Initial Heavy Metal Concentration Research Articles

Heavy Metal Adsorption and Release on Polystyrene Particles at Various Salinities

Microplastics (MPs) and heavy metals are two major types of pollutants that interact with each other, but they are poorly understood. Polystyrene (PS) is one type of MPs that is often detected in aquatic environments. In this study, we examined the adsorption capacity and release rate of heavy metals with respect to different particle sizes of PS, heavy metals, initial heavy metal concentrations, and salinities. Virgin (new) PS with diameters of 20, 50, 130, and 250 μm was used in this study, and four heavy metals (lead, cadmium, copper, and zinc) were used. The results showed that larger PS particle sizes adsorbed more heavy metals even though it took longer to achieve equilibrium adsorption. An increase in heavy metal concentration caused the adsorption capacity (μg g–1) of PS particles to also increase, but the adsorption rate (%) decreased. Increased salinity of the heavy metal solution resulted in a slower adsorption time and a lower adsorption capacity and release rate from the surface of PS particles. Different heavy metals also had different adsorption capacities. Pb was consistently more highly adsorbed by MPs, followed by Cu, Zn, and Cd. Larger PS sizes released heavy metals faster than smaller PS sizes, and the amounts of heavy metals released were higher. The heavy metal with the highest release rate was Cd, followed by Pb, Cu, and Zn. Finally, our findings highlight the interactions between PS and heavy metals and strongly support that PS particles can act as vectors for heavy metals in aquatic systems.

Design and characterization of PANI/starch/Fe2O3 bio composite for wastewater remediation

A new synthesized polyaniline/starch/hematite bio composite (PANI/S/Fe2O3 BC) has been studied as an effective material for on-site water remediation. PANI/S/Fe2O3 BC was developed by combining the techniques of co-precipitation and interfacial polymerization in the presence of aqueous starch solution in an acidic medium under ultrasonic irradiation. The nano-morphologies and structures of the designed PANI/S/Fe2O3 BC were evaluated by various techniques relative to PANI and Fe2O3 nanoparticles. In single and multiple systems, PANI/S/Fe2O3 BC was evaluated as a possible adsorbent for different heavy metals, including As3+, Zn2+, and Co2+, relative to PANI and Fe2O3 nanoparticles. In terms of pH value, operating temperature, initial heavy metal concentration, contact time, adsorbent dose and competitive ions in the solutions, the adsorption process was optimized. For 92% overall adsorption of Co2+ and 100% overall adsorption of both As3+ and Zn2+, the adsorption equilibrium was achieved within 60 and 120 min, respectively. In addition, adsorption thermodynamic analysis shows that the As3+ ions adsorption process was not random and the pseudo-second-order fitted with experimental results. Moreover, PANI/S/Fe2O3 BC was evaluated as an antibacterial agent against Gram-negative bacteria (Salmonella typhimurium) and Gram-positive bacteria (S. aureus, Methicillin-Resistant Staphylococcus, Aureus Clinical isolate and Bacillus subtilis). The reported performances indicated that the PANI/S/Fe2O3 BC is a potent candidate for industrial water bioremediation.

Application of Artificial Neural Network and Particle Swarm Optimization for modelling and optimization of biosorption of Lead(II) and Nickel(II) from wastewater using dead cyanobacterial biomass

Removal of heavy metals through biosorption using biomass offers several advantages over other conventional techniques such as low cost, high efficiency, environmentally friendly, etc. In the present article, biosorption of Nickel(II) and Lead(II)was investigated using dried biomass of cyanobacterial consortium. OFAT (one-factor-at-a-time) analysis was used to assess the effect of input parameters on the removal of potentially toxic elements by varying initial metal ion concentration (2–10 mgL−1), adsorbent dose (0.1–1.0 gL-1), pH (for Pb(II): 2–6, for Ni(II): 2–8) and temperature (25°C–45°C) individually, at constant shaking speed of 150 ​rpm. Results showed that removal using biomass attained highest values in as short time as 15 ​min. The investigations also showed the removal is highly effective at lower initial concentrations of heavy metals. Maximum removal of Lead(II) (87.27 ​± ​1.75%) and Nickel(II) (92.57 ​± ​0.77%) was obtained at pH 6 and 45°C and at pH 7 and 25°C, respectively, within 15 ​min with 0.1 gL-1 biomass. Both the Langmuir model and Freundlich model were seen to fit the equilibrium data. Further, Artificial Neural Network was used to model the biosorption process. Subsequently, Particle Swarm Optimization was applied to optimize the operating conditions for the removal of both the metals.

