Determining Isoproturon & MCPA capacity in GAC filters using the RapStech® service


Northumbrian Water


Feb. to April ‘08

RapStech® provides a rapid method using Rapid Small Scale Column Tests (RSSCTs) to test the capacity of Granular Activated Carbon (GAC) and determine the optimum time for regeneration or replacement. In this project, field spent GAC was tested using RSSCTs and site water in the laboratory with pesticides such as Isoproturon and MCPA. The quality of the GAC was also assessed for physical and chemical characteristics.

The data obtained suggest that following time in service the field spent GAC has resulted in physical and chemical changes in adsorption characteristics. The data obtained can be used to assist with GAC service life evaluation. This strategy can provide the water utility with a greater understanding of this critical asset and thus the capability to make more informed operational decisions regarding regeneration frequency.