared (FTIR) spectroscopy. Biosorption behaviour was investigated using isotherm and kinetic models. CLCS demonstrated a noteworthy adsorption capacity for Cr(VI), with a maximum adsorption capacity of 69.93 mg/g at pH 2.0. The Cr(VI) adsorption onto CLCS was found to follow pseudo-second-order kinetics and the experimental data best fitted with Langmuir isotherm model. According to the results, Cr(VI) can be removed from acidic wastewater using CLCS as an adsorbent. The results indicate that further studies and modification are necessary to improve the efficiency of the CLCS, and its feasibility at normal pH conditions.

Facile synthesis of Zn/Co LDH for the removal of oxytetracycline from wastewater: Experimental and DFT-Based analysis

Zn/Co layer double hydroxide (LDH) was first time synthesized for the removal of oxytetracycline (OTC) from aqueous solution. It was characterization by XRD, FTIR, BET, and SEM. The adsorption capacity of Zn/Co LDH for OTC was investigated by batch experimental method at different parameters and adsorption capacity was significantly enhanced to 387.59 mg.g−1 at pH = 8 and T = 15 °C. The kinetic and isothermal studies were performed at the best-selected pH and temperature with the help of different models. The adsorption kinetics plots were consistent with the pseudo-second-order model (R2 = 0.9935), indicating chemical adsorption through electrostatic interactions. The adsorption isotherm curves were more accorded with the Langmuir model as compared to the Freundlich model (R2 = 0.9986) indicating the monolayer mechanism of adsorption. The adsorption mechanism was well explained by DFT studies. The study suggests Zn/Co LDH has great potential for the removal of OTC at a large scale for wastewater treatment.

Removal of uranium (VI) ion from aqueous solution using kaolinite

In this study, the adsorption of uranyl ion (UO22+) onto kaolinite mineral from its aqueous solutions has been investigated using the batch experiment method under different parameters. Uranyl ions were measured spectrophotometrically using 8-hydroxy quinoline as a chromogen. The effect of contact time, pH, initial ion concentration, adsorbent amount, and ionic strength has been designated to establish this study. The adsorbed percentage increased dramatically as the pH increased from 1 to 5; from 28% to 70% at well-known parameters of contact time, pH value, adsorbent amount, and initial ion concentration. Above pH 5, the adsorption affinity was virtually unchanged. On the other hand, the adsorbed percentage decreased from 68% to 57% when the initial uranyl ion concentration increased from 90 to 120 ​mg/L. The overall results showed that the maximum uranyl ion adsorption percentage reached at the initial concentration of 90 ​ppm, pH 4.5, contact time of 5 ​h, and an adsorbent dosage of 4.0 ​g/L. The adsorption behavior of the uranium ion on kaolinite obeys Langmuir (1918) and Freundlich isotherm models, with R2 value above 0.998 for both.

Biosorption of Fe (II) and Pb (II) on unmodified Senna tora: Isotherm and kinetic modeling

Contamination of environment by heavy metals has become a major concern worldwide. The role of conventional methods in remediating heavy metals has become ineffective and costly. Therefore, it becomes imperative to explore bioremediation using a cost effective, efficient and environmentally friendly alternative method of removing heavy metals. In this study, the adsorption behaviour of Senna tora, a low-cost adsorbents, with respect to Fe(II) and Pb(II) ions, has been studied in order to consider its application to the treatment of wastewater. The physicochemical properties of the unmodified Senna tora were predetermined. The batch experimental method was employed: parameters such as pH, contact time, dosage and initial metal concentration were studied. The influence of the pH of the metal ion solutions on the uptake levels of the metal ions by the adsorbent used was carried out between pH 4 and 10. The optimum pH for both Fe (II) and Pb(II) removals by Senna tora was 7. An equilibrium contact time of 60 min was required for the adsorption of Pb(II) ions onto Senna tora. Percentage sorption of Fe(II) increased from 94 to 99% and that of Pb (II) from 94.4 to 96% as adsorbent dose was increased from 2 to 10 g. The isotherms data provide information on the capacity of the adsorbent or the amount required to remove a unit mass of pollutant under the operating conditions. The equilibrium data of Fe(II) and Pb(II) adsorbed onto Senna tora pods were fitted by the Langmuir, Freundlich, and Temkin isotherms. On the basis of correlation coefficients R2, it is concluded that the Fe(II) and Pb(II) biosorption is better fitted to the Freundlich model. This suggests that the biosorption of Fe(II) and Pb(II) on the surface of Senna tora pods occurs on heterogeneous binding sites with equivalent adsorption energies and multilayer coverage. The results demonstrated that Senna tora pod holds potential to remove cationic heavy metal species from industrial wastewater.

