Municipal water treatment facilities will spend $4.5 billion this year for filters and clarifiers, according to the latest forecast by McIlvaine Company based on combined projections in four McIlvaine Market reports.

China is presently the largest purchaser of filtration and sedimentation equipment for new water treatment facilities. There is an international participation in the Chinese market. Veolia is operating Chinese water treatment facilities servicing over 27 million people and Suez has 23 joint ventures in water & wastewater serving 17 municipalities.

Cross-flow membrane technologies are gaining market share at the expense of granular media filters, the reports show. There is increasing concern about contaminated drinking water and microfiltration can be more efficient than a gravity media filter in removing harmful microbes. In some cases plants are going even further and installing the more efficient ultrafiltration membranes, McIlvaine says. When brackish water must be treated reverse osmosis is being used as a solution.

Cartridges are used in drinking water systems where operation is only a few months per year, such as summer resorts in northern climates, because the cartridges are not self-cleaning. An alternative to cartridges is automatic back wash filters, which are making inroads into municipal drinking water treatment. These filters were originally developed for drip irrigation, but are proving to have benefits in drinking water treatment, McIlvaine says.

Dissolved air flotation provides small particle removal and takes up less space than clarifiers. Hydrocyclones are very infrequently used and only for pre- treatment when there are relatively large solids, the reports show.