Preventing the growth of iron bacteria in water wells by copper and silver coating

The growth of iron-related bacteria and their deposition of iron oxides often impedes the operation of water wells, resulting in costly rehabilitation measures. The microbicidal potential of a silver and copper coating was investigated. Field-scale experiments on a riser pipe showed that silver coating only slightly subdued the growth of iron bacteria, while copper coating was highly effective. However, the coating was eroded and oxidized over the course of the experiment, rendering it ineffective. Model experiments with different types of copper coatings showed that only polished copper metal was able to prevent the growth of an iron bacteria biofilm for a longer period of time, while thinner coatings were overcome after some months. While the coating of screens, casings and riser pipes might thus not be sustainable, protecting parts of the submersible pump prone to iron oxide deposition by a copper coating could be an interesting option.