Pseudo-second Order Reaction Model Research Articles

Reductive sequestration of Cr (VI) by phosphorylated nanoscale zerovalent iron

The cracked phosphorylated nanoscale zerovalent iron (p-nZVI) has a strong electron selectivity towards the reductive removal of many heavy metal ions in waters. However, the unintended environmental risk after interactions with impurities or wastewater are not involved. Therefore, in this study, the phosphate group was successfully adsorbed into p-nZVI, and the cracked p-nZVI was successfully prepared with an optimal P/Fe ratio of 0.5%. The dosages of p-nZVI and temperatures were positively correlated with the removal rates. The removal process of Cr(VI) was more suitable by the Langmuir isothermal model（R2 > 0.99). The process of Cr (VI) (10, 20 and 40 mg/L) removal more fitted the pseudo first-order reaction model, while the process of Cr (VI) (60, 80 mg/L) removal more fitted the pseudo second-order reaction model. The Cr (VI) removal rates gradually decreased when the pH was increased. Dissolved oxygen slowed nanoiron reaction rates. The order of inhibition on the reactivity towards Cr(VI) was SiO32− > SO42− > PO43− > NO3− > HCO3−.The facilitation followed the order of Cd2+>Cu2+>Mg2+>Mn2+>Ca2+. Ca2+ showed an inhibitory effect, but all other cations showed different degrees of facilitation. The promotion effect is relatively similar in presence of Mn2+ or Mg2+. HA had a significant inhibitory effect. Environmental friendly p-nZVI had a good effect in simulated groundwater, seawater, river water and secondary effluent of the urban sewage treatment plant. The main pathway to remove Cr (VI) was in situ reduction by p-nZVI. The improved adsorption and reduction effect of p-nZVI on heavy metal ions in water was due to the structural change and the phosphate group.

THE STUDY OF HEAVY METAL ION SORPTION KINETICS

Phosphorus-containing polymeric sorbent based on butadiene-styrene rubber was used to remove zinc, iron and chromium ions from water. The research was carried out to study the sorption characteristics by determining the effects of various parameters, such as the pH of the solution, the initial concentration of metal ions, the sorbent mass, the phase contact time, and temperature. The regularities of the kinetics of the sorption of zinc, iron and chromium ions on the phosphorus-containing sorbent synthesized on the basis of butadiene-styrene rubber were studied. On the basis of the results it was defined that the process of sorption of zinc, iron and chromium ions on the cation exchanger proceeds by an ion-exchange mechanism. The kinetics of this process is a combination of external and internal diffusion kinetics (with some predominance of external diffusion kinetics) and is better described by the pseudo-second order reaction model. In addition, a certain contribution to the overall speed of the process is made by the interaction of the sorbed ions with the functional groups of the cation exchanger. Keywords: phosphorus-containing cation exchanger, zinc, iron, chromium, sorption, kinetics.

Synthesis of functional hydrochar from olive waste for simultaneous removal of azo and non-azo dyes from water

Industrial wastewater effluent containing dyes and hazardous waste, such as olive waste, pose serious threat to health and environment. This work investigated the removal of azo and non-azo dyes from a single and binary aqueous system using hydrochar produced from hazardous olive waste using hydrothermal carbonization (HTC). Optimisation suggested hydrochar obtained at 250°C (HC-9) exhibited best physiochemical, structural properties and around 300% increase in carboxylic and carbonyl groups indicated by nuclear magnetic resonance spectroscopy. HC-9 removed ∼100% of Methylene blue and Congo red in single (120 and 180 min) and binary system (60 min), respectively. Ex situ X-ray photon electron spectroscopy and surface area analysis after adsorption suggested chemisorption supported by pseudo-second order reaction, Langmuir, and Redlich-Peterson model. HC-9 exhibited around 80% reusability in three adsorption cycles. Thus, better working efficiency of our hydrochar in the complex wastewater make it a potential candidate to be employed in commercial plants.

