AquaEst Rain PC

Rainwater harvesting using the RainPC

AquaEst offers a wide range of water purification products which are applicable in various situations. In the Rain PC system, rainwater is purified by means of multi-stage and multi-media filtration. It’s a three-stage filtration system using 80 micron and 10 micron pre-filters along with an activated carbon filter in which the colloidal silver-ceramic balls and metallic copper are embedded. The RainPC eliminates (pathogenic) bacteria and organic and inorganic pollutants/contaminants.

It is suitable for individual homes and small communities. However for application in third world countries, support from local government or NGO is required

History and social context

The RainPC was successfully installed in 8 rural schools providing over 2000 children with clean and safe drinking water in Thailand. These projects are realized since 2008 by a Dutch NGO, “HOAT”.

Contents

Suitable conditions

Advantages Disadvantages/limitations
- A whole treatment system approach is offered
- Does not introduce toxic chemicals
- Requires no power (for gravity unit)
- Low maintenance
- Comply with WHO Guidelines and US EPA requirements (<1 cfu E.coli/100-ml sample)
- Robust product
- Not 100% effective against viruses
- An effectively functioning RainPC requires a good complete system (adequate roof, gutters, buffer tanks, first flush, pre-filtration)



The RainPC is suitable anywhere where rainwater harvesting is possible.

Highly effective for: Somewhat effective for: Not effective for:
- Pathogenic bacteria (E. coli, coliforms, entercoccus)

- Algae

- Viruses

- Organic substances

- Protozoa

- Helminths
- TDS

Treatment process:
Particle removal, disinfection and safe storage
Inlet water criteria:
rooftop harvested rainwater

Construction, operations and maintenance

Operation of the Rain PC is very easy. It can be operated at low gravity pressure, as well as pump pressure up to 6 bar ( in case of underground storage ). The water flow is maximum 8 litres/minute, though this can change depending on the level of pollution. The RainPC school application in Thailand where a constant volume is set at max. 8 litre/hour.

Practically no maintenance is required. For the RainPC system, the 80 micron filter has to be inspected and cleaned regularly. The 10 micron prefilter and filter cartridge with activated carbon, silver ceramic balls and metallic copper have, in adequate systems, a capacity of up to 150.000 litres without further maintenance.

There is no possibility for local production of the purifying/conserving equipment. However other rain harvesting tools, such as gutters, taps or tanks can be produced locally.

Estimated Lifespan

The entire system has a service life of at least 15 years. The cartridges and 10 micron pre-filter can process a maximum of 150 000 litres, though the lifespan depends on the extent of pollution.

Suppliers

AquaEst Europe

Costs

Capital cost refers to an integrated and complete new / revised rainwater harvesting systems (new gutters, new piping, reparation main storage tanks, first flush, revision of buffer tanks and tap units). Cartridge set needs to be replaced every 150 m3. The RainPC is estimated to fulfil its 15 years lifespan with annual capacity of 100 m3.

Capital cost Operating cost Replacement cost Estimated 5 year cost Cost / metre cubed treated
€ 1.000 €0 € 200 * 10 = € 2.000 € 2,00


Acknowledgements

This article is based on a factsheet from Aqua For All…..