Clarification of a highly turbid karstic water by microfiltration

Memcor® Continuous Microfiltration (CMF) is a technology that is very efficient for the clarification and disinfection of karstic waters for the production of drinking water. In Héricourt-en-Caux (Normandy), a Memcor® CMF plant is treating a particularly difficult water with a background level of turbidity between 3 and 30 NTU and recurrent events of several hundred NTU lasting between some hours and several days. The turbidity of the permeate is consistently between 0.1 and 0.2 NTU. A fouling problem has been solved by injection of a coagulant and optimisation of the cleaning conditions.

Memcor ® CMF is a very efficient microfiltration process that allows the removal of even very high concentrations of suspended matter from water, in general without continuous use of chemicals. However at the Héricourt-en-Caux site, the water is particularly difficult to treat, with very high levels of turbidity, TOC and bacteria and the process operated under standard conditions reached its limits. Injection of a coagulant upstream the membranes, optimisation of the chemical cleanings and partial use of a borehole water allowed to obtain very satisfactory operation conditions with an average cleaning frequency of once every two weeks.