Removal of nitrate and other anions from water by yellow bismuth hydroxide
In regard to the low solubility of basic bismuth nitrate several bismuth compounds were examined on their ability to remove NOsub3high- from water. Yellow bismuth hydroxide proved to be an effective material for that purpose, removing also POsub4high3-, SOsub4high2- and Clhigh-. The selectivity of the method, which based on ion exchange with OHhigh- as counter ion, depends on the pH-value. Regeneration can be achieved by NaOH. The method is discussed in regard to a possible technical realization especially for the preparation of drinking water.