The drawbacks of using intermittent doses of sodium hypochlorite as an oxidising biocide in the pre-treatment line of a reverse osmosis desalination plant

Abstract

This article reports on the adverse effects on the microbiological quality of sea water with a high degree of biological contamination captured by an open intake system when it is subjected to intermittent, or shock treatment, doses of an oxidising biocide, such as sodium hypochlorite NaClO (KmnO4 O3, H2 O2), even though the purpose is to control microbiological development in the process water that contaminates the conduits, the units in which the processes are carried out and/or the unit operations, especially inside the membrane modules used in potabilising plants to desalt sea water and/or brackish water by the reverse osmosis technique. The uncontrolled development of a great diversity of microorganisms on the active layer of the membranes causes serious problems in the operation of this type of potabilising plant.