The filtrate is typically characterized by a complete removal of suspended solids, a log 5 reduction (>99.999%) of bacteria such as Cryptosporidium, a filtrate turbidity <0.1 NTU (no matter what the feedwater turbidity is) and an SDI (Silt Density Index) < 2.
This means that the filtrate is ready for reuse in drinking water applications or is perfectly pre-conditioned to serve as feedwater for a reverse osmosis installation.
Discontinious dead-end filtration processes
AQUALITY® membrane filtration processes are generally discontinuous dead-end filtration processes. Contrary to the EXSEL® processes that use cross-flow filtration to keep the membranes clean. AQUALITY® membrane filtration processes are characterized by a dead-end filtration cycle which is being alternated with a periodic backwash cycle.
The membranes used for this application are hollow fibre membranes and a differentiation can be made in the filtration mode which can be 'inside-out' or 'outside-in'. Waterleau developed a special range of proprietary membrane cleaning agents.
- Municipal drinking water production
- Industrial process water make-up
- Feedwater sources for drinking water or process water can be of any kind, such as
- Turbid ground water
- Surface water