Advanced disinfection of ground water and toxicity analysis

In this thesis, water disinfection by electrochemical oxidation was carried out in parallel-plate reactors with iridium-oxide and graphite electrodes, and in trickling tower reactors with ruthenium metal oxide electrodes. In studies with the parallel-plate reactor, batch and continuous systems were set up and the effects of treatment time and applied current density on the survival ratio of E. coli bacteria and on corresponding toxicity were investigated. In continuous system studies, various current densities were applied at different flow rates on a solution with known initial E. coli concentration and their effects on survival ratio was investigated. In trickling tower reactor studies a solution with known initial E. coli concentration was disinfected by electrochemical oxidation by applying electrical potential at various flow rates, and the changes in the survival ratio and toxicity were investigated. Furthermore, water sample from groundwater in Eskişehir was subjected to electrochemical disinfection in both parallel-plate and trickling tower reactors. According to the results, it was observed that, although all types of electrodes successfully disinfect ground water, parallel-plate reactors are more efficient in the process. It was also observed and concluded that toxicity analysis is necessary especially in situations where high concentrations of bacteria within ground water are completely annihilated with electrochemical disinfection.