---

Background and purpose: According to thetheory ofsustainable development, protect the environmentforcurrent and futuregenerationsisinevitable. Chromium (VI) is one of the pollutant of waterthatcauseharm totheaqueous environmentandrisksfor human health, animalsand plants. The purpose of this study was tosynthesis of Fe3O4 nanoparticlesand evaluateofCr (VI) adsorptionon Nanoparticle ssynthesizedasanadsorbent. Materials and methods: Inthisexperimental- laboratorystudy, nanoparticleswere synthesized bychemicalco-precipitation method and as an adsorbent was studiedforadsorptionof Cr (VI).The resulted nanomaterials were characterized by SEM, XRD and FT-IR. Effects ofpH, contacttime, adsorbentdoses andinitial Cr (VI) concentration werestudied. The resulting data were described by the Langmuir and Freundlich isotherm models and for Data analysis was used from Excel software. Results: The results showedthat thecharacterization ofnanoparticleswereas expectedandthe best of removal performance in pH= 2, at contact time equal10 min, adsorbentdose of 1g/L and initial Cr (VI) concentration of50 mg/L.The Pattern of Cr (VI) adsorption was fitted with the Freundlich model and Adsorption processes followed the pseudo second-order kinetics. Conclusion: chemical co-precipitation Synthesis methodbased onlow power consumptionandShort time isaappropriate methodandFe3O4nanoparticlessynthesizedby this methodcan be used as asuitable optionfor theadsorptionof Cr (VI).

---

Background and purpose: Dyes and cyanide are the most important sources of environmental pollution, found in industrial wastewater, which are harmful for human health and environment. The purpose of this research was to investigate the Kinetic and efficiency of titanium dioxide photacatalytic process in removal of Reactive Black 5 (RB5) dye and cyanide from aquatic solution in a batch system.
Materials and methods: This research was an applied-fundamental study. Â reactor was designed and optimum dosage of TiÔ2 was determined, 1g/L keeping other parameters constant. The effect of pH, contact time and initial Reactive Black 5 )RB5) dye and cyanide concentration was studied at a constant concentration of TiÔ2 (1 g/L).
Results: The result showed that removal efficiency of Reactive Black 5 )RB5) dye and cyanide decreased with increasing pH and initial Reactive Black 5 )RB5) dye and cyanide concentration. There was also an increase in specific removal efficiency by increasing the contact time and the TiÔ2 dosage. Ïn addition, kinetic parameters were obtained by application of Langmuir and Hinshelwood equation.
Çonclusion: The results showed that removal of Reactive Black 5 )RB5) dye and cyanide can be efficiently performed by ÜV/TiÔ2

---

Background and purpose: Despite relative neutrality of metal gold in chemistry reactions, there is a concern about skin absorption and toxicity of gold nanoparticles that nowadays are increasingly used around us. On the other hand, judging from liver detoxification, in this study, the histological alterations of liver and their enzymes and blood cells were investigated in mice by touch of gold nanoparticles. Material and Methods: The backs of 32 male mice were shaved and then were divided into control group in which their back skins were touched with 0.2ml/day distilled water and 3 groups (25, 50,100 ppm) that were being treated with 0.2 ml/day of gold nanoparticles with mentioned doses and 10 nm diameter for 14 days. Finally, their blood was taken for hematology and biochemistry tests and their livers were removed for histopathology tests. Results: To compare the liver tissues of the control group with 3 other groups showed some abnormalities in liver tissues of all treated groups that in 50 & 100 ppm were significant. The levels of two liver enzymes (ALT,AST) and CBC (complete blood count) of control group in comparison with 3 other groups showed that ALT enzyme levels in 50 &100 ppm groups had increased but the levels of ALT & AST in other groups decreased (not significant) and also the values of CBC test showed no significant differences. Conclusion: Touch of gold nanoparticles and conditions of this study has toxic effect on the liver of male mice. So, this has a hazard potential.

