Vol.:(0123456789) 1 3 Model. Earth Syst. Environ. (2017) 3:38 DOI 10.1007/s40808-017-0284-1 ORIGINAL ARTICLE Adsorption of malachite green and methyl orange onto waste tyre activated carbon using batch and fxed-bed techniques: isotherm and kinetics modeling Tabrez A. Khan 1  · Rumana Rahman 1  · Equbal A. Khan 2   Received: 23 July 2016 / Accepted: 3 February 2017 © Springer International Publishing Switzerland 2017 Keywords Adsorption · Waste tyre activated carbon · Dyes · Isotherms · Kinetics · Modeling · Fixed-bed Introduction The decolourization of textile dye-containing wastewater is of utmost environmental concern in view of the non-bio- degradable, recalcitrant and harmful nature of most of the dyes. Among various treatment processes such as electro- coagulation (Ali et al. 2012), advanced oxidation processes (Karthikeyan et al. 2012), photo-degradation (Saleh and Gupta 2012), adsorption technique is highly efcient for treating aqueous efuents containing dyes/metals (Gupta et al. 2012; Khan et al. 2016a, 2015a, b; Khan and Singh 2010). Activated carbon has been employed as an adsor- bent for the removal of variety of pollutants including dyes and metal ions from aqueous solution owing largely to its high surface area (800–1500 m 2 /g), internal porous struc- ture, and varying surface functional groups. However, the expensive commercial activated carbon has limited appli- cability in wastewater treatment for economic considera- tion. Resultantly, activated carbons derived from various abundant, renewable and low cost agro-waste materials such as peanut sticks wood (Ghaedi et al. 2014a), pineap- ple waste (Mahamad et al. 2015), deoiled linseed cake (Khan et al. 2016b), Acacia fumosa seed shell (Kumar and Tamilarasan 2013), cotton stalk (Deng et al. 2009), rice husk (Sharma et al. 2011) and fnger-citron-residue (Gong et al. 2013) were utilized for the removal of dyes from water. The disposal of discarded rubber tyres, being non-biodegradable, pose formidable waste management problem. With the phenomenal increase in the number of vehicles the annual waste tyre generation (97 million) may increase gradually (Urban Waste Profle 2010). Converting Abstract The adsorption of malachite green (MG) and methyl orange (MO) from aqueous solution by waste tyre- derived activated carbon (WTAC) using in batch and fxed- bed column methods was studied. Freundlich model with high correlation coefcient (0.99) described the adsorption data more suitably than other models, indicating multi-layer adsorption of dyes onto heterogeneous WTAC surface. The maximum Langmuir monolayer adsorption capacity was 29.23 g/kg for MG and 13.56 g/kg for MO. The adsorption obeyed pseudo-second order model, following both flm- difusion as well as intra-particle difusion mechanisms. The thermodynamic parameters indicated spontaneous and endothermic adsorption. Fixed-bed column studies at vary- ing fow rates between 3–5 mL/min for MG and 2–3 mL/ min for MO, initial dye concentration (40–50 mg/L), and bed heights (1–2 cm) indicated that breakthrough time and exhaustion time increased with decreasing fow rate, increasing bed height and decreasing initial dyes concen- tration. The experimental data ftted well with Thomas and Adams–Bohart models with maximum Thomas model adsorption capacity of 71.71 g/kg for MG and 6.86 g/kg for MO. Thus, WTAC proved a promising adsorbent for the removal of MG and MO from aqueous solution. Electronic supplementary material The online version of this article (doi:10.1007/s40808-017-0284-1) contains supplementary material, which is available to authorized users. * Tabrez A. Khan takhan501@yahoo.com 1 Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi 110 025, India 2 Department of Chemistry, Al Falah University, Dhauj, Faridabad, Haryana 121004, India