Enhanced coagulation coupled with heavy metal capturing for heavy metals removal from coal gasification brine and a novel mathematical model

The wastewater reuse and industrial salt recovery from coal gasification brine (CGB) is the last step for the zero liquid discharge (ZLD) of coal chemical wastewater, and the heavy metals removal is the key limiting factor for the ZLD process. In this research, heavy metals were removed by using the enhanced coagulation coupled with heavy metal capturing technology. Step by step, the optimal type and dosage of chelating agent and flocculant, as well as the optimal coagulant dosage was determined via the single-factor method. Additionally, the impacts of critical water quality parameters (temperature, pH, salinity and organics, etc.) on the removal of heavy metals were also investigated. Finally, the model targeted the removal of total arsenic (As) was constructed by four-factor quadratic regression orthogonal rotation combination design. The initial heavy metal concentration, the amount of heavy metal chelating agents (HMCAs), the amount of flocculant and the amount of coagulant were taken as independent variables, while the total As concentration of effluent was taken as the dependent variable, obtaining the significant regression equation: Y =0.1165 + 0.04187x1-0.01829x3+0.00941x22+0.0116x32-0.00719x2x3 (F2 = 264.22380, p＜0.01). The results demonstrated that appropriate amount of HMCAs and flocculant determined removal efficiency of heavy metals.

Novel green chitosan-pectin gel beads for the removal of Cu(II), Cd(II), Hg(II) and Pb(II) from aqueous solution

Chitosan-pectin gel beads (CPBs) were synthesized via a facile and green method and applied to remove heavy metals from aqueous solution. The structural characteristics of CPBs were investigated by SEM and FTIR, the mechanical strength of CPBs was measured by Texture Analyzer and the stability of CPBs was evaluated in acidic solution. To study the adsorption characteristics, the effect of pH, contact time, initial heavy metals concentration, temperature, adsorption mechanism and regeneration were systematically investigated. The adsorption kinetics fitted well pseudo-second-order model, and the adsorption isotherms were well described by Langmuir model. The maximum adsorption capacities of Cu(II), Cd(II), Hg(II) and Pb(II) were 169.4, 177.6, 208.5 and 266.5 mg/g, respectively. The adsorption-desorption experiments revealed that the CPBs exhibited a great reusability. Thus, the synthesized CPBs in this study had the potential to be utilized as an environment-friendly and green adsorbent for the removal of heavy metals.

AN EGGSHELL HYDROXYAPATITE - GRAPHENE OXIDE NANOCOMPOSITE FOR THE REMOVAL OF HEAVY METALS FROM WASTE WATER

Heavy metal pollution is a serious environmental problem that can be remediated by various adsorbents. So, a new hydroxyapatite / graphene oxide nanocomposite (HAp/GO) material was synthesized from waste eggshell as a green and eco-friendly adsorbent for the effective removal of heavy metals (e.g., Cd, Pb, Cr, Ni, Co) from wastewaters. Nano-structured HAp was synthesized by calcination of the waste eggshell followed by hydrothermal treatment in the presence of phosphate solution. However, GO was synthesized using the Hummar’s method (Guerrero-Contreras and Caballero-Briones, 2015). The HAp/GO nanocomposite was synthesized from the HAp and GO precursors by ultrasonic treatment. The morphology, composition, crystal structure, functionality and stability of the synthesized sorbent were evaluated using Fourier transform infrared spectrophotometry (FTIR), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectrometry and N2-BET (Barrett–Emmett–Teller) surface area measurement techniques. The equilibrium concentrations of heavy metals were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The effect of the initial concentration of heavy metals, the dosage of HAp/GO, temperature effect and the solution pH on the adsorption capacity was investigated. The synthesized HAp/GO was adopted to achieve superior simultaneous removal efficiencies (≥ 90 %) for (Cd, Pb, Cr, Ni, Co) metal ions. .