---

Background and purpose: Human hepatocellular carcinoma (HCC) is one of the most common causes of death in the world. Targeted drug delivery to cells, tissues or specialized receptor cells is an advanced technology in treatment of HCC. The purpose of this study was to investigate the cytotoxicity properties of DTX nanoparticles. In this research nanoparticles were prepared through radical polymerization. Materials and methods: HepG2 cells were seeded in 96-well plates at a density of 10,000 viable cells per well. Then 0.01-0.50 µg/ml of the nanoparticle and the free drug was added the day after seeding. Afterwards, the number of viable cells was counted and the activity of mitochondrial dehydrogenase enzymes of the cells was detected in 24, 48 and 72 hrs using MTT assay. Results: The results of MTT assay showed strong and dose-dependent inhibition of HepG2 carcinoma cell growth of the nanoparticle compared with DTX. Inhibitory concentrations (IC50) that was obtained for nanoparticles and free drug incubation times of 24, 48 and 72 hours were 1.02 ± 0.68, 0.39 ± 0.86, 0.20 ± 0.93 and 10.39 ± 1.34, 8.87 ± 0.97, 5.99 ± 0.76 µg/ml, respectively. Conclusion: The results showed higher cytotoxity effect of nanoparticles in comparison with free drug against HepG2 cell lines in all mentioned incubation times. Hence, thiolated-chitosan nanoparticles could be a potentially useful delivery system for docetaxel as an anticancer agent in treatment of liver cancer.

---

Background and purpose: The widespread use of silver nanoparticles in therapeutic and diagnostic methods has created some concerns. Different sizes and shapes of nanoparticles have different effects. In this investigation, toxic effects of spherical nanosilver with average diameter of 4 nm were investigated on MCH and HGB in male Wistar rats. Materials and methods: In this study, concentrations of silver nanoparticles at 50,100, 200 and 400ppm were applied through skin contact for the treated groups. Then blood sampling of the inner corner of eye was performed in rats using capillary tube. The mean of MCH and HGB in the treatment and control groups were recorded on day 12 after treatment and ANOVA test was used to analyze the data. Results: Blood damage caused by skin contact with silver nanoparticles in rats resulted in stimulated red blood cells in all groups. Significant differences were found for dose concentration in the MCH 200ppm on day 12 after the treatment (P<0.05). However, there were no significant differences in HGB among the studied groups. Conclusion: In 50ppm concentration of nanosilver, possible mechanisms of the change MCH are releasing free radicals, oxidative stress and apoptosis in red blood cells. Further studies are needed with different sizes and shapes of silver nanoparticles.

---

Nanoparticles are dispersed droplets or solid particles with a size of 10-100nm which are made in different shapes. Nanoparticles have received more attention as antiparasitic drugs in recent years since current antiparasitic drugs have some side effects and their efficacy is not proved yet. Nanoparticles are currently used in cancer treatment and gold and silver nanoparticles have a long history in the treatment of rheumatoid arthritis. However, far too little attention has been paid to the potential use of gold derivatives against parasitic diseases. In this paper recent developments in the use of gold nanoparticles as anti-parasitic drugs, with emphasis on the major tropical diseases such as Malaria, Leishmaniasis, Schistosomiasis and Trypanosomiasis are reviewed. These diseases affect millions of people worldwide and are involved with many limitations in treatment methods. Some researches indicate that silver nanoparticles, gold, chitosan, and oxidized metals have growth inhibitory or cytotoxic effect on various parasites, including Giardia, Leishmania, Malaria, Toxoplasma and insect larva. Some studies also evaluated the health effects of nanoparticles, such as gold and silver on particular protozoa specially Leishmania and Malaria. Nanoparticles could be used against parasites individually or in combination. Therefore, nanoparticles are recommended for destroying parasites (cytotoxic and inhibitory effect), making more effective and less harmful drugs and also beneficial vaccines for the prevention and control of the parasites.

---

Background and purpose: In the last step of preparation of nanoparticles, glutaraldehyde (GA) is added to stabilize the formed nanoparticles. There are several reports indicating the harmful effects of glutaraldehyde on different organ systems and tissues. The aim of this study was to evaluate the effects of different cross-linking methods like using ultraviolet (UV) irradiation, glucose and combination of these methods on nanoparticles. Materials and methods: Nanoparticles were prepared by desolvation method and in the last step were cross-linked by four different methods. Nanoparticles were compared with each other based on properties like size, zeta potential [by Photon correlation spectroscopy (PCS)], Fourier transform infrared spectroscopy (FTIR), scanning electron micrograph, cellular uptake and toxicity. Results: All nanoparticles had the same range of size (100-200 nm) and only the zetapotential of UV treated group had significant difference with glutaraldehyde group. The results of scanning electron micrograph and FTIR assay were the same for all groups. Cross-linking by combination of UV and glucose had less toxic effects and more viable cells (76.59 ± 7.67 percent) compared to glutaraldehyde (40.08 ± 6.60 percent) (P < 0.01). Cellular uptake of nanoparticles cross-linked with UV and glucose and glutaraldehyde showed similar results. Conclusion: These findings support the idea that using combination of UV and glucose as cross-linking method can be an appropriate alternative method for toxic glutaraldehyde with less toxic effects.

