Greywater Recycling: Field Experience
365
6 Field Installations in Austria
The greywater recycling process has been implemented in two residential
complexes in Vienna (Treberspurg and Hofbauer, 1998). A key issue for the
design of these projects was the construction of low-energy-housing with
minimum impact on the environment. Thus, the integration of a water-recycling
system was the next step after energy-efficient construction.
6.1 Key Data of Water and Thermal Recycling System
The key data of the two installations are listed in Table 1. Both were installed in
housing complexes with approx. 500 flats each. The amount of recycled water is
30 m 3 /day each corresponding to 30 I person- 1 dail.
Table 1. Key data of greywater and thermal recycling systems
Site 1
Site 2
No. of flats
514
500
Greywater amount in m' day-l
60
60
Recycled water in m' day-l
30
30
Proj. Heating Power in kW
81
81
COP-Value of Heat Pump
8.4
8.4
Further, a heating power of approx. 80 kW can be recovered with the integrated
thermal recovery system.
The major components of the treatment system (media filter, nanofiltration
unit, and UV system) are shown in Fig. 4 and 5.
6.2 Greywater and Recycled Water Quality
The quality of greywater and recycled water is given in Table 2. Whereas the
organic contamination is rather stable in the range of 200 - 300 mg rl COD, the
microbiological contamination shows a broader range of variation, e.g., coliforms
ranging from 300 to 2000000 CFU per 100ml.
Water samples from different locations inside the treatment system are shown
in Fig. 6. The original greywater (sample no. I) is turbid and has a characteristic
smell. After filtration, the sample is clear and can be treated in the membrane unit.
The final product is shown on the right side (sample no. IV).
365
6 Field Installations in Austria
The greywater recycling process has been implemented in two residential
complexes in Vienna (Treberspurg and Hofbauer, 1998). A key issue for the
design of these projects was the construction of low-energy-housing with
minimum impact on the environment. Thus, the integration of a water-recycling
system was the next step after energy-efficient construction.
6.1 Key Data of Water and Thermal Recycling System
The key data of the two installations are listed in Table 1. Both were installed in
housing complexes with approx. 500 flats each. The amount of recycled water is
30 m 3 /day each corresponding to 30 I person- 1 dail.
Table 1. Key data of greywater and thermal recycling systems
Site 1
Site 2
No. of flats
514
500
Greywater amount in m' day-l
60
60
Recycled water in m' day-l
30
30
Proj. Heating Power in kW
81
81
COP-Value of Heat Pump
8.4
8.4
Further, a heating power of approx. 80 kW can be recovered with the integrated
thermal recovery system.
The major components of the treatment system (media filter, nanofiltration
unit, and UV system) are shown in Fig. 4 and 5.
6.2 Greywater and Recycled Water Quality
The quality of greywater and recycled water is given in Table 2. Whereas the
organic contamination is rather stable in the range of 200 - 300 mg rl COD, the
microbiological contamination shows a broader range of variation, e.g., coliforms
ranging from 300 to 2000000 CFU per 100ml.
Water samples from different locations inside the treatment system are shown
in Fig. 6. The original greywater (sample no. I) is turbid and has a characteristic
smell. After filtration, the sample is clear and can be treated in the membrane unit.
The final product is shown on the right side (sample no. IV).