Investigation of competitive adsorption and desorption of heavy metals from aqueous solution using raw rock: Characterization kinetic, isotherm, and thermodynamic

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Qmax) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals.

Rapid adsorption of Pb (II) and Cr (VI) from aqueous solution by Aluminum hydroxide nanoparticles: Equilibrium and kinetic evaluation

Pollution of water due to excessive lead and chromium levels in groundwater and wastewater has contributed to severe health issues, which has increased concern over the provision of clean water. There is a dire need for successfully eliminating these pollutants through the use of low-cost and ecosystem-friendly materials. This paper reports the synthesis of aluminum hydroxide nanoparticles of 9.9 nm as calculated through X-Ray Diffraction (XRD) analysis. Fourier-transform infrared spectroscopy (FTIR) and pH of Point Zero Charge (pHPZC) were used to establish nanomaterial and surface charge formation on the material. The effects of the various parameters, i.e., the number of nano adsorbents, contact time, initial heavy metal concentration, and pH, were examined in detail on the lead and chromium removal rate. Kinetic studies were reported to fit better with the second-order kinetics model, and experimental adsorption equilibrium data fitted well with the Freundlich isotherm model under optimized conditions. The maximum removal of 95% for Pb(II) obtained for nano adsorbent dose was: 0.5 g/L, pH: 5.5, initial lead concentration: 10 mg/L at 30 min of contact time, and maximum removal of 97% for Cr(VI) for nano adsorbent dose: 1 g/L, pH: 5, initial: 15 mg/L and 60 min of contact time.

Removal of Zinc and Chromium from industrial wastewater using water hyacinth (E. crassipes) petiole, leaves and root powder: Equilibrium study

Abstract Water hyacinth (Eichhornia crassipes) is known for its rapid invasive growth on surface of water bodies which inturn cause many ill-effects on biodiversity. The current study was performed on the remediation of Zinc and Chromium metal ions from Electroplating Industry Wastewater (EIW) using dried biomass of aquatic macrophyte – water hyacinth. The potential of powdered parts of (leaves, petiole, root) water hyacinth was studied through influential parameters such as biosorbent dosage, initial concentration of heavy metals, initial pH and contact time. Batch adsorption studies were conducted followed by column studies. Biosorbent prepared from root showed maximum Zinc (Zn) removal of 98.9% and stem showed Chromium (Cr) removal of 96.4% respectively. The obtained data was fit into equilibrium studies ie. Freundlich and Langmuir isotherms. Equilibrium studies confirmed the conformity of the adsorption isotherms to Langmuir and Freundlich isotherms for the stem sample in removal of Chromium and the root sample was found to conform to the Langmuir isotherm in removal of Zinc.

Demetallisation of Heavy Metals from Indian Mackerel (R. kanagurta) Fish

Fish especially Indian Mackerel (R. kanagurta) provides protein, essential fatty acids and essential metals that are needed in the human diet, however high concentration of essential metals will cause adverse health effect towards human. Thus, the removal of heavy metals such as lead (Pb) and copper (Cu) from R. kanagurta (Indian mackerel) by using different types of natural waste adsorbents was implemented in this study. Initial concentration of heavy metals (Pb, Cu) in Indian mackerel (R. kanagurta) fish were above the permissible limit set by World Health Organization and Malaysia Food Regulation 1985. Thus, in this study, corncob and eggshell were applied as natural waste adsorbents to enhance the demetallisation process. The result showed only the corncob able to efficiently remove all the heavy metals in Indian Mackerel (R. kanagurta) up to 78.31% compared to the eggshell, which yielded about 71.34%. Besides, this study proved that using corncob; the Cd metal found to be wholly removed from (R. kanagurta) which met the permissible limit set by WHO and MFR.

