Water purification in a fluidized bed photocatalytic reactor using TiO2-coated ceramic particles

TiO2-coated mm-size spherical ceramic particles which are very stable for dynamical impact and whose specific density is very near to unity were developed and applied to a fluidized bed reactor for water purification. Two types of test-scale fluidized bed photocatalytic reactors were prepared: the reactor a which holds the ultra violet light source (254 nm) inside it and the reactor b which holds the light source (365 nm) outside it. The latter one is supposed to be operated under solar light. Phenol and bisphenol A were selected for target contaminants and the decomposition experiments by fluidized bed photocatalytic reactor were conducted. It was shown with the reactor a that aqueous phenol and bisphenol A with 10 mg/dm3 in 2 L water can be decomposed rapidly in about 200 min and TOC originated from their byproducts can eventually be mineralized in short time in 300 min. It was also shown through the decomposition experiment using the reactor b that water purification under solar light can be possible, though the decomposability is less effective: it took about 20 h to mineralize the aqueous contaminants with10 mg/dm3 in 1 L water.