Synthesis and characterization of γ-cyclodextrin-graphene oxide nanocomposite: Sorption, kinetics, thermodynamics and simulation studies of tetracycline and chlortetracycline antibiotics removal in water

γ-Cyclodextrin-graphene oxide nanocomposite was synthesized and characterized for sorption, kinetics, thermodynamics, and simulation studies of tetracycline and chlortetracycline antibiotics removal from water. The optimized sorption parameters were 400 mg/L concentration, 30 min contact time, pH 8.0, dose 1.0 g/L and 25 °C temperature. The sorption followed Langmuir, Temkin, and D-Rs models. The maximum removals of tetracycline and chlortetracycline were 91.25 and 93.75% respectively, with a variation of percentage removal at different pHs ranges [355.0 (88.75%), 360.0 (90.0%) and 365.0 mg/g (91.25%) for tetracycline and 365.0 (91.25%), 370.0 (92.5%) and 375.0 mg/g (93.75%) chlortetracycline]. The sorption followed pseudo-second kinetic order reaction and liquid film diffusion kinetic model. The positive values of entropy (12.043 & 12.842 kJ/mol.K) and negative values of enthalpy (-0.944 & −1.113 kJ/mol) and free energy (-14.60 to −13.55 kJ/mol) confirmed the spontaneous sorption at all temperatures. The simulation results agreed with the sorption results. Also, the modeling was used to ascertain the supramolecular mechanism, which involved hydrogen bonding and π-π interactions.

Application of layered double hydroxide enriched with electron rich sulfide moieties (S2O42−) for efficient and selective removal of vanadium (V) from diverse aqueous medium

The preparation of an adsorbent with highest efficiency, selectivity and stability is usually a challenging task. Herein, we prepared a thio functionalized layered double hydroxide (LDH) denoted as S2O4 LDH by intercalating a strong reducing agent (S2O42−) in the interlayers of trimetallic LDH and was applied to capture vanadium (V(V)) oxyanions from aqueous medium of diverse conditions. The successful preparation of the adsorbent was first confirmed using XRD, FTIR, EDX and CHS analyses. The results revealed that the modified LDH showed excellent performance at a wider pH range which can avoid the tedious work of adjusting pH in actual industrial wastewater treatment. The adsorption capacity was increased with temperature and obtained 379.55 mg/g at 323 K comparing to 112.3 mg/g at 293 K. The adsorption isotherm was better fitted to Langmuir model which suggested monolayer adsorption behavior. At lower temperature (293 K), the sorption kinetics were fitted to a pseudo-first order reaction model which implied physisorption reaction while at higher temperatures (303 and 323 K), the reaction order fitted to pseudo-second order reaction model which highlighted the chemisorption reaction mechanism. As confirmed using XRD, FTIR, EDX and XPS instrumental techniques, the dominant removal mechanism of V(V) involved ion-exchange and partial reduction reactions to nontoxic and less soluble V(IV) and V(III) species due to the low valent sulfur group and followed adsorption in S2O4 LDH. The prepared adsorbent showed very good selectivity towards V(V) in the presence of different co-existing ions both in synthetic wastewater and spiked real water samples. This novel adsorbent also exhibited high recyclability and obtained >90.0% removal of V(V) after four consecutive adsorption–desorption cycles due to the unique memory effect of the LDH. We believe that this strategy provides a new direction to find highly efficient and selective materials for capturing vanadium ions from wastewater of diverse conditions.

Removal of methylthioninium chloride dye from aqueous solution using cogon grass as adsorbent

The aim of this study was to investigate the removal Methylthioninium Chloride dye using cogon grass to treat the effluent. The effects of various parameters such as adsorbent dosage, dye concentration and contact time were studied. Funtional group properties of cogon grass had been characterized using Fourier transform infrared spectroscopy (FTIR). The adsorption process attained equilibrium around 50 minutes. The maximum adsorption capacity was calculated to be 46.30 mg/g with optimized condition of adsorbent dosage 0.1 g at temperature 30 °C for 50 minutes. The adsorption kinetics of Methylthioninium Chloride with cogon grass suit into non-linear pseudo-second order reaction model that refers to the amount of adsorbate and amount of solute adsorbed on adsorbent surface at equilibrium. It was also found that the Langmuir isotherm fit better (R 2 = 0.9959) compare to the Freundlich isotherm (R 2 = 0.4093). The high levels of color removals were achieved with low contact times; and the cogon grass can be effectively used as adsorbent of methylthioninium chloride in aqueous solutions. These results prove that cogon grass is highly potential to be used as low-cost adsorbent for the dye removal from industrial wastewater.