Adsorptive removal of heavy metals from industrial effluents using cow dung as the biosorbent: Kinetic and isotherm modeling

AbstractThis article investigated an eco‐friendly technique for the removal of heavy metals using biosorbent derived from cow dung. Heavy metals bearing wastewater were collected from a common effluent treatment plant located at Sangariya, Jodhpur (Rajasthan, India) to evaluate the removal efficiency of synthesized cow dung–activated carbon. The prepared activated carbon materials have a high surface area in the range of 948–1072 m2/g and also have significant quantities of micropore and mesopore volumes. Furthermore, pore diameters were in the range of 2.24–2.33 nm. Surface morphology was improved after being treated with NaOH. The adsorbent material was found to be an efficient medium for the removal of Cr(VI) and Cd(II). The results revealed that more than 95.6% of Cr(VI) and 66.88% of Cd(II) were achieved at the optimized condition of pH12.0, initial concentration of heavy metals 10 mg/L, 300 min of contact time, and the dose of 0.2 g/L, whereas only 16.3% removal efficiency was observed for Ni(II). Equilibrium data have been analyzed by Langmuir, Freundlich, Temkin, and Redlich and Peterson (R–P) isotherm models with the help of nonlinear regression analysis. Experimental data were best fitted for Freundlich and R–P isotherms.

Lead and cadmium biosorption from milk by Lactobacillus acidophilus ATCC 4356.

The food and water contamination with heavy metals is increasing due to the environmental pollutions. Lead and cadmium are the toxic heavy metals for humans that can be found in air, soil, water, and even food. Lactic acid bacteria have the ability to remove and diminish the level of heavy metals. In this study, Lactobacillus acidophilus was used to remove lead and cadmium in milk and the capability of this valuable bacterium in biosorption of these metals low concentrations (µg/L or ppb) in milk was evaluated. First, the variables on lead and cadmium removal by this bacterium have been studied by Plackett–Burman design. Then, the bioremoval process was optimized and the three main factors, the bacterium concentration, contact time, and the initial heavy metal concentration were chosen by using a central composite design. The optimum lead and cadmium bioremoval yield of 80% and 75% were observed, respectively, at 1 × 1012 CFU of L. acidophilus in milk at the 4th day and the initial ion concentration of 100 µg/L. The 3D plots analysis showed the interaction effects on metal biosorption. This study showed that L. acidophilus is a natural effective biosorbent for lead and cadmium removal from milk.

PET-microplastics as a vector for heavy metals in a simulated plant rhizosphere zone

Although microplastics (MPs) are ubiquitous contaminants in different ecosystems, their interactions with other pollutants including heavy metals remain relatively unknown. Wheat is an important grain that makes the basis of human food in many parts of the world. Thus, pollutants that affect its production are important subjects of study. This research focuses on the possible effects of the transport of the adsorbed heavy metals onto MPs to the roots of growing wheat. The adsorption of three heavy metals (Pb, Cd, and Zn) onto PET particles was examined. Pb and Cd were selected because they are known to be toxic, while Zn is an essential nutrient for plants. Adsorption experiments were performed using 1 g of PET-MP particles in 20 ml of five different concentrations of each individual element (Pb, Cd, and Zn) (denoted as S-elements). To investigate the antagonistic and synergistic effects of these elements on each other, they were studied collectively with all 3 elements present (denoted as C-elements). Desorption experiments were then performed for three scenarios in which the wheat rhizosphere zone was simulated. Generally, the concentration of the investigated heavy metals adsorption on polyethylene terephthalate (PET) decreased in the order: S-Cd > S-Zn > S-Pb and C-Zn > T-Cd > C-Pb. PET particles exposed to Zn, Cd, and Pb solution adsorbed from 7.2 to 8.5%, 5.3 to 9.8%, and 29.8 to 68.5% of the initial heavy metals concentration, respectively. 11.3 to 15.2%, 12.5 to 23.35%, and 5.5 to 33.6% of the initially adsorbed Zn, Cd, and Pb were desorbed in the wheat rhizosphere zone in the three defined scenarios, respectively. The results show that PET particles can act as a vector in transferring heavy metals to the rhizosphere zone.

