Complex ions treatment of water supplies systems revealed cost efficient approach to rust removal

摘要

Rust removal from the industrial water supply systems is the major problem of their maintenance. As a consequence of rust accumulation, water mineralization decreases thereby leading to the expedited deterioration and energetic burdening of the system. We assume that the photoprocesses, which take place in the inert films on the iron surface, might have an implication for the development of antirust means. Particularly, the effects of additives on the kinetics of iron dissolving have never been investigated. Following this thought, we studied the absorption of (1) surface-active ions (Ba~2+, Ca~2+, Cl~- N C_6H_5COO~-) on anode-oxidized iron electrode at neutral pH and (2) the complex ion oxyethylen diphosphoric acid (OEDP) on powdered magnetite Fe3O_4 in sulphuric acid. The iron electrode was covered with hydrated oxide γ-Fe2O_3. For the first time Intensity Modulated Photocurrent Spectroscopy (IMPS) has been applied to monitor ion absorption on passivated iron surface. The main advantage of IMPS is that it enables detection when the film capacitivity is much smaller than capacitivity of DES. Anions absorption was found to increase the photocurrent while kations absorption rather decreased one (Fig.1).