Alkali-cation-incorporated and functionalized iron oxide nanoparticles for methyl blue removal/decomposition

Enhancing the rate of decomposition or removal of organic dye by designing novel nanostructures is a subject of intensive research aimed at improving waste-water treatment in the textile and pharmaceutical industries. Despite radical progress in this challenging area using iron-based nanostructures, enhancing stability and dye adsorption performance is highly desirable. In the present manuscript alkali cations are incorporated into iron oxide nanoparticles (IONPs) to tailor their structural and magnetic properties and to magnify methyl blue (MB) removal/decomposition capability. The process automatically functionalizes the IONPs without any additional steps. The plausible mechanisms proposed for IONPs incubated in alkali chloride and hydroxide solutions are based on structural investigation and correlated with the removal/adsorption capabilities. The MB adsorption kinetics of the incubated IONPs is elucidated by the pseudo second-order reaction model. Not only are the functional groups of –OH and –Cl attached to the surface of the NPs, the present investigation also reveals that the presence of alkali cations significantly influences the MB adsorption kinetics and correlates with the cation content and atomic polarizability.

Fluoride removal using a chelating resin containing phosphonic-sulfonic acid bifunctional group

S9570-Fe(III), a modified chelating resin containing sulphonated monophosphonic acid bifunctional groups, was used for the fluoride removal from aqueous phase for the first time. The results specified that S9570-Fe(III) exhibited better adsorption towards the fluoride ions as compared to the other commonly used chelating resins having monofunctional group such as iminodiacetic acid, sulfonic acid or carboxylic acid. Adsorption thermodynamic and kinetic studies of S9570-Fe(III) chelating resin for the fluoride also have been carried out. The thermodynamic results demonstrated that the adsorption was a spontaneous process accompanied with a gradual decrease in entropy and the low temperature was favorable for the fluoride ion adsorption. The kinetic experiments showed that the resin exhibited a rapid initial adsorption behavior and the adsorption process more complied with the pseudo-second order reaction model which indicating that the whole adsorption process was controlled by a combined mechanism of intraparticle diffusion and chemical sorption. Adsorption mechanism of S9570-Fe(III) resin for fluoride ions was predicted. The study demonstrated the effectiveness of the phosphoric-sulfonic acid bifunctional group chelating resin to remove fluoride, and provided a novel type removal method for the fluoride.

English

Toxic metal ions have lethal effects on all forms of life and these metal ions could enter the food chain when untreated waste effluents are discharged into the environment. In recent years, the use of low-cost adsorbent materials has been widely investigated in search of replacement for the costly methods that are currently used for removing these toxic metal ions from waste streams. In this study, the remediation of chromium ions from electroplating effluent was studied under static conditions using a copolymer material that was derived by grafting polyacrylic acid and polyacrylamide onto the cellulosic backbone of brewers spent grain (BSG). Batch experiments were carried-out using effluents with different concentrations of chromium ions, specifically 25, 50, 75, 100 and 125 mg/L. The results revealed that the optimum sorption of chromium occurs at pH 3.0 and absorbent-adsorbate contact time of 1.5 h gave maximum adsorption regardless of the metal ion concentration in the effluent. The kinetic data fit the pseudo-second order reaction model, suggesting that chemosorption was the rate limiting step for the sorption of chromium ions onto BSG-g-poly (acrylic acid –co- acryl amide). The isotherm studies showed that the Langmuir model gave the best fit to the experimental data, with qmax value of 15.58 mg/g after 5 h of effluent contact with the absorbent material. The results obtained in this study have shown that BSG-g- poly (acrylic acid –co- acryl amide) has a lot of potentials for application as an alternative adsorbent material for the remediation of chromium ions from electroplating waste streams. Key words: Adsorption, chromium, electroplating, effluent, brewers spent grain, studies. &nbsp

Kinetics and Adsorption Isotherm Studies of Methylene Blue Photodegradation Under UV Irradiation Using reduced Graphene Oxide- TiO2 Nanocomposite in Different Wastewaters Effluents.

