Conclusion
In this study, effects of initial phosphate concentration and current density on phosphate removal by electrocoagulation using aluminum and iron plate electrodes were investigated and effects of these parameters on system parameters were analyzed. In the experiments using aluminum electrodes, efficiency of 100% was obtained for all initial phosphate concentrations. Initial phosphate concentrations have effected energy consumptions and reaction rates. But when iron is used as electrode material, removal efficiencies have reduced by increasing initial phosphate concentration. Because of this, reaction rates have decreased by increasing initial phosphate concentration and removal efficiencies are mainly due to pH using iron electrodes. Extension of reaction time has caused excessive increase of pH. Removal rate is very slow over pH 9 approximately. Consequently, if pH is not fixed, it is hard to reach efficiency of 100% in high initial phosphate concentrations using iron electrodes.
Besides, in the experiments, effects of current density on phosphate removal by electrocoagulation were investigated. According to results obtained from the experiments, removal rates and removal efficiencies have increased by increasing current density using either aluminum or iron plate electrodes. But system energy consumptions have increased by increasing current density.
Consequently, it can be said that aluminum electrode is more suitable than iron electrode by taking into account either removal rate and removal efficiencies on phosphate removal by electrocoagulation.
Electrocoagulation is comparatively suitable process for phosphate removal using either aluminum or iron plate electrodes.