Research Journal of Chemical Sciences ______________________________________________ ISSN 2231-606X Vol. 5(12), 38-43, December (2015) Res. J. Chem. Sci. International Science Congress Association 38 Removal of Malachite green dye from Aqueous solution using Magnetic Activated Carbon Jaiswal Rinku1*, Singh Shripal and Pande HemantCIMFR Nagpur Unit-II, 17/C-Telenkhedi area, Civil Lines, Nagpur, 440001, INDIA Hislop college, Civil lines, Nagpur-440001, INDIAAvailable online at: www.isca.in, www.isca.me Received 9th November 2015, revised 26th November 2015, accepted 10th December 2015 AbstractMagnetic activated carbon (MAC) was synthesized by combining aqueous solution of prepared activated carbon (AC) and iron oxide nanoparticles by co-precipitation method. A variety of techniques such as N-BET surface area, X ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the structure,morphology and magnetic performance of MAC. The N-BET surface area of the MAC (721 m-1) is found lesser than the prepared AC (1900 m-1). The saturation magnetization for MAC was 22.80emu/g it shows super magnetic behaviour. SEM of the MAC shows the presence of different size pores, cracks and crevices. TEM of MAC produce nanoparticles with size in the range of 5-25nm. XRD of MAC indicates the presence of crystalline structure for iron oxide nanopartcles. The adsorption data show that the adsorption capacity was investigated by absorbing Malachite Green (MG) from aqueous solution, which demonstrated an excellent adsorption capacity of MAC (333 mg g-). A Langmuir kinetic model is fitted well for malachite green adsorption on MAC. Keywords: Magnetic Activated carbon, chemical co precipitation, Malachite green dye, adsorption and kinetics. Introduction Due to rapid industrialization the removal of dyes from industrial waste water is becoming increasingly important as awareness of the environmental impact of such pollutants is fully realized1,2. In industries, such dyes precipitating out of solution and coating other materials can have a profound effect on both aqueous and nonaqueous environments. Malachite Green (MG) is dye is basically a cationic dye and these dyes are used in many industries for their coloring agent4,5. Activated carbon with high surface area has been widely used in a variety of applications like separation /purification of liquids and gases, removal of toxic substances and organic pollutants from drinking water, recovery of solvents and as catalysts. As environmental pollution is becoming an increasingly serious problem, the need for high surface area activated carbon is growing. It can be prepared from any carbonaceous materials like agriculture waste, coal and ligno-cellulosic materials. Activated carbon is a non graphitic carbonaceous material with high surface area, pore volume and widely used as an adsorbent in chemical and food industry. Most commonly used malachite green dyes removal methods like coagulation, ion exchange, precipitation and adsorption, out of which adsorption is the most widely used because of high efficiency, low cost and easy to handle6-10. Activated carbon is considered to be one of the best technologies implanted in water purification systems11. Many researchers have investigated activated carbon is expensive price, it uses cheap and efficient alternative to remove dyes from waste water treatment12. Recently, magnetic activated carbons have been interested in many researchers and scientists. Nowadays, nanoparticles are not only widely applied in the fields of medicine, molecular biology and bioinorganic chemistry, but they are also well known in environmental science13. Magnetic activated carbon adsorbents can easily be separated from a solution using a magnetic separator even if the solution contains a significant concentration of solids. In contrast, traditional adsorbents are removed by screening. Magnetic materials have gained special attention in water treatment, based on their advantage such as easy separation, simple manipulation process, kind operation conditions and easy specifically functional modifications14-15. The present work is an attempt to prepare magnetic activated carbon (MAC) by using activated carbon and Fe4 magnetic nanoparticlesby a chemical coprecipitation method for the removal