---

Background and purpose: Removal of lead as a toxic metal from contaminated water resources is necessary due to the dangerous effect of lead. One of the most effective methods of removal is the adsorption process. The aim of this study was adsorption and magnetic separation of lead from synthetic wastewater using iron oxide nanoparticles and carbon (ION/C) composite Material and Methods: In this study nanoparticles of iron oxide (ION) were used as a source of iron for magnetic separation of powder activated carbon from solution samples. The physical and surface properties of the adsorbent were studied along with influencing factors (pH, contact time, adsorbent dosage, initial lead concentration, and temperature) on the adsorption process. Kinetic equations and equilibrium isotherms studies were also conducted. Results: The size of ION and specific surface area of ION/C were found to be 30-80 nm and 671.2 m2/g, respectively. We observed that the adsorption process reached equilibrium at 60 min and pH=6and adsorption efficiency increased by increasing the amount of adsorbent and temperature. Maximum adsorption capacity based on Langmuir isotherms was obtained 67.1mg/g at 50 °C. Conclusion: According to this study it is believed that magnetized active carbon by keeping its physical and surface properties could be a suitable method to solve some related problems including separation and filtration.

---

Abstract Background and purpose: Bisphenol A is a harmful organic compound which is either used or produced in various industries. This compound is resistant to biodegradation. The aim of this study was to determine the photocatalytic degradation of Bisphenol A from aqueous solutions by ZnO nanoparticles. Material and methods: In this experimental study the morphology of nanoparticles was characterized using scanning electron microscope. The volume of sample was determined by Rotatable inscribed Central Composite design (CCD) method. The samples were separately placed under UV radiation in defined amount of nanoparticles and initial concentration of bisphenol A at different operating conditions. The concentrations of bisphenol A were analyzed by UV Spectrophotometer. Data was then analyzed in Minitab V.16. Results: The degradation efficiency of bisphenol A increased when the pH, contact time and loading nanoparticles increased and the concentration of bisphenol decreased. Efficiency of ZnO was found to be better at alkaline pH than acidic conditions. UV/ZnO process was capable of removing bisphenol A to 97%. Conclusion: This study showed that photocatalytic degradation by ZnO nanoparticles in presence of UV is an effective method for removal of bisphenol A.

---

Background and Objectives: Humic substances belong to a group of micro molecular of organic substance with different molecular weight produced by reaction of biological and geochemical process. They are known as one of the main prefabrications of disinfection byproducts. This study aimed at investigating the efficacy of (ZnO) nanoparticle under UV/ZnO radiation in removing humic acid. Material and Methods: This study was conducted under laboratory condition. An interval reactor was used to eliminate humic acid by (ZnO) nanoparticle and UV lamp (125 W Philips HPLN). The humic acid was considered in 2, 5, 7 and 10 mg/lit concentrations. To measure the residue of humic acid after radiation of photo Photocatalytic, Spectrophotometer model (UV/VIS Lambda 25 Perkin Elmer, Shelton) was used. Results: The results showed a decrease in efficiency rate when humic acid concentration and pH increased. By increasing the time of photocatalytic activity the removal effect increased. Also, we observed that single-step process and two-step process with higher removal efficiency at Zno concentration of 0.2 mg/l and 0.5 mg/l, respectively. The two-step process was found more capable of removing humic acid with 98.95% efficiency at the concentration of 0.5 mg/l ZnO, detention time of 30min, and at pH 4. Conclusion: This study suggests the use of UV/ZnO process as a suitable method in removing humic acid from aqueous solutions.

