Removal of nitrate onto spent tea leaves and spent coffee grounds in a fixed bed column

Abstract

Water is an important source on the earth and it is the essence of life. In the development of agricultural sector of our nation, fertilizer is used f oor the plant growth and it is important in order to make sure the plant get enough nutrients. However, nitrogen-rich fertilizer such as potassium nitrate can creates pollution through run-off into surface water and leaching into ground wat er. Furthermore, presence of nitrate in drinking water can cause health problems such as cyanosis amongy children and cancer of alimentary canal. Thus, removal of nitrate from contaminated water is significant because it is important for environment and health. The experiments were carried out as a function of contact time and the performance between tea and coffee was compared in a batch operation. The study was conducted in the range of 30 min to 4 hour to investigate the effect of contact time on the adsorbents. Then, the removal of nitrate from water was done by adsorption process and was conducted in a fixed bed column. The bed height and initial nitrate concentration was varied at (4.5 cm to 12 cm) and (100 mg/L to 250 mg/L) respectively. The percentage removal of nitrate was determined for both batch and continuous process. For continuous, breakthrough time was obtained by evaluating the breakthrough curves at different bed height and different initial concentrations and at the optimum pH for adsorption of tea which is pH 6. The best percentage removal of nitrate was obtained at higher bed height and lower initial concentration. The breakthrough time increase as bed height increase and initial concentration decrease.