Removal of heavy metals from urban soil using functionalized carbon-coated composite

Urban soil accumulates significant contents of heavy metals (HMs), which is a risk to human health and considered as a hindrance for the development and expansion of concerned areas that required to be having simple and field applicable remediation mechanisms with diverse applicable concerning location. A magnetic nanocomposite is fabricated by spherical magnetic ceramsite coated with nanocarbon spheres (MCCS) and functionalized by polyethylene glycol (PEG) for the removal of HMs such as lead Pb(II) and hexavalent chromium Cr(VI) from the contaminated soil. Mesoporous and functionalized magnetic nanocomposite named MCCSPG having plenty of hydroxyl and carboxyl groups are obtained. Box–Behnken design and desirability function are used to optimize maximum adsorption efficiency with three independent factors pH, initial concentration of HMs and initial concentration of MCCSPG. The maximum Langmuir adsorption capacity of MCCSPG is 10.18 mg/g for Pb(II) and 10.05 mg/g for Cr(VI). The pseudo-second-order is fitted the best R2 (0.98) for adsorption kinetics. The MCCSPG showed good reusability efficiency six times and collected from the soil via an external magnetic separation system. Short-term and long-term benefits of MCCSPG are also discussed in the topsoil that facilitates its potential applicability for the in situ remediation strategy.

English

The discharged of lead and cadmium above maximum permissible limits into surface water and environment without any pre-treatment methods has caused severe heath challenges to humanity. In other to minimize the reoccurrence, this research aim to ascertain biosorption capacity of bamboo stem biomass to remove lead and cadmium from aqueous solution. Batch experiment and data evaluation under optimum removal conditions (such as pH, contact time, temperature, biosorbent dosage, initial heavy metal concentration) were determined. Maximum optimum removal was observed for both metal ions at pH 5, 90 min contact time, 298K temperature with 50 ppm of initial concentration for 95.92 and 80.98% removal for lead and cadmium. Lead revealed better results at all concentrations for bamboo stem biomass with increase in percentage removal as concentration of heavy metal increases. Kinetics and isotherms models were applied and this shows that kinetic models are described and fitted well with pseudo-second order reaction while adsorption isotherm model supported Freundlich model with high R2 values. Thermodynamically, biosorption of lead and cadmium was exothermic and lead was greater than cadmium in the order of spontaneity and entropy. From these results, it can be concluded that bamboo stem biomass has been shown to be productive in removal of heavy metals from aqueous solution. Key words: Biosorption, bamboo stem biomass, heavy metals, kinetics, isotherms, thermodynamics. &nbsp

Optimizing binary biosorption of cobalt and nickel ions on brown algae using a central composite design

One of the most valuable approaches to eliminate heavy metal ions from aqueous solutions is biosorption. Cobalt and nickel can be removed from aqueous solutions simultaneously using sodium chloride-treated Cystoseria indica, which is a kind of brown algae. Three parameters, including pH, initial concentration of heavy metals, and adsorbent mass, were designated to run batch adsorption experiments. The central composite design was employed to show the simultaneous change of all factors according to a pre-specified experimental matrix that creates a response model in which the interactions between the calculated responses and each variable as well as interaction influences, are revealed. R2 values for the computed model were 0.96 and 0.95 for the response surface 1 (cobalt) and 2 (nickel), respectively. Central composite design calculated the optimum adsorption process as pH, 5.9; biomass dosage, 0.06 g; initial nickel concentration, 91.94 mg/l; and initial concentration of cobalt 89.36 mg/l. The kinetic and isotherm models were engaged to evaluate the equilibrium data at the optimum condition. The biosorption of both heavy metal ions obeyed the intra-particle diffusion kinetic model best, with the equilibrium adsorption time at 80 min. The extended Freundlich isotherm model is better fitted for the equilibrium biosorption data of nickel and cobalt ions. The maximum biosorption of nickel and cobalt ions simultaneously at optimized condition was 69.99 and 75.21 mg/g, respectively.

