In recent years, there has been a significant increase in the use of biocides for cooling water applications due to the use of phosphate as a corrosion and scale inhibitor, and the problem is further compounded by the use of recycled wastewater containing organic and phosphates.

Oxidizing biocides such as chlorine, bromine, ozone, chlorine dioxide, etc, do not entirely provide a solution to control microbial population and as low as possible.

In fact, a non-oxidizing biocide such as Quats/Benzalkonium chloride, Isothiazolines, Carbamate, glutaraldehyde, etc. are applied on a periodic and shock dose basis effectively penetrates and dislodges slime/algae due to surfactant properties and at time same killing aerobic and anaerobic bacteria, fungi, etc. Oxidizing biocides plays dual role of initially destroying organic or process contaminants and subsequently acting as low level background biocide however it has limitation of not penetrating & dislodging slimes and algae.

Consequently many water treatment companies design and operate microbiological control programs that combine oxidizing, non oxidizing biocides and biodispersants   which synergistically and effectively   control host of microbial population.

Productive biocide programs are often based on some degree of trial and error by site engineers, associated with past experience and assisted by their technical department