360
w. Neubrand et al.
1 Introduction
