3.2 Municipal Water Treatment (GAC)

Municipal water treatment plant

The process flow diagram illustrates a municipal water treatment plant that is used for the removal of taste and odour compounds. Water is pumped from the river into a flotation unit, which is used for the removal of suspended solids such as algae and particulate material. Dissolved air is injected under pressure into the basin through special nozzles. This creates microbubbles which become attached to the suspended solids, causing them to float. The result is a layer of suspended solids on the surface of the water, which is removed using a mechanical skimming technique.

Municipal water treatment plant

Ozone is produced on site by passing high tension, high frequency electrical discharges through air in specially designed equipment. Ozone is injected into the water to provide a powerful bactericidal action and to break down the natural humic compounds that are the cause of the taste and odour problem. The water then enters a rapid gravity filtration system filled with Filtracarb® FY5, which is used to adsorb the compounds resulting from the ozone treatment. Filtracarb® FY5 was selected due to its high surface area and retentive pore structure, smaller molecules.

Following adsorption, the water is disinfected for supply to the distribution network.

CPL Carbon Link provides a range of Granular Activated carbon (GAC) products from municipal water treatment. The key features of these products are:

• Granular coal and coconut shell activated carbons enable optimum product selection
• Range of activity levels and pore size distributions provide a flexible approach to adsorption
• High density (GAC) products give maximum volume activity
• Excellent thermal reactivation characteristics
• UK Drinking Water Inspectorate (DWI) approved

Typical Product Properties