In this study TiO2@rGO nanoparticles was synthesized as an effective photocatalyst. Reduced graphene oxide (rGO) was mixed with TiO2 with different doping ratio (1%, 3% and 5% wt) and utilized to remove MB dye as organic pollutants from different wastewater effluents and also from aqueous solution. The impacts of different factors, e.g. pH of solution, contact time, photocatalyst dose and initial MB dye concentration on the removal efficiency were studied. The results showed that the highest MB degradation occurred at pH 9, contact time = 120 min, dose of photocatalyst of 0.75 g/L at 30 mg/l dye concentration. Also, the prepared nanocomposites success in reducing COD values of wastewater in the range of 30 – 89.1 %. Moreover, the data of kinetics studies indicated that the adsorption process well obeys the pseudo-second order reaction model with qe values ranged between 14.28 – 19.37 mg/L. Langmuir isotherm model well describes the behavior of adsorption behavior than Freundlich Model.

Study on the adsorption behavior of glycerin from fatty acid methyl esters by a tertiary amine-type anion exchange resin

A weakly basic anion exchange resin with hydroxylated tertiary amine groups was successfully synthesized and used for the first time in an adsorption study for glycerin in fatty acid methyl esters (FAME). A kinetic study of glycerin adsorption on the resin demonstrated that the resin exhibited a rapid initial adsorption behavior, and the correlation coefficients (r22) of the pseudo-second order reaction model were all greater than 0.98, which indicated the existence of hydrogen bonds through sharing electrons between glycerin and active sites on the resin. The whole process of glycerin adsorption onto the resin was a combination mechanism involving hydrogen bond sorption and intraparticle diffusion. The thermodynamic experiments showed that the glycerin adsorption onto the resin was a spontaneous exothermic process accompanied with a gradual decrease in entropy. In addition to intraparticle diffusion, the adsorption behaviors of the resin for glycerin also involved hydrogen bond forces between the OH in the glycerin molecule and N atom in the N(CH3)2 group, glycerin intermolecular hydrogen bond attraction, the dipole bond forces between glycerin and the N(CH3)2 group (90.96%) in the resin, and the dipole bond forces between glycerin and several of the N(CH3)3+ groups (9.04%) in the resin.

Preparation of cellulose acetate blended with chitosan nanostructured membrane via electrospinning for Cd2+ adsorption in artificial wastewater

This study focused on using chitosan (CS) as the functional polymer in the cellulose acetate (CA) matrix to provide reactive ion exchange sites for heavy metal ions. Pure CA and CA/CS blends (wt % 95:5, 90:10 and 85:15) were electrospun to determine the most qualified blend for the adsorption experiment. The morphologies of the electrospun nanostructured membranes were investigated using Scanning Electron Microscopy. The average fiber diameter was found to decrease with increasing CS concentration. CA and CS interaction was confirmed using Fourier Transform Infrared Spectroscopy. Upon characterization, the blend with 15% CS had the best properties for the adsorption process. The adsorption capacities of pure CA and CA/CS blend at different membrane loading and initial concentration showed a significant increase from 67.25 mg Cd2+/g pure CA membrane to 110.48 mg/g CS doped membrane. The experiment revealed that the adsorption kinetics of pure CA and CA/CS blend for Cd2+ were described by the pseudo-second order reaction model. The adsorption isotherm data for Cd2+on the surface of pure CA and CA/CS blend best fit the Freundlich isotherm and can be used to describe adsorption of Cd2+. This study produced an innovative nanostructured membrane for the removal of Cd2+ in wastewater.

Removal of Cr (VI) from Simulated and Leachate Wastewaters by Bentonite-Supported Zero-Valent Iron Nanoparticles.

Zero-valent iron (Fe0) nanoparticles (NPs) have shown excellent ability to remove contaminants hexavalent chromium (Cr(VI)) from aquatic systems. Use of support materials can help to prevent oxidation and aggregation of Fe0NPs, and thus enhance their remediation efficiency. However, most previous studies were conducted using artificially synthetic wastewater, and little is known on the remediation effects of supported Fe0NPs on actual wastewaters containing Cr(VI). Here, bentonite-supported Fe0NPs (BFe0NPs) with 1–5% of bentonite were prepared and characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Batch experiments were performed to study Cr(VI) removal by the selected BFe0NPs from a simulated wastewater and a leachate wastewater originating from a Cr slag heap-polluted soil. The results show that Fe0NPs were uniformly dispersed on the bentonite, leading to a decreased aggregation of NPs, and the optimal mass ratio of bentonite was 4%. Batch experiment results show that lower pH values favored Cr(VI) removal by BFe0NPs. The removal percentage of Cr(VI) was higher than 90% for both wastewaters when the pH value was 2.0, but decreased significantly as pH value increased. Cr(VI) removal reaction was quite fast within the initial 10 min, and at least 85% of Cr(VI) was removed for both wastewaters. Cr(VI) removal percentage increased with increasing BFe0NPs dosages ranging from 30 to 60, but remained almost unchanged when the Fe/Cr mass ratio increased to above 60. The reaction of BFe0NPs to remove Cr(VI) followed the pseudo second-order reaction model. In most cases, the removal rates of Cr(VI) were higher in simulated wastewater than in leachate wastewater, but all approached 100% at the optimal conditions. Our present results show that BFe0NPs with 4% bentonite are efficient for treatment of Cr(VI)-containing wastewaters.

