Preparation of carbamate-containing vaterite particles for strontium removal in wastewater treatment

Abstract

Submicron-sized particles of vaterite, containing carbamate-functionalised siloxane (V–Si), were prepared as the precipitant of radioactive strontium in the treatment of wastewater. The particles consisted of 10–22 nm-sized vaterite crystallites with preferred-orientation towards (00l) plane; a highly charged plane. The crystallites were suggested to be stabilised by the coordination of the siloxane through carbamate (NH–COO−) groups. On being soaked in the aqueous strontium chloride solution, vaterite was dissolved from V–Si to facilitate the competitive precipitation of calcian-strontianite and calcite. The particles containing a large amount of silicon exhibited the highly-controlled dissolution; the formation of calcite was suppressed to increase the strontium contents in the resulting precipitates.