---

Abstract Background and purpose: Increasing industrial activities and the subsequent discharge of untreated wastewater containing dye to aqueous environment can cause problems such as reducing the sun light penetration, creating anaerobic conditions, allergy and cancer. Adsorption is considered as one of the most efficient and effective methods for dye removal. The aim of this study was to magnetize the activated carbon with zero-valent iron and using it as an adsorbent for dye removal from aqueous solution. Materials and methods: In this study, co-precipitation method was used for synthesizing magnetic zero valent iron-activated carbon nanocomposite. Characteristics of absorbent were analyzed by SEM, TEM, EDX, XRD, and VSM techniques. We evaluated the effect of independent variables including contact time, solution pH, temperature, adsorbent dosage and the concentration of dyes on response performance (removal efficiency of Basic Violet dye) with response to surface methodology based on box-behnken design. ANOVA was applied to analyze the responses. Results: The optimum conditions for basic violet 16 dyes removal were obtained at pH= 3, contact time= 65 min, absorbent dose= 2 g/L and temperature= 45 C°. Investigating the isotherm and kinetic models showed that the experimental data were correlated with Langmuir adsorption isotherm model (R2>0.995) and pseudo-second order kinetic (R2>0.931). Conclusion: In optimal conditions, magnetic zero valent iron-activated carbon nanocomposite has the potential to remove violet 16 dyes. Also, its separation from the solution is more simple and faster due to its magnetism property.

---

Background and purpose: In MRI the concentration of contrast agent is indirectly measured from signal intensity (SI). It is important to find the maximum linear relationship between SI and concentration of the iron oxide nanoparticles for perfusion measurement. The aim of this study was to investigate the effect of inversion time on SI and the maximum linear relationship between SI and concentration of the polyethylene glycol (PEG) coated iron oxide nanoparticles at different inversion times (TIs) using inversion recovery pulse sequence in T1-weighted MR images. Materials and methods: A phantom was designed to hold the vials with different concentrations of the PEG coated iron oxide nanoparticles in MRI coil. MR imaging was performed using inversion recovery Turbo-FLASH sequence with different TIs. The maximum SI and the maximum linear relationship between SI and concentration of the nanoparticles were measured at different TIs. Results: The maximum SI and the maximum linear relationship between SI and nanoparticles’ concentration were dependent on TI. The maximum SI at different TIs was seen at the highest concentration (500µmolFe/L). The maximum SI which led to a linear relationship with the nanoparticles concentration (R2=0.99) was obtained up to 105.49 and 243.64µmolFe/L for TIs of 400 and 240ms, respectively. Conclusion: TI has an effect on strength of SI in MRI. Increasing the TI values leads to a decrease in concentration of the PEG coated iron oxide nanoparticles that gives the maximum linear SI.

---

Background and purpose: Contamination of drinking water with fluoride due to natural and human activities is a serious problem that threatens human health. Long-term and excessive consumption of water containing fluoride could lead to endocrine glands diseases and Alzheimer's disease. Adsorption process is an effective and popular method for removal of fluoride, so the purpose of this research was magnetizing multiwall carbon nanotubes with nano iron oxide and using it as an adsorbent for fluoride removal from aqueous solution. Materials and methods: Co-precipitation method used for synthesized magnetic nano composite and its characteristics were investigated by SEM, TEM, XRD and VSM techniques. The effect of independent variables such as contact time, pH, temperature, adsorbent dose and initial concentration on fluoride removal was analyzed by response surface methodology (box-Behnken design method) and ANOVA. Results: The optimum condition was obtained at pH= 3, 2g/L sorbent dosage in 2h contact time and 45oC temperature. Isotherms and kinetics results showed that the Langmuir model and pseudo-second order were correlated by data with R2>0.98 and R2>0.941, respectively. Thermodynamic values revealed that fluoride adsorption process was endothermic and spontaneous. Conclusion: In this study synthesized adsorbent was found efficient in fluoride removal (98.5% adsorption in optimal condition) and due to magnetic ability it can be easily separated from the samples by an external magnet. Therefore, it can be applied in removal of fluoride from drinking water.

