Production of floating photocatalytic composite particles by membrane emulsification and pickering emulsion methods and evaluation of their photocatalytic activity

In this thesis, floating photocatalytic particles were produced by membrane emulsification and Pickering emulsion methods, which are methods being attractive recently with the ability to produce particles of homogenous size distribution and enhanced stability compared to conventional emulsification methods, in order to increase photocatalytic efficiency of TiO2 particles in wastewater treatment and to minimize their disadvantages. For assessment of photocatalytic activities of composite particles coated with TiO2 nanoparticles, a herbicide with endocrine disrupting effects called atrazine was chosen as model contaminant, and effects of parameters such as type of photocatalyst, amount of TiO2, initial organic pollutant concentration, pH, and stirring on photodegradation of atrazine were studied. A TiO2 based floating composite photocatalyst was successfully produced with membrane emulsification and Pickering emulsion methods with a particle size of 110 µm when the core phase was introduced as oleic acid. At optimum conditions, the composite particles were able to remove atrazine from water up to 97% with relatively high reaction rates. When the surface was covered at higher degrees, the degradation of atrazine was improved. As selected initial atrazine concentration and amount of composite catalyst used were increased, higher reaction rate constants were obtained. Photodegradation efficiency at strongly acidic pH value of 1.90 is found to be higher compared to strongly basic pH of 9.30.