The greywater is water that comes from the showers, laundry and kitchen. Basically the water that contains inorganic particles like soap, oil and some synthetic compounds.
This water is used once for differents purposes and then thrown to sewage systems or waterbodies like rivers, lagoons and seas. These actions are very harmful for the nearby grey water effluent ecosystems and the environment. Taking in account the facts that have been happening through the years (soil and water pollution, loss of biodiversity and climate change) it is necessary to take action about this situation that affects the whole planet.
In Richmond Vale Academy we are building a greywater recycling system in which we are taking the water from the laundry and six showers, we estimate to recycle about 1000 liters of water per day.
For design and building this system, is necessary to consider the type of contaminants, the amount of water, available materials and the use to which it wants to give the treated water. The latter consideration is very important due to that this kind of water can’t be used for human consumption, which includes drinking, showers, washing kitchen utensils and cooking.
Some benefit we are going to get with this system is irrigation of a passion fruit field and water storage for the organic garden, however if in a near future this system can be improved to increase the quality of the water recycled, it could be used for fish production.
The grey water system consists of three stages.
First: A pipe line brings the water from the showers and laundry to a first tank which has the function of reducing the speed of the water to make a sedimentation process in the two next tanks.
Once the water comes to the first tank, it starts to be calm, so a second pipe receives this water to pass to the next tank in which the quiet water begins a sedimentation process where the particles with more weight are going to the bottom of the tank and the insoluble particles stay in the surface of the water; this process is repeated one more time in the third tank.
Second: Then to the third tank, the water comes without sedimentable solids, that means that the first process has reduced the turbidity of the water. The function of the second stage includes having a deeper cleaning of the water by a gravel filter and the action of the roots of hydroponic plants.
Third: Finally the water that comes from the gravel filter passes to a small charcoal filter, which removes the particles that couldn't be removed by the previous process for then being taken to the storage pond.
RVA has a duty to the community, where this project is made to teach people to find alternatives for fighting the effects of climate change (like lack of water) and avoid contamination of water.
Written by Kelly Quintero