An innovative greywater treatment system for urban areas ... - SuSanA

ut in a hotel the drain from showers and bathtubs plays the leading part. In total a much
bigger volume accumulates per capita per day in buildings where persons stay overnight.
The serial MBR plant is constructed exactly for the volume of process water demand in
the building, only the greywater which is necessary for reuse is treated. The water balance of
greywater production and reuses of recycled water shows a better harmony.
The economic issues of treatment plants and house installations differ significantly. In the
4-star hotel in Berlin the investment cost of the plant is higher, this is caused by bigger
containers to store the greywater. The treatment plant in Eschborn purifies small volumes of
greywater, hence the tanks are smaller. It can also be seen in the size of required space for
the system. For the piping system it is the same case, the SANIRESCH project is only
equipped in one-third of the GIZ’ s headquarters building, whereas the 4-star hotel’s system
is fully equipped to service the entire edifice.
The maintenance and inspection of the respective plants is planned in both cases to take
place once a year. In the hotel the estimated time expense is 3 h/a, for the plant in Eschborn
there is no data available, due to the operation time < 1 a. For the research project an
additional cleaning procedure of the intermediate storage tank is scheduled to take place
twice a year.
As part of the research project there are weekly sampling procedures, these are
necessary to get insights into the functioning of the system. Operational modifications and
experiments are scheduled to analyse the treatment plant. For serial products in
standardised plants it is not required, their production is stable and thus it is not planned to
test different modifications of operation.
According to current performance of the treatment plant in Eschborn a removal of excess
sludge is necessary every 4 weeks, this is carried out manually. In a standard plant
automatic removal of excess sludge can be implemented, depending on the necessity.
These parameters need to be observed in the initial phase of operation, to work out a
strategy for stable serial performance of the standard plant.
Sampling taps, aeration of the intermediate storage tank, remote data control and remote
control of the treatment plant are special features of the SANIRESCH plant and are due to it
being a research project.
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