Procedure and device for treatment of water with ozone to remove metal ions - measurement of ozone content of treated water before filtration is used to adjust ozone content by controlled dosing with raw water

摘要

Procedure for treating water with ozone has treated water stream (12) dosed with additional ozone-consuming raw water at a rate determined by the required residual ozone content level upstream of the filter (18). The residual ozone level is chosen so that at the end of the filtration process the ozone content of the water has been fully consumed and the product water is completely free of ozone. The residual ozone content of the water before filtration and downstream of the dosing point is continuously measured. The ozone content of the water may be measured indirectly from the ozone content of a gas or air stream passed in contra-flow through the water or passed over the surface of the water. The treated water is pref. passed through a static mixer (32) after dosing and before measuring the residual ozone content. USE/ADVANTAGE - Used in the preparation table waters and mineralised waters, in which ozone is used to convert substances such as heavy metals (e.g. iron, manganese), to a form which can be removed by filtration. The effectiveness of the process is improved so that activated-carbon filtration is unnecessary.