Kinetics and Isotherm Studies of Liquid Phase Adsorption of Cationic Dye onto Chitosan Synthesized from Crab Shells

The use of cheap and eco-friendly adsorbents studied as an alternative to activated carbon for removal of dyes from wastewater is the focus of this paper. Chitosan, which was produced from food industry waste (crab shells), was synthesized, characterized and utilized as adsorbent to remove cationic dye, basic blue, from wastewater by adsorption. Characteristics of the synthesized chitosan biosorbents was established using scanning electron microscope (SEM), and Fourier Transform Infra-Red (FTIR) spectroscopy. Experiments were conducted in batch forms to investigate the effects of contact time, initial dye concentration and adsorbent dosage. Kinetic and isotherm analysis of the adsorption process were also carried out. The results obtained revealed that removal efficiency of the chitosan was increased as the contact time and chitosan biosorbent dose were increased, but a decrease with increasing initial concentration of basic dye was observed. The pseudo-second order reaction model was found to describe the biosorption process best, with chemisorption as the rate limiting step. The maximum colour removal efficiencies of chitosan at dosage of 4 g for time duration of 90 min was found to be 91.88% of the dye from a solution of 80 ppm. The pseudo-second order kinetic model was also seen to agree very well with the dynamic behaviour of the adsorption of basic blue on chitosan under different contact time, initial dye concentrations and adsorbent dosages. The dynamic behaviour of adsorption of basic blue onto chitosan has the model fitness in the following order: pseudo-second order > Elovich model > pseudo-first order. The Elovich equation was found to be the best fit equilibrium isotherm for the sorption of basic blue onto chitosan based on linearized correlation coefficient. Moreover, the equilibrium isotherm has its model fitness to be in the order of Elovich model > Langmuir model > Freundlich model.

Kinetic Study of COD in Coking Wastewater on Lignite Activated Carbon

The adsorption kinetics and adsorption mechanism of the activated carbon on COD were studied. The reaction kinetics of lignite activated carbon at different temperatures is verified by pseudo first order reaction and pseudo second-order reaction model, and the rate constants of these dynamics models are fitted. The results showed that the adsorption can be expressed by the pseudo-second-order model, the equilibrium adsorption is 50.8mg/g at 98K temperature, the adsorption process is the exothermic process. Finally, the activation energy of the adsorption process is calculated as 5.76kJ/mol, and the adsorption process is physical adsorption.

Determination of Sorption Properties of Heavy Metals in Various Biosorbents

Abstract Various techniques of determination of properties of physicochemical processes of heavy metal sorption in biosorbents were analysed. The methods of preparing and storing samples, conditions of experiment performance, as well as the methods of data interpretation were discussed. Two procedures of study were analysed: (1) in the static system of biosorbent-solution contact and (2) in the system of dynamic flow of solution. Copper cation sorption was studied. The effect of consecutive stages of the study on the quality of final results was shown. A high degree of uncertainty of the sorption capacity assessment was reported, which was dependent on the manner of conducting the study. The application of the pseudo-second order reaction model was substantiated to describe kinetics of cation-exchange sorption and the model of Langmuir isotherm to describe equilibria. The study conducted reveals that in order to perform comparative analyses, it is necessary to establish a joint concept of conducting studies and the interpretation of results.

