ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY https://doi.org/10.14233/ajchem.2017.20827 INTRODUCTION Dyes are main contributor of water pollution in many industries such as paper, leather, textile etc. The removal of dyes from the polluted water is one the matter of most concern. This is because most of dyes are toxic, carcinogenic and mutagenic in nature and the removal of such dyes from aquatic systems is extremely important from the environmental view point. Mostly dyes are organic compounds having aromatic complex structure and difficult to remove from polluted water [1,2]. From last four decades, different techniques such as coagulation, advance oxidation, membrane filtration, reverse osmosis and adsorption [3-8] have been used to remove dyes from polluted water. Literature studies reveal that among these methods adsorption technique is one of most convenient technique for the removal of dyes from waste water. Adsorption method has various advantages over the conventional methods such as simple, low cost and less land involvement [7,8]. In adsorption process various types of natural and synthetic adsorbents such as activated carbon, clay, clay minerals, rice husk, saw dust, etc. [9-16] have been used as natural and synthetic adsorbents for waste water treatment. From last two Synthesis of Spinel ZnFe 2 O 4 Modified with SDS via Low Temperature Combustion Method and Adsorption Behaviour of Crystal Violet Dye MUKESH KUMAR, HARMANJIT SINGH DOSANJH and HARMINDER SINGH * Department of Chemistry, School of Physical Sciences, Lovely Professional University, Phagwara-144 411, India *Corresponding author: Tel: +91 18 24444307; E-mail: harminder.singh@lpu.co.in; harminder_env@yahoo.com Received: 15 April 2017; Accepted: 30 May 2017; Published online: 15 July 2017; AJC-18491 Nano materials such as nano ferrites and their composites have been intensively investigated for water treatment. In present study nano zinc ferrites were successfully synthesized using low temperature combustion method and the surface of nano zinc ferrite was modified with surfactant sodium dodecyl sulphate (SDS). The characterization and morphology of zinc ferrite have been studied by FTIR, SEM and XRD techniques. Sodium dodecyl sulphate modified zinc ferrite showed excellent adsorption behaviour toward crystal violet dye. The adsorption behaviour has been studied at various parameters such as pH, adsorbent dose, temperature, concentration and time. The experimental data obtained from adsorption studies have been analyzed by Langmuir, Freundlich, Temkin and D-R adsorption isotherm models at different temperatures. The data was well fitted in Langmuir isotherm model. The maximum adsorption capacity (Qo) at different temperatures as 298, 303 and 308 K were 135.5, 170.6 and 188.3 mg/g. The adsorption kinetics was studied by using pseudo first order, pseudo second order and intra particle diffusion model. The adsorption kinetics was found to follow the pseudo second order kinetic model. Adsorption thermodynamic parameters ΔG°, ΔH°and ΔS° have been calculated from experimental data and indicated that the adsorption process was spontaneous in nature. The results showed that SDS-Zn ferrites as a magnetic adsorbent might be a suitable alternative to remove dyes from waste water. Keywords: Spinel Zn ferrite, Low temperature combustion method, Surface modification, Adsorption Kinetics, Adsorption isotherm. Asian Journal of Chemistry; Vol. 29, No. 9 (2017), 2057-2064 decades, the use of nano particles in adsorption field is getting more interest. Literature studies indicate that nano materials have high adsorption capacity [17-23] in comparison to traditional adsorbents and can be prove as an excellent adsor- bent to remove dyes from waste water. However, being smaller in size and such particles cannot be recovered efficiently from treated water by using traditional methods such as filtration, sedimentation etc. The use of magnetic nano ferrites as adsorbent in waste water treatment can overcome the problems and be readily separated from treated water by applying external magnetic field. Nano ferrites have high adsorption capacity to remove dyes from waste water [24-28]. These types of nano particles have highly reactive surface with less stability in general environmental conditions. Therefore various surface modification techniques like doping of metal/metal oxides, polymer coating and surfactant coating have used to modify the surface of nanoferrites [29]. Recent studies revealed that the surface modified nano ferrites have high stability and adsorption capacity to remove dyes from waste water [30-49]. Surface modification is essential need to enhance the adsor- ption capacity and stability of nano ferrites. In present study, magnetically separable nano zinc ferrites (ZFN) was synthesized