BiAqua

BIOFOULING

Biofouling or biological fouling is the undesirable accumulation and growth of microorganisms on wetted structures, like membranes, cooling towers or water distribution networks.

Membrane biofouling is a worldwide problem and is established in all reverse osmosis or membrane filtration units if sufficient phosphate is present. Nanofiltration and reverse osmosis applied for surface water and wastewater treatment will result in severe membrane fouling when no pretreatment is installed. Despite extensive pretreatment, biofouling may result in a reduced production capacity and/or a frequent membrane cleaning. In all cases the consequence is an increase in costs per amount of produced or treated water.

The desalination market where nanofiltration and reverse osmosis are the biggest application, has witnessed a significant upturn in recent years. The worldwide capacity is approximate as of 42 million m3/ day in 2008. The Middle East is responsible for 50% of this desalination capacity whereas 15% each in Asia, US and Europe. This market still grows driven by the increasing world population and the diminishing freshwater sources which is a result of global warming.

The negative impact of biofouling estimated in billions of euros each year, as it leads to increase in down time of installation, increase in operating & maintenance cost and decrease in life of membranes.

Cooling tower biofouling potentially leads to excessive growth of Legionella and other harmful bacteria. Furthermore, biofouling may lead to underdeposit corrosion, considerably lowering the lifetime of the assets. Currently, biocides are used to prevent biofouling, resulting in discharge of biocides to the environment.

Biofouling of water distribution networks leads to accumulation of potential harmfull bacteria, water discoloration and taste and odour issues. Water supply companies need to extensively treat the water to prevent biological growth, or have to resort to chlorination of the water leaving the pumping station and sometimes chlorination in the distribution network as well. Chlorine in drinking water does not only leave a bad taste and odour, but also leads to the formation of carcinogenic haloforms.

The BiAqua solution is able to eliminate phosphate from water, to such an extent that biofouling (bacterial growth) is prevented.