Physicochemical Properties and Application of Silica-Doped Biochar Composites as Efficient Sorbents of Copper from Tap Water.

This article concerns research on new sorption materials based on silica-doped activated carbon. A two-stage synthesis involved pyrolysis of plant material impregnated in a water glass solution, followed by hydrothermal activation of the pyrolysate in KOH solution. The resulting composite can be used as a sorbent in drinking water filters. The proposed method of synthesis enables the design of materials with a surface area of approximately 150 m2·g-1, whose chemical composition and structure were confirmed by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA) and Fourier-transform infrared spectroscopy (FTIR). The sorption properties of the obtained materials were determined relative to copper ions using the batch experiment method. The optimal operating parameters of the obtained materials relative to copper ions are T = 313.15 K, pH = 5, S:L ratio = 4 g·dm-3 and t = 120 min. The research shows that the sorption kinetics of copper ions can be described by a pseudo-second-order model. The plotted copper(II) sorption isotherm clearly indicates the Langmuir model. Under optimal conditions, the maximum sorption of copper ions was 37.74 mg·g-1, which is a satisfactory result and confirms the possibility of using the obtained material in drinking water filters.

Recyclable magnetic nanocomposites for efficient removal of cadmium ions from water: performance, mechanism and isotherm studies

ABSTRACT Herein, succinic acid functionalized Fe3O4@AMPA nanocomposite was synthesized as an effective adsorbent and used for the efficient removal of Cd(II) ions from aqueous media. Zeta potential, BET, TEM, TGA, and FTIR spectra were applied to characterize the Fe3O4@AMPA@SA nanocomposite. According to the BET analysis, the surface area of Fe3O4@AMPA@SA was found to be 43 m2/g. The influence of pH value, initial Cd(II) concentration, adsorbent dosage, temperature, and contact time on the adsorption process was achieved via the batch experiment method. The result showed that the optimal parameters were 6, 250 mg/L, 0.03 g/50 mL, 150 min, and 25°C, respectively. The experimental data fitted well to the Langmuir isotherm and the pseudo-first-order models. The maximum monolayer adsorption capacity of Cd(II) ions was 265 mg g−1. The adsorption mechanism of Cd(II) on magnetic nanocomposite is physical adsorption. The Fe3O4@AMPA@SA nanocomposite shows excellent reusability with a removal efficiency of 81.4% after three cycles.

STUDI KOMPARASI ADSORPSI TIGA JENIS ZAT WARNA REMAZOL PADA PERMUKAAN KARBON AKTIF

Remazol is a reactive dye that is widely used in the textile industry with functional groups that can be well covalently bonded to textile fibres, but difficult to decompose, carcinogenic, and harmful to the health and ecosystems. This study specifically aims to analyse the adsorption power of activated carbon on three types of Remazol dyes using batch experiment method as an effective way to reduce the concentration of these dyes in textile industry wastewater. Using activated carbon with the same treatment, Remazol Red dye had the best interaction and was adsorbed in the highest amount on the activated carbon surface (125.16 mg/g), followed by Remazol Blue (16.23 mg/g) and finally Remazol Black dye (11.07 mg/g). The three adsorption processes that occur are in accordance with the Langmuir adsorption isotherm model, with color removal percentage of 74.4 % (Remazol Red), 49.5 % (Remazol Blue), and 48.1 % (Remazol Black). These results are in accordance with the structural studies conducted on the three types of Remazol synthetic dyes, in which Remazol Black with the bulkiest structure has the weakest physical interaction with carbon atoms on the activated carbon surface thus absorbed in the least amount on the adsorbent surface.

