Water Filtration Technical Services – Media Filters Monitoring & Maintenance

Water Filtration Technical Services of Pacific Water Technology include a routine maintenance program where media filters including iron removal filters & activated carbon filters are monitored, their performance evaluated and parameters fine-tuned to optimise the performance of media filtration.

Example – 63″ Carbon filter Monitoring & Commissioning

Monitoring of the 63″ Carbon Filter – Iodine Test

An example is the maintenance of commercial activated carbon bed filters used for chlorine removal for a large bottling plant. To monitor the status of the granular activated carbon, an iodine test is carried out that determines an iodine number for the carbon. The iodine number is defined as the milligrams of iodine adsorbed by 1.0g of carbon when the iodine concentration of the filtrate is 0.02 N (0.02 mol.L-1 ). The carbon samples are taken from different locations in the vessel to obtain a representative sample. The exhaustion of activated carbon filters can be estimated, hence optimising the frequency of iodine number testing. For example, a 63″ carbon filter’s expected carbon capacity for dechlorination will be:

1 x 63″ Carbon filter @ 1ppm chlorine at 350 LPM    –     220ML Raw Water
2 x 63″ Carbon Filter @ 3ppm chlorine at 350LPM each   –   240ML Raw Water
For 780kg carbon per vessel.

Removal of exhausted carbon media – Vacuum Truck

Once the iodine number had reached the required threshold where dechlorination is no longer effective for the current media bed contact times, it’s time to replace the carbon media. The spent media is extracted from the top of the filter vessel using a vacuum truck, a suction hose/lance. The top flange and laterals on the filters vessels would need to be removed to access the carbon and remove it.

Exhausted Carbon removal via vacuum truck & suction hose/lance


Top laterals of the 63″ carbon filter vessel that have been removed to suck out the exhausted carbon media


Bottom lateral of the 63″ carbon filter vessel after emptying the exhausted carbon, water is filled to cover the laterals so that they are not damaged during refilling


                                                                                                                                                                                                                                                                                                                  Refilling activated carbon media via a media funnel

Recommissioning of the 63″ Carbon Filter Vessels after refilling

For the activated carbon replacement, granular activated carbon that has been acid washed is used. The acid wash removes most of the ash content in the carbon that if left unwashed will hamper the performance efficiency. The high grade activated carbon used means that there will be minimal pH fluctuations once the filter has been recommissioned. A number of backwash and rinse cycles will have to be performed after carbon replacement to ensure the carbon bed is compact and settled, all fines in the carbon media have been removed and the activated carbon is pH neutral.

Backwashing/rapid rinsing the carbon filter vessels to ensure optimised performance


Pacific Water Technology also services & maintains other filtration equipment, including Reverse Osmosis (RO) Systems.

For any enquiries, please do not hesitate to get in touch with us:

More about commercial activated carbon filters.
Email: sales@pacificwater.com.au
Phone: 07 3376 9009