---

Abstract Background and purpose: Clostridium botulinum neurotoxins are the most potent toxins that cause the life-threatening botulism syndrome in humans and animals. Researches have shown that the binding domain of the botulinum neurotoxin type E has a high immunogenicity effect that could be used as an efficient recombinant vaccine. The recombinant vaccines are not potent enough to stimulate the immune responses, therefore, the use of biocompatible and safe adjuvants is inevitable. In recent years, there have been many studies on the adjuvanticity effect of nanoparticles and their role as delivery vehicles of recombinant vaccines. This study investigated the vaccine delivery effect of chitosan nanoparticles for administration of a recombinant candidate vaccine against Clostridium botulinum type E. Materials and methods: The expression and purification of botulinum neurotoxin type E was done in E. coli BL21 (DE3). Chitosan nanoparticles were synthesized by ionic gelation method. The protein containing nanoparticles were administered to mice subcutaneously. At the same time, a control group received the candidate vaccine in combination with the Freund adjuvant. Finally, the IgG titers of immunized mice were assayed by ELISA. Results: The recombinant protein was successfully expressed and purified and was subsequently confirmed by western blot analysis. The loading capacity of the recombinant antigen into nanocapsules was calculated as 90%. ELISA results showed an increase in the IgG titer after each administration. Conclusion: The present study shows that the chitosan nanoparticles containing a recombinant vaccine could efficiently stimulate the humoral immune responses.

---

Background and purpose: Despite the widespread use of silver nanoparticles, there are concerns about their biological effects on the environment and human health. The aim of this study was to investigate the cytotoxic effect of Ag+ nanoparticles on liver tissue and enzyme activities in NMRI mice. Materials and methods: In this experimental study, thirty five female NMRI mice were randomly divided into one control group and four experimental groups (n=7). The experimental mice, silver nanoparticles at concentrations of 50, 100, 200 and 400 mg kg were injected intraperitoneally (Every other day). Blood samples were taken from the inner corners of the eyes of mice and after separating the serum, liver enzyme activities were analyses. At the end of study, all animals were euthanized via cervical dislocation and tissue samples stained with hematoxylin and eosin for histopathology evaluation. Statistical analysis was performed using SAS software (P≤0.05) Results: Histopathological examination showed that different concentrations of Ag+ nanoparticles cause mild to severe injury (necrosis, inflammatory cell infiltration, and vacuolar degeneration) of the liver. The results showed that the activity of liver enzymes compared to the control group in all groups at a concentration of 400 mg/kg significantly (P≤0.05) increased. Conclusion: Our findings indicated that exposure to the different concentrations of Ag+ nanoparticles can cause severe damages in the mice's liver and increase of serum enzyme activities.

---

Background and purpose: The use of nanotechnology is increasing in different fields of medical sciences including diagnosis and treatment. Metal nanoparticles such as Iron nanoparticles are proposed as novel radiation-sensitizing agents in enhancing the efficiency of radiotherapy because they have a large number of atoms. This study aimed at investigating the radiosensitivity effect of dextran-coated iron oxide nanoparticles on irradiated cervical cancerous HeLa cell line using 6MV photon beams.

Materials and methods: In this experimental study, the cytotoxicity of the nanoparticles on the HeLa cells was measured using MTT assay. To investigate the radiosensitivity effect of the nanoparticles, the cells were incubated with these nanoparticles at 20 and 50µg/ml concentrations and irradiated with different doses of 6MVphoton beams.

Results: The incubation times of 6, 12 and 24 hours at concentrations of 20 and 50µg/ml of nanoparticles on the cells did not show significant cytotoxicity. According to the results, dextran-coated iron oxide nanoparticles showed more radiosensitivity effect at 50µg/ml concentration compared to 20µg/ml. The mean values of dose enhancement factors using 6MV photon beams were 1.19±0.15 and 1.49±0.11, at 20 and 50µg/ml concentrations, respectively.

Conclusion: Dextran-coated iron oxide nanoparticles can significantly enhance the radiation absorbed dose and consequently increase radiotherapy efficiency in cervical cancer cells irradiated with mega voltage photon beam and this could be considered in treatment of cancer.

---

Background and purpose: Magnetite hydroxyapatite (m-Hap) as a magnetic nano-adsorbent was synthesized for the removal of tetracycline (TC) from aqueous solutions.

Materials and methods: The properties of m-Hap were investigated by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). Factors affecting the adsorption of TC including pH (3-10), adsorbent dosage (0.1-5 g/L), contact time (5-120 min) and initial concentration of TC (10-25 mg/L) were investigated. The effect of adsorbent on the removal of tetracycline from real wastewater was also studied.

Results: The nanocomposite was almost spherical in shape and about 20-30 nm in diameter. In optimum conditions more than 99% of TC was removed (contact time 60 min, adsorbent dose 1g/L, and pH 7.5). The equilibrium data were well fitted into Langmuir model (R²= 0.977) and the maximum adsorption capacity was 64.4 mg g^-1 at pH 7.5 and 298 K. Adsorption experiments on hospital wastewater indicated a slight decrease in adsorption removal of TC (85%).

