Medicine removal from wastewater by using photocatalysis method

Abstract

Water pollution is a global problem that has become very important. Overcoming water pollution and keeping water resources clean has become a basic need. For this reason, studies on the removal of pollutants from wastewater have gained momentum. Photodegradation is a method used to remove harmful pollutants from wastewater. The synthesis of photocatalysts suitable for this purpose is of great importance. There are studies where Graphene Oxide (GO)-Hydroxyapatite (HAp) (GO-HAp composite) is used in the removal of different materials from wastewater. Due to the fact that GO is easily miscible with different materials, reduces the band gap of the material to which it is added, and has an effect on conductivity, it can be used in different ways to remove pollutants from wastewater. It is widely used in the preparation of composites with other materials. HAp is an ideal material preferred for environmental improvement due to its high specific surface area and stability. Especially in recent years, studies have been carried out on the use of HAp alone or in combination with other photocatalytic materials. In this study, GO-HAp composite was synthesized and its use as a catalyst in the process of removing tetracycline from wastewater by photodegradation was investigated. The aim of this study is to determine the optimum conditions for the removal process of tetracycline. For this purpose, the parameters of pH, initial drug concentration and amount of catalyst used were selected and experiments were planned and carried out according to the "Box-Behnken" design, which is one of the experimental design methods. According to this design, the effects of the selected parameters on the process are also revealed. In the experiments, 50 mL of the drug solution prepared at the initial concentration and pH determined in the design was taken and then the amount of catalyst determined in the design was added into it. Experiments were carried out under continuous stirring for the first half hour in the dark to reach the adsorption equilibrium, followed by visible light. The concentration of tetracycline was followed for 3 hours by UV-spectrophotometer by taking samples from the environment at certain intervals and the percentage of removal for tetracycline was calculated. Removal percentage results obtained were evaluated with "Box-Behnken" using Minitab program. As a result of the experiments, it was decided that the GO-HAp composite was a suitable catalyst for the removal of tetracycline from wastewater by photodegradation and optimum conditions were determined.