Water treatment processes are not without problems that can turn into a true nightmare. One of them is when the activated carbon does not fulfill its function of removing free chlorine and organic matter from the water.
The solution to this common problem is quite simple: sufficient contact time and backwash flow are required.
It is the time that the flowing water remains in contact with the coal. If this time is less than required, the carbon does not manage to destroy the free chlorine (which occurs by chemical reaction with the carbon) and to retain the organic matter. The minimum contact time required depends on the average particle size of the carbon and the contaminant content of the water.
The water flows downward through the carbon bed, so the carbon particles are compacting and sticking together. This makes it necessary to backwash to detach them. If the backwashing is not done frequently and with enough flow for the bed to expand, the carbon bed ends up cracking and the water begins to flow, not through the carbon particles, but through the cracks. As a consequence, the water is no longer purified. In these cases, the user often believes that the carbon was saturated, which is not the case.
How can we know which backwash flow and contact time are adequate?
Through simple questions about the water and the conditions of your process, Carbotecnia engineers can calculate the contact time and flow required for the coal to operate properly.