Design for a water treatment plant:
- Produce as individuals a single tab Excel spreadsheet which shows a rough initial design for a water treatment plant taking 15MLD of water with 100 mg/l SS from a lake at 750mAOD, passing it through settlement tanks on to pressure sand filters, and from there into a chlorine contact tank to TR60 of 30 mins HRT and 1m water depth at 575mAOD. Distance from Lake to CCT is 1500m. Fall on ground is constant along this 1500m.
- Numbers and diameters for circular settlement tanks and sand filters, external and internal dimensions of CCT, theoretical and actual pipe diameters sizes will be needed to be calculated as a minimum.
Rules of thumb for design:
Surface loading settlement tanks 1m/h
HRT settlement tanks 2h
Max diameter settlement tanks 30m
Surface loading sand filters 15m/h
Sand filter depth 2m
Max diameter sand filters 3m
Static head required for sand filter operation 10m
Superficial velocity pipework 1.5m/s