Views: 0 Author: Site Editor Publish Time: 2022-04-28 Origin: Site
Iron and manganese removal is one of the more common uses of ozone in drinking water systems. Iron and manganese are easily oxidized by ozone. This document will help to understand the rationale for oxidizing iron and manganese with ozone. We'll also cover the practical application of ozone in this application, while providing helpful tips learned over the years.
Ozone, iron oxide and manganese are a very fast reaction. In many ozone applications, because soluble iron and manganese are inadvertently oxidized by ozone and fall out of the solution in an unsatisfactory position, the increase of iron and manganese content will cause trouble. If these problems attract your attention, please continue to read, and we will provide useful tips to alleviate these problems as much as possible.
Iron and manganese in water will not cause health problems because of the discoloration of water. The main purpose of removing iron and manganese is beauty. Iron and manganese may also need to be removed due to the accumulation of iron and manganese on pipes, fixtures and other surfaces.
Both iron Fe (II) and manganese Mn (II) are soluble in water (not removable), resulting in their direct passing through conventional filtration without some form of oxidation, thereby converting them into particles (removable).
Soluble iron Fe (II) is called ferrous. Ferrous Fe (II) is oxidized to ferric Fe (III) by ozone. This ferric Fe (III) is then hydrolyzed to form Fe (OH) 3, which is a particle that can be removed by standard filtration. The reaction between ferrous Fe (II) and iron Fe (II) consumes 0.43mg ozone per mg of Fe (II). Iron can also be oxidized by oxygen. Due to the oxidation of iron by oxygen, the ozone system for iron removal may be more effective, and the calculated ozone demand is 0.43 mg of ozone per mg of iron. The oxidation of ferrous only requires electron exchange, so it is a rapid reaction. Before any manganese oxidation, the rate of this reaction usually consumes almost all ozone in the iron oxidation reaction.
Soluble manganese Mn (II) is oxidized by ozone to form manganese dioxide MnO2, which is a particle and can be easily removed by standard filtration. This method consumes 0.88mg ozone per Mg Mn (II). However, excessive manganese oxide will form soluble permanganate MnO4 -. Although permanganate usually returns to manganese dioxide MnO2 over time (20-30 minutes), it is best to design a manganese removal system with an appropriate ozone dose and integrate controls to prevent excessive oxidation.
Ozone oxidizes iron and manganese to form insoluble particles that can be easily filtered out of water. Over time, iron and manganese will accumulate on the filter and must be removed from the process water. For these applications, backwashable filters are strongly recommended. Sand filters are widely used to remove iron and manganese due to their simple design and durable filter media. In a continuous use system, two (2) filters must be used in parallel and backwash cycles must be performed at opposite times.
These filters contain extremely high levels of iron and backwash water must be handled carefully. Keep in mind that there is no risk of iron or manganese accumulation in the pipeline over time, although there is no risk of iron or manganese accumulation.
Ozone for iron and manganese oxidation can well solve the problems that may be difficult to solve using other technologies. It can be easily implemented and maintained without a large amount of ozone cost. However, if installed improperly, ozone is also difficult to manage. Iron can precipitate out of the solution at unwanted locations, and manganese can be over oxidized and filtered even after ozone treatment. This informative document is intended to provide some useful tips and information. If you think ozone may be a solution for your application, please call our office and contact our application engineer to help you design a solution suitable for you.