© Authors. Terms and conditions of Creative Commons Attribution 4.0 International (CC BY 4.0) apply. alirizakul@yyu.edu.tr skeskin973@gmail.com canantasin@gmail.com (*Correspondence) salihalkan@ordu.edu.tr OPEN ACCESS Eurasian Journal of Analytical Chemistry ISSN: 1306-3057 2018 13(2):em09 DOI: 10.12973/ejac/80992 Statistical Modeling of Cobalt Adsorption on Van Pumice Ali Rıza Kul 1 , Sıddık Keskin 2 , Canan Demir 1* , Salih Alkan 3 1 Yuzuncu Yıl University, Vocational School of Health Care, Van, TURKEY 2 Yuzuncu Yıl University, Faculty of Medicine, Department of Biostatistics, Van, TURKEY 3 Ordu University, Faculty of Art and Science, Department of Chemistry, Ordu, TURKEY Received 30 July 2017 ▪ Revised 13 November 2017 ▪ Accepted 16 December 2017 ABSTRACT The aim of this study is to statistical modeling of cobalt adsorption on Van Pumice. Van Pumice was used for determination of cobalt adsorption level. Modeling, depending on time, was performed to determine for cobalt adsorption level at fixed pH 5 for various concentration and temperatures in Van pumice. All adsorption measurements were performed with the Thermo Scientific brand ICE spectrometer model 300 Series. One-way analysis of variance was used for comparison to various temperature and concentration levels. Tukey’s multiple comparison test was also performed to determine different groups. Logarithmic, quadratic, Qubic and logistic models as well as linear were used to determine adsorbed cobalt amount at different temperature levels and heavy metal concentration. Differences between various time and temperatures levels were found statistically significant, however, there were no significant differences between time level. R 2 values of the models ranged from 70% to 99%. In addition, cubic model had higher R 2 values for each concentration and temperature levels. Cobalt concentration and amount of ions have been increased in the solution. The performance of all models to determine the amount of adsorption of cobalt has been significantly found. However, model the best performance has been shown with the cubic. Keywords: Co, adsorption, logarithmic, logistic models INTRODUCTION Heavy metals may spread the environment from various sources. The firs one of these resource is daily activities of people. Consumption of solid fuel containing a large amount of heavy metals, exhaust emissions, industrial and household waste as well as mining activities and industrialization are among the main causes of serious heavy metal pollution [1]. Cobalt is solid structure and formed during the production of lead and tin mines that is non- melting and prevents the use of metal. Cobalt is in the least elements group of Earth with 25 mg / ton average value. Cobalt has important applications areas such as military, strategic and industrial. The most using type of cobalt is as super alloys in jet engine turbine. In addition, cobalt is also used to provide the magnetism properties for materials, protect from corrosion, and improve the mechanical properties in alloys, speed steel, tool steel, diamond tools, and cutting edge. Although, there are no certain findings about that cobalt and cobalt compounds cause cancer in humans, it has been noted that these compounds are carcinogen substances [2]. Adsorption is a separation process that is based on transferring of atoms ions or molecules in the solution medium to an adsorbent surface and often occur in the surface phase. Adsorption is described as hold of the atom, ions or molecules on a solid surface. Desorption is expressed as separation of hold particles from the surface. Similarly, solid is called adsorptive (adsorbent) and keep the material on the solid surface is called adsorbed (soluble) [3]. The effect of temperature on the adsorption depends on being of adsorption exothermic or endothermic. Increasing of temperature causes