Immersed membrane filtration for the production of drinking water: Case studies

This paper presents the application of a new immersed microfiltration membrane through two case studies: Rothesay (New Brunswick) and Collingwood (Ontario), Canada. Both of these municipal plants are equipped with membrane clarification processes based on ZeeWeed(R), a shell-less, outside-in hollow fibre membrane immersed into a process tank. Direct filtration results were illustrated using the Collingwood plant. The first year of operation, with water temperature as low a 1 degrees C, has demonstrated the low fouling tendency associated with low transmembrane pressures. The permeate quality was excellent with on-line particle counts (>2 mu m) below 2 per ml. The Rothesay plant was used as an example of combining oxidation for iron and manganese removal with immersed membrane filtration. Without sophisticated process control, a treated manganese level of 0.02 mg/l was achieved with highly variable feed values of up to 1.5 mg/l.