One-Step Fabrication of Magnetic Carbon Nanocomposite as Adsorbent for Removal of Methylene Blue

Magnetic Fe3O4@C nanocomposites with well-defined core@shell structure were synthesized via a facile one-step solvothermal process using ferrocene as both iron and carbon resource in the presence of hydrogen peroxide (H2O2). The as-prepared Fe3O4@C nanocomposites were employed as adsorbent materials for removal of methylene blue (MB) from aqueous solution. Several experimental parameters, including contact time, acidity of the solution, and initial MB concentration were investigated. The result showed that the equilibrium uptake of MB was related to the MB initial concentration as well as acidity of the solution. The adsorption kinetics of MB was dominated by the pseudo-second order reaction model. Significantly, the synthesized Fe3O4@C nanocomposites could be easily isolated from the adsorption system after adsorbing MB and showed prominent reusability. All results indicated that the prepared Fe3O4@C composites had the potential to be used as adsorbents for the removal of dye pollutant from wastewater.

Adsorptive Removal of Reactive Black 5 from Wastewater Using Bentonite Clay: Isotherms, Kinetics and Thermodynamics

The studies of the kinetics and isotherms adsorption of the Reactive Black 5 (RB5) onto bentonite clay were explored in a batch study in a laboratory. The maximum RB5 adsorption conditions of bentonite clay were optimized such as shaking speed (100 rpm), temperature (323 K), pH (10), contact time (40 min), initial dye concentration (170 mg·L−1), and particle size (177 µm). The adsorbent surface was characterized using Fourier Transform Infrared Spectroscopy spectroscopy. The mechanisms and characteristic parameters of the adsorption process were analyzed using two parameter isotherm models which revealed the following order (based on the coefficient of determination): Harkin-Jura (0.9989) > Freundlich (0.9986) and Halsey (0.9986) > Langmuir (0.9915) > Temkin (0.9818) > Dubinin–Radushkevich (0.9678). This result suggests the heterogeneous nature of bentonite clay. Moreover, the adsorption process was chemisorption in nature because it follows the pseudo-second order reaction model with R2 value of 0.9998, 0.9933 and 0.9891 at 25, 75 and 100 mg·L−1 RB5 dye in the solution, respectively. Moreover, based on the values of standard enthalpy, Gibbs free energy change, and entropy, bentonite clay showed dual nature of exothermic and endothermic, spontaneous and non-spontaneous as well as increased and decreased randomness at solid–liquid interface at 303–313 K and 313–323 K temperature, respectively.

Incorporation of selenium(IV) and selenium(VI) on uranyl peroxide

The sorption of Se(IV) and Se(VI) on uranium peroxide has been studied considering the sorption kinetics, the sorption isotherms and the effect of pH. Selenium sorption on studtite is fitted with a pseudosecond order reaction model; in addition, two different mechanisms seem to influence the sorption process: micropore diffusion and intra-particle diffusion. Both selenium(IV) and selenium(VI) are sorbed on studtite through a monolayer coverage. Sorption is higher at acidic pH than at alkaline pH. This behaviour is consistent with the chemical speciation of selenium in solution and with the acid–base properties of the solid.

Assessment of toxic copper(II) biosorption from aqueous solution by chemically-treated tomato waste

Abstract Agricultural wastes or industrial wastes can be used as biosorbent with quite little processing when they are locally available in large quantities. A great number of studies were done to uptake copper(II) ion from aqueous solutions. The biosorption of copper(II) ion from aqueous solutions by hydrochloric acid treated tomato factory waste was investigated to identify metal ion removal efficiency of biosorbent for the first time in the literature. Proximate analysis of tomato waste was performed; also waste and biosorbent were characterized by applying Fourier transform infrared spectroscopy and elemental analyses. pH, biosorbent dosage, initial metal concentration, temperature and contact time effects were examined to determine optimum conditions of copper(II) uptake. According to the pH effect experiments, the maximum % metal removal was achieved at pH 8 as 92.08%. Optimum biosorbent dosage and initial copper(II) concentration were found as 0.2 g/50 mL solution and 50 ppm, respectively. Langmuir adsorption isotherm was found to best fit the adsorption data; and also reaction kinetics was determined to be appropriate to the pseudo-second order reaction model. Thermodynamic functions, the change of free energy (Δ G °), enthalpy (Δ H °) and entropy (Δ S °) of biosorption were calculated for copper(II) ion. The results showed that the biosorption of copper(II) ion on tomato waste biosorbent was exothermic at 293–313 K. Results of biosorption studies are in line with the literature. A promising outcome based on experiments shows that, tomato waste could be used as an alternative and low-cost biosorbent for removal copper(II) ion from aqueous solutions, when suitable conditions are performed.