Production and characterization of carbon-based adsorbents from waste lignocellulosic biomass: their effectiveness in heavy metal removal

In this study, hazelnut shell and walnut shell which are the agricultural wastes existent abundantly in many countries were pyrolyzed at different temperatures in the temperature range of 400–700 °C in order to optimize the physicochemical properties of biochars. The biochars with large surface area were used to removal of lead (Pb2+) ions, one of the most important heavy metal pollutant, from aqueous solutions. The characterization of raw biomass and also biochars produced by pyrolysis were performed using FT-IR, BET, SEM, partial and elemental analysis techniques. In order to determine the adsorption characteristics of both biochars, batch adsorption experiments were carried out under different experimental conditions. The optimum conditions were determined by investigating the effect of adsorption parameters (initial heavy metal concentration, temperature, adsorbent amount, pH, contact time and mixing speed) for efficient removal of Pb2+ ions from aqueous solution. The experimental results were investigated in terms of Langmuir, Freundlich and Temkin isotherm models. Together with the calculated thermodynamic parameters, the adsorption mechanism was tried to be explained. In order to determine the kinetic model of the adsorption process, the experimental data were applied to pseudo first-order, pseudo second-order and intra-particle diffusion model, and the model constants were investigated.

Using modified macadamia carbon by H2O2 as adsorbent to remove zinc (Zn2+) in wastewater

Using modified macadamia carbon by H2O2 as adsorbent to remove Zn2+ with H2O2 25% in 48 hours. The Parameters, such as pH, dosage and adsorption time affect the processing ability of modified macadamia carbon H2O2. The maximum removal efficiency of 64.52% was obtained at a pH of 4.5, the processing time is 80 minutes, dosage 1.8 g/L and an initial heavy metal concentration of 25ppm.

Efficiency of ozonation process with calcium peroxide in removing heavy metals (Pb, Cu, Zn, Ni, Cd) from aqueous solutions

Heavy metal ions have deadly effects on all forms of life, and through the disposal of industrial wastewater, they enter water resources and, eventually, the food chain. Advanced oxidation processes can remove hazardous and non-degradable organic pollutants in aqueous solutions. Variables examined were initial concentrations of calcium peroxide and heavy metals, contact time, pH, and ozonation rate. Maximum removal rate of heavy metals by ozonation with calcium peroxide under optimal conditions (contact time = 90 min, pH = 3, heavy metal concentration = 25 mg/L, calcium peroxide concentration = 0.025 mg/L and ozonation rate = 1 g/min) in synthetic and real samples were respectively 89.8% and 64.6% for Pb, 92.1% and 73.9% for Cu, 90.4% and 69.7% for Ni, 86.9% and 59.1% for Cd, and 93.4% and 78.8% for Zn. Maximum COD removal rates in synthetic and real samples were 88.1% and 69.9%, respectively. Removal rates of heavy metals and COD under optimal conditions on wastewater from the Isfahan electroplating industry and steel company were determined. The use of the ozonation process with calcium peroxide can be recommended as a good, coefficient method for the removal of heavy metals in wastewater treatment.

Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems

Abstract Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste disposal. The properties of peanut shell-derived biochar (PBC) under different temperature and its adsorption capacity of heavy metals were investigated. It was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional groups. Furthermore, the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions, sorption capacity decreased as Pb2+ > Cu2+ > Cd2+ > Ni2+ > Zn2+, which was lower than in a single solute. The adsorption process using selected biochar was optimized with respect to pH, reaction time, adsorbent dose, and initial concentration of heavy metals. The kinetic data was well fitted with PSO model, and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals, which indicated that the removal course was primarily explained by monolayer adsorption, and chemical adsorption occupied an important role. Therefore, peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.