Conclusion: This study showed that the magnetic Hydroxyapatite nanoparticles could be used as a highly efficient and promising adsorbent in water and wastewater treatment systems. 

---

Background and purpose: Aniline is widely used as raw material in many chemical industries. The aim of this study was to survey the photocatalytic degradation of aniline using magnesium oxide nanoparticles from aqueous solutions.

Materials and methods: An experimental study was carried out in a 2 L volume batch reactor. Various parameters such as pH (3-11), dose of nanoparticles (0.1-1), contact time (15-120 min), initial aniline concentration (5-250 mg/L) and irradiation source power (8, 15 and 30 W) were investigated. The concentration of residual aniline was measured by UV spectrophotometer at λ_max of 198 nm.

Results: The results showed that photocatalytic process of nMgO+UV could effectively remove aniline from effluent. The optimal solution pH and dose of nanoparticles for 8 W, 15 W and 30 W UVA lamp were 7.0 and 0.6 g/L, 7 and 0.4 g/L, and 7 and 0.4 g/L, respectively. In 30 min optimum contact time the photocatalytic degradation efficiency decreased when the concentration of aniline was increased. In optimum conditions (5 mg/L of aniline and 30 min reaction time) the aniline removal efficiency was 90.63 % and COD removal was 87.02%.

Conclusion: The photocatalytic process of nMgO+UV can be used as a suitable technique for aniline removal from aqueous solutions.

---

Background and purpose: Dyes from textile industry are amongst the major pollutants of the environment that are harmful for both human health and the environment. Azo dyes constitute the largest and the most important class of commercial dyes, accounting for 50% of all commercial dyes. This study investigated the efficacy of Cr-doped ZnO nanoparticles in removal of reactive black 5 (RB5) dye from aquatic solutions in presence of solar radiation.

Materials and methods: An experimental laboratory study was done by designing the surface-answer test. Cr-doped ZnO nanoparticles were synthesized using co-precipitation method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for characterization of the nanoparticles prepared. Effects of parameters such as pH, nanoparticle dosage, initial RB5 concentration, and contact time on the removal efficiency of RB5 were studied. The remaining concentration of RB5 was analyzed by UV/VIS spectrophotometer at a wavelength of 597 nm. Finally, the statistical analysis of the model was conducted by ANOVA.

Results: Results showed that removal efficiency increased by increasing nanoparticle dosage and contact time. Also, we found that removal efficiency decreased by increasing the initial dye concentration and pH. The optimum condition for dye removal was obtained at pH 4, nanoparticle dosage of 1.75 g/L, initial dye content of 112.5 mg/L, and 75 min contact time. In this condition the efficiency removal and desirability were 75.41 and of 0.905, respectively.

Conclusion: Removal of textile dyes was found to be quick and effective when using Cr-doped ZnO nanoparticles. Also, designing and performing the experiment (in low frequency) can help in optimizing the efficiency removal of pollutant from aqueous media.

---

Background and purpose: Various contaminants are released into water resources each year as a results of urbanization and industrialization. Chromium VI is one of the most toxic metals released into the aquatic environments, wastewater, and soil mainly via industrial sewage. The purpose of this study was to evaluate the performance of iron-zirconium/chitosan magnetic nanoparticles composite in removal of hexavalent chromium VI from aquatic environments.

Materials and methods: A pilot-study was conducted in laboratory scale. Nancomposites synthesis was done using chemical precipitation and tested by SEM, XRD, and FTIR. Various factors such as contact time (0-720 min), initial pH of the solution (2-12), adsorbent dose (0.4-2 gr), initial concentration of metal (0-10 milligrams per liter), and the system temperature (15-35 ℃) were studied. The concentration of heavy metal chromium was measured using a spectrophotometer at 540nm.

Results: The results showed that the highest removal efficiency of heavy metal chromium was obtained at pH 4.0 (52.99%). Moreover, addition of 1 gr composite in the same concentration could boost removing the hexavalent chromium by more than 91%. Increasing the concentration levels of heavy metals had little impact on the removal efficiency. Adsorption isotherms fitted the Freundlich isotherm.

Conclusion: According to the results, the absorbent showed a high performance in removing chromium VI from aquatic environments.