of Malachite Green (MG) dyes from aqueous solution. Material and Methods Materials: Nitric acid (HNO3, 63%), Ferric Chloride (FeCl), Ferrous chloride (FeCl), Sodium hydroxide (NaOH) and Malachite green dye (Merck, India) were procured from Nagpur, India. Preparation of Magnetic activated carbon (MAC): The magnetic activated carbon was prepared by combining aqueous solution of prepared activated carbon (AC) and prepared iron oxide nanoparticles Fe by co-precipitation method. First to prepare magnetic iron oxide nanoparticles Fe were carried out in co-precipitation method. A suspension of 20 g FeCl and 10g FeCl per 400ml of deionised water was stirred for 1h. After Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 5(12), 38-43, December (2015) Res. J. Chem. Sci. International Science Congress Association 39 stirring by adding 2M NaOH solution at 40C under the presence of N2 gas. These suspension keep at 70C for 12h. Finally Fe was cooled at room temperature, washed with deionised water until pH neutral. In the next step some amount of Activated carbon were impregnated with nitric acid using ultrasonic bath without stirring for 2 hours at 100C. This impregnated activated carbon was filtered and dried at room temperature. Then Activated carbon mixed with prepared Fe3O4 nanoparticles in 200ml aqueous solution for 1.5 h at 100C. Then these samples were filtered and dehydrated in an oven at 100C for 1h. Then these samples were heated in muffle furnace at 750°C for 3h under the presence of N gas. The product washed with deionised water to remove excess NaOH and dried at 70C. Method for Adsorption Isotherm and Kinetics study: To evaluate adsorption equilibrium data for Malachite Green (MG) experiments were performed in a batch system. 100mL of MG solution of known concentration was placed in 300 ml BOD bottles and accurately 0.1 gm Magnetic activated carbon (MAC) were added into each bottle. The BOD bottles were placed on a mechanical shaker with shaking speed of 600+-20 rpm and stirred for 72 hours. After equilibrium reached, solutions from each bottle were withdrawn and adsorbate concentration, C was determined by UV/visible spectrophotometer (Model Lambda 35, Perkin Elmer UV/VIS spectrophotometer) with wavelength 615 nm. Kinetics study, a cylindrical vessel of 5L capacity fitted with 8 baffles was used. 2gm of accurately weight prepared magnetic activated carbon was introduced into 2L of malachite green solution of known concentration with constant stirring. The adsorbate was taken out from the vessel at following time period and the concentration was determined with the help of UV/visible spectrophotometer. Results and Discussion Characterization of prepared MAC: To determine Microporous structure of the MAC, iodine number was determined as per ASTM D4607-94 (1999) and the surface area and pore volume of prepared MAC were determined by SMARTSORB 92/93 N- BET surface area analyzer. The iodine number of AC; 1650 mg g-1 is more than that of MAC; 670 mg -1and NBET and pore volume of AC are 1900m g 1 , 0.5420 cm g 1 and MAC are 721 m g 1 ,0.3459 cm g 1 respectively shown in Table-1. The lesser surface area of the MAC is due to partially filling of pores of AC with iron oxide nanoparticles. It reveals that magnetization processes reduce the Iodine value, surface area and the pore volume. Micro porosity development is substantially reduced in MAC. Table-1 Characteristics of AC and MAC Adsorbent Iodine number (mg/g) -BETsurface Area (m/g) Pore volume (cm/g) MAC 670 721 0.3459 AC 1650 1900 0.5420 X-ray diffraction (XRD) analyses of prepared magnetic activated carbon sample were carried out with X-ray Diffractometer model (PANalyticalX’pert Pro). XRD patterns are given in figure-1. The XRD pattern shows a crystalline structure and indicates the amorphous character of the carbon matrix in which iron oxide nanoparticles is impregnated. The X-ray diffraction patterns for MAC show a number of sharp peaks which are compatible with the presence of Fe(OH) , Fe(OH)3 and Fe3. The surface morphology of MAC was studied by scanning electron microscopy (SEM) with a JEOL JSM-6380 model Scanning Electron Microscope. Figure-2 shows SEM image of MAC, in the picture it appears that Fe particles composed of small particle. Figure-1 XRD of MAC