Characterization studies on surface activation of phosphor bronze wire mesh via different chemical means for water distillation applications

Abstract

Surface activation of phosphor bronze structured packing modules is an important step in the manufacturing of high efficiency water distillation columns as it ensures excellent mass transfer behaviour and overall process intensification. These packed columns are used in the nuclear industry for heavy water production and purification. Activation is generally achieved through a treatment involving aqueous NaOH solution with bubbling of oxygen gas through it. This leads to the development of black metal oxide films on the metal packing surface and that improves its wetting behaviour significantly. This work explores some aspects of the development of an alternative activation procedure using NaOH solution with NaClO 2 as the oxidising agent in the solution phase itself. The samples and the spent activation liquids are characterised comprehensively to understand the physico-chemical aspects of the activation process. From the preliminary laboratory scale activation studies carried out so far with phosphor bronze wire mesh coupons, it appears that this two-phase reaction process certainly has the potential to be a faster, less energy intensive and more environmentally benign operation compared with the existing three phase reaction-based method. Keywords: Nuclear Industry, Phosphor Bronze, Heavy Water, Isotropic Purity, Nuclear Reactors