Development of Cerium Oxide/Corncob Nanocomposite: A Cost-Effective and Eco-Friendly Adsorbent for the Removal of Heavy Metals.

This research aims to assess the efficiency of the synthesized corncob as a cost-effective and eco-friendly adsorbent for the removal of heavy metals. Therefore, to carry out the intended research project, initially, the corncob was doped with nanoparticles to increase its efficiency or adsorption capacity. The prepared adsorbent was evaluated for the adsorption of cadmium (Cd) and chromium (Cr) from aqueous media with the batch experiment method. Factors that affect the adsorption process are pH, initial concentration, contact time and adsorbent dose. The analysis of Cd and Cr was performed by using atomic absorption spectrometry (AAS), while the characterization of the adsorbent was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that there is a significant difference before and after corncob activation and doping with CeO2 nanoparticles. The maximum removal for both Cd and Cr was at a basic pH with a contact time of 60 min at 120 rpm, which is 95% for Cd and 88% for Cr, respectively. To analyze the experimental data, a pseudo-first-order kinetic model, pseudo-second-order kinetic model, and intra-particle diffusion model were used. The kinetic adsorption studies confirmed that the experimental data were best fitted with the pseudo-second-order kinetic model (R2 = 0.989) and intra-particle diffusion model (R2 = 0.979). This work demonstrates that the cerium oxide/corncob nanocomposite is an inexpensive and environmentally friendly adsorbent for the removal of Cd and Cr from wastewater.

Thermodynamic Studies on the Sorption of Lead (II), Chromium (III) and Manganese (II) ions onto Acid-Activated Shale

Shale mineral in its raw form was collected, processed, calcinated and activated using tetraoxosulphate (VI) acid. The microstructural arrangement and chemical composition of the raw, calcinated and acid-activated shale was determined using x-ray fluorescence and scanning electron microscope to verify its ability for the removal of Pb2+, Cr3+ and Mn2+ from wastewater. Batch experimental method was used to study the effect of different adsorption parameters on the sorption efficiency of shale. The effect of temperature on the sorption of Pb2+, Cr3+ and Mn2+ on acid-activated shale was investigated at varied temperature of 15 – 40 . The calculated value of enthalpy () was 12.50 kJ/mol for Pb2+ adsorption, 5 kJ/mol for Cr3+ and 11 kJ/mol for Mn2+ adsorption. The calculated values of Gibbs free energy () varies from -6.576 kJ/mol to 1.358 kJ/mol for Pb2+ adsorptions, from -2.696 kJ/mol to 0.192 kJ/mol for Cr3+ adsorptions, and -4.994 kJ/mol to 1.870 kJ/mol for Mn2+ adsorptions. The entropy () range is 38.68 – 60.946 kJ/mol for Pb2+ adsorptions, 16.69 – 24.58 kJ/mol for Cr3+ adsorptions, and 31.70 – 51.10 kJ/mol for Mn2+ adsorptions. The positive value of shows that the adsorption of Pb2+, Cr3+ and Mn2+ onto acid-activated shale was an endothermic process. The values of are negative at temperature of 298 K and above for the three metal ions studied, which confirmed that the adsorption of Pb2+, Cr3+ and Mn2+ on acid-activated shale was a spontaneous process. The decline in with increasing adsorption temperature showed that adsorptions of Pb2+, Cr3+ and Mn2+ onto acid-activated shale became better at higher temperature while the positive value of for all metal ions studied showed the amplified arbitrariness at the solid-solution interface during the fixation of the adsorbate on the active site of acid-activated shale.

