Corrosion causes, early accounts

Since the early days of using PVC separators in stationary batteries, there has been a discussion about the generation of harmful substances caused by elevated temperatures or other catalytic influences, a release of chloride ions could occur which, oxidized to perchlorate ions, form soluble lead salts resulting in enhanced positive grid corrosion. Since this effect proceeds by self-acceleration, the surrounding conditions such as temperature and the proneness of alloys to corrosion as well as the quality of the PVC have to be taken carefully into account. 

As we have already emphasised, the sensitivity of PI unit operations to contaminants within process steams - such as particulates causing fouling, blockage or corrosive fluids - so the use of PI for effluent treatment has to take into account the fact that many effluents are, by their nature, foul . Obviously care can be taken in the selection of appropriate components for effluent treatment, and a major opportunity for PI is that it can be used as the basis for compact, reduced capital cost and energy-efficient effluent treatment plant. An early UK case study undertaken in the 1990s illustrates the benefits that could accrue to the use of PI in effluent treatment. 

---