Using nano-particles of the tire ash to produce Zn-nutrient solution for hydroponics system

The disposal of solid residues from human activity is a growing environmental problem. One such residue is scrap tires, which are non-biodegradable. Nowadays, the uncontrolled dumped of used tires is of great environmental concern [5]. Therefore, other approaches of tirediscarding or recycling have to be considered. Because of their high heat content and low levels of moisture and nitrogen compared to coal, tires are ideally suited for energy recovery through combustion [2, 4]. The EPA has shown that tire produces emissions comparable to other conventional fuels. At well controlled facilities, emissions will not change significantly when tire is used to replace some of the typical fuel used at the facility [3].In many cases, the ash produced during tire combustion causes some environmental and economical problems. Considering the high amount of zinc oxide in the tire, the ash produced during tire burning contains high concentration of Zn. The average value of ZnO in car and truck tires are 1.2% (with a range of 0.4 to 2.9%) and 2.1% (with a range of 1.2 to 4.3%), respectively [1, 4, 6]. Zinc is a necessary nutrient for plant growth that its deficiency is widespread in different crop cultivation systems. Regarding that zinc fertilization is a common practice to overcome Zn deficiency, finding some effective and non-expensive sources of Zn is of great importance.Therefore, the aim of this study was to investigate the possibility of using nano-particles of tire ash as a source of micronutrient zinc in tomato hydroponics culture [4].