Application of graphene‐based adsorbents in the treatment of dye‐contaminated wastewater; kinetic and isotherm studies

AbstractThe adsorption of methylene blue (MB) on graphene‐based adsorbents was tested through the batch experimental method. Two types of graphene‐based adsorbents as graphene oxide (GO) and reduced graphene oxide (RGO) were compared to investigate the best adsorbent for MB removal. So that optimizing the MB removal for the selected type of graphene‐based adsorbent, the diverse experimental factors, as pH (2–10), contact time (0–1440 min), adsorbent dosage (0.5–2 g/L), and initial MB concentration (25–400 mg/L) were analyzed. The conclusions indicated that the MB removal rised with an increase in the initial concentration of the MB and so rises in the amount of adsorbent used and initial pH. Maximum dye removal was calculated as 99.11% at optimal conditions after 240 min. Adsorption data were compiled by the Langmuir isotherm (R2: 0.999) and pseudo‐second‐order kinetic models (R2: 0.999). The Langmuir isotherm model accepted that the homogeneous surface of the GO adsorbent covering with a single layer. And the adsorption energy was calculated as 9.38 kJ mol−1 according to the D‐R model indicating the chemical adsorption occurred. The results show that GO could be utilized for the treatment of dye‐contaminated aqueous solutions effectively.

Application of Mussell-derived biosorbent to remove NH4+ from aqueous solution: Equilibrium and Kinetics

Mussel shells are often considered an abundant waste with no use. This study shows that the employment of mussel shells as a biosorbent for ammonium from water environment is completely possible. By using batch experimental method, optimal conditions for the ammonium adsorption onto mussel shells were determined. Specifically, those include a pH level of 8, contact time of 90 min, an initial ammonium concentration of 40 mg/l and the adsorbent dose of 700 mg/25 ml. With such operating conditions, experiments in laboratory aqueous solutions resulted in a maximum adsorption capacity of 2.33 mg/g, corresponded by 46.575% of efficiency. Adsorption isotherms and kinetics were well described with the Freundlich isothermal model, suggesting a heterogeneous adsorption process occurring on multilayers and both the pseudo-first-order and the pseudo-second-order, implying that the operational fundament was based on chemisorption. Analyses regarding SEM, EDS and FTIR were also implemented to identify the morphology, composition and functional groups of the adsorbent.

Removal of extremely low concentration cobalt by intercalation composite material of carbon nitride/titanium dioxide

Due to the high toxicity and the great harm of radioactive cobalt to the human body and the environment, the removal of heavy metal cobalt ions from radioactive wastewater had attracted more and more scientific researchers. In this paper, the intercalation composite material of carbon nitride itanium dioxide (g-C3N4/TiO2) composite material which combined the advantages of the two materials was prepared and its actual effect of removing Co (Ⅱ) from wastewater was evaluated. Batch experimental method was employed for the investigation of the impact of solution pH during adsorption, adsorption kinetics, adsorption thermodynamics and adsorption isotherms. In this experiment, the saturation adsorption capacity of the composite material to Co (Ⅱ) was 91.55 mg/g, while the bulk g-C3N4 was only 13.2 mg/g. The adsorption kinetics showed that the adsorption process followed a pseudo-second-order kinetic model. The adsorption thermodynamic showed that the adsorption of Co (Ⅱ) was a spontaneous endothermic process. The Langmuir isotherm adsorption model was more consistent with the adsorption isotherm than the Freundlich model. The experimental results proved that g-C3N4/TiO2 composite material had a good adsorption and removal effect on extremely low concentration of Co (II) and was a promising adsorbent for removal radioactive Co (II) from nuclear industrial wastewater.

Adsorption behaviors of methylene blue onto tubular cadmium sulfide polycrystals

The temporal evolution of methylene blue’s adsorption onto tubularly mesoporous CdS synthesized by templating the fibrous precursor of cadmium oleates is investigated using the batch experiment method. UV–visible measurements on the supernatants at λ = 665 nm reveal the adsorption of methylene blue at 25 and 5 °C exhibits the type IV isotherms, having the typical features of mesoporous materials, and the isotherm can be fitted by Freundlich and Langmuir equation for low and high ce, respectively. The adsorption enthalpy change H, which is estimated − 12 kJ/mol, reveals the H-bond existing between CdS and MB molecules. The first hour of contact has proved to be a quite rapid dynamics, and subsequently, the dye molecules go through a tardy process in 30–36 h to reach the equilibrium. The uptake of methylene blue by tubular CdS is interpreted by pseudo-second-order model better than by pseudo-first-order model, and the experimental data over the whole adsorption process can be described based on the intraparticle diffusion model.

Environment responsive Al3+ networked chitosan-gelatin spherical beads for the effective removal of organic pollutants from aqueous solutions

In order to remove noxious Congo Red (CR), Acid Red 1 (AR1) and Reactive Red 2 (RR2) dye molecules from water, an environment responsive and biodegradable spherical chitosan-gelatin biopolymeric beads were designed and embedded with Al3+ ions. The surface morphology, specific surface area, crystalline phases, elemental composition and thermal properties of the CAG spherical beads had examined. Adsorption experiments were explored to investigate the adsorption properties of dye molecules on CAG spherical beads. The adsorption parameters like solution pH, contact time, co-existing ions, adsorbent dosage and regeneration studies were optimized using batch experiment method. The maximum adsorption efficiency of CR, AR1, and RR2 dye molecules on CAG spherical beads were 34.89, 32.36 and 33.63 mg/g, respectively. The adsorption system fits well with pseudo-second-order kinetics and Freundlich isotherm model. The molecular interactions followed in the adsorption mechanisms were the electrostatic force of attraction, surface complexation and hydrogen bondings that exist between dye molecules and the CAG spherical beads. The CAG spherical beads could be regenerated up to six consecutive cycles using an aqueous 0.1 M NaOH solution. The study emphasizes that the fabricated CAG spherical beads could act as a potential adsorbent in the water/wastewater treatment process.

Movement and Fate of 2,4-D in Urban Soils: A Potential Environmental Health Concern.

The fate and movement of 2,4-dichlorophenoxyacetic acid (2,4-D), in terms of sorption–desorption and leaching potential, were evaluated in urban soils following the batch experimental method. The sorption kinetics of 2,4-D in soils followed both “fast” and “slow” sorption processes that could be well described by a pseudo-second-order kinetics model, suggesting that 2,4-D was partitioned into soil organic matter and clay surfaces, and eventually diffused into soil micropores. The sorption isotherms were linear, following both Langmuir and Freundlich models. Partially decomposed or undecomposed organic matter present in urban soils decreased sorption and increased desorption of 2,4-D. Also, sorption of 2,4-D increased with an increase in the contents of clay and Al and Fe oxides, whereas sand and alkaline pH increased the desorption process. The lower calculated Kd values suggest that 2,4-D is highly mobile in urban soils than in agricultural soils. The calculated values of groundwater ubiquity score, leachability index, and hysteresis index indicated that the herbicide is highly prone to leach out from surface soil to groundwater which might affect the quality of potable water. The present study clearly suggests that 2,4-D must be judiciously applied in the urban areas in order to minimize the potential health and environmental risks.

Remediation of industrial dye by Fenton-activated biogenic waste

This research work gave details on the application of Malacantha alnifolia tree bark as a low-cost adsorbent and a heterogeneous Fenton-catalyst for the removal of methylene blue from aqueous solution. The tree bark was modified using different ratios of ferrous sulphate and hydrogen peroxide (Fenton's reagent). Fenton modification of the adsorbent was more effective at lower concentration of ferrous sulphate solution (100 mg.L − 1) and at higher concentration of hydrogen peroxide solution (60,000 mg.L − 1). The modified adsorbent was characterised by x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) and pH of point of zero charge (pHpzc). Applying batch experimental method, the effects of various parameters such as pH, Fe2+/H2O2 concentration ratio, contact time, initial methylene blue (adsorbate) concentration and adsorbent dose were studied. The experimental data were best described by Freundlich isotherm model (R2=0.972) and the adsorption kinetics followed the pseudo-second order kinetic model (R2=1.000). The thermodynamic analysis of the adsorption processes indicated a spontaneous adsorption process (ΔG° at 25 °C= –5.335 kJ/mol); change in enthalpy showed that the remediation process was exothermic (ΔH°= –1.964 kJ/mol) and change in entropy indicated that the adsorption process was disorderly (ΔS°=+11.314 J/mol/K). Desorption studies showed that the modified adsorbent can be regenerated effectively and re-used. Fenton-modification improved the adsorption capacity of Malacantha alnifolia tree bark and prevented bleeding of the tree bark into the dye solution.

Sodium Salt of the Maleic Acid-Decene-1-Styrene Terpolymer as a Sorbent for Removal of Copper Ions from Water Solution

The study is aimed at investigating the efficiency of the sodium salt of maleic acid-decene-1-styrene terpolymer as a sorbent for the removal of copper ions from aqueous solution. The removal of copper ions on synthesized polymer-sorbent was carried out using a batch experiment method. Sorption of copper ions was studied at different values of the contact time, sorbent dosage, pH and initial concentrations of copper ions. The obtained results have been analyzed in Langmuir, Freundlich, and Dubinin—Radushkevich adsorption models. The equilibrium experimentally measured sorption capacity of the sorbent is 0.512 g·g−1. The calculated value of the maximum experimental sorption capacity from the Langmuir and Freundlich equations is equal to 0.754 and 0.725 g·g−1, respectively. The value of (1/n) in Freundlich equation is between 0 and 1, which indicates that the sorption process is governed by chemisorption. The value of the mean sorption energy calculated from Dubinin—Radushkevich equation also confirms that the sorption of copper ions by synthesized polymer salt has chemical character.

ADSORPTIVE REMOVAL OF PHOSPHATE ONTO IRON LOADED LITCHI CHINENSIS SEED WASTE

Raw and charred Fe(III)-loaded Litchi chinensis seed waste (FeRLW and FeCLW) as bio-adsorbents was investigated to remove phosphate from aqueous solution. Various physico-chemical parameters such as equilibrium time, pH and adsorbent dosage were studied by batch experiment method. The maximum adsorption capacities for phosphate removal by FeRLW and FeCLW were found to be 96.5 mg/g and 100 mg/g, respectively. The experimental results revealed that biomaterials of FeRLW and FeCLW can be used as effective and economically viable adsorbents for the removal of phosphate from waste water.

Casuarina equisetifolia cone as sustainable adsorbent for removal of Malachite green dye from aqueous solution using batch experiment method

Various methods have been devised in order to treat the wastewaters before they are disposed into water bodies such as the rivers and the seas. One of the methods used is adsorption as it has the advantages of cheap, environmentally friendly and wide range of materials can be used. In this study Casuarina equisetifolia cone (CEC) was used to remove malachite green (MG) from aqueous solution and the adsorption process was investigated through contact time, pH, temperature, ionic strength and dye concentration. The experimental results indicated that CEC can operate well in high ionic strength solution and was not significantly affected by temperature. The adsorption process followed the pseudo-2 nd order and can be described using the Langmuir model where the maximum adsorption capacity was determined as 58 mg g -1 .

Influence of inherent iron and oxygen concentrations on selenite sorption process using bentonite

The oxygen concentration and inherent Fe in bentonite have a significant influence on the Se(IV) sorption process. In this study, the sorption of selenite on natural bentonite was investigated using a batch experiment method, and the distribution coefficient ( K d) values were obtained in the pH range from 2.0 to 10.0 under oxic/anoxic conditions. The K d values always reached a maximum value at a pH of 4 under oxic conditions and at a pH of 8 under anoxic conditions; meanwhile, the K d value under anoxic conditions was larger than the value under oxic conditions, especially in regard to the maximum K d values. The oxygen conditions have a significant influence on the ratio of redox-sensitive Fe2+/Fe3+, which was closely related to the difference in the K d values under both oxic/anoxic conditions. Ferric selenite and green rust could be responsible for the maximum K d values under oxic/anoxic conditions. In the leaching experiments, we found that the Fe2+ in bentonite could replace Mg2+ and Al3+ in the octahedral sheet. Spectroscopy methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) were used to characterize the surface properties of the samples after reaction. Overall, this study shows that the addition of Fe2+-containing materials into backfill/buffer materials under anoxic condition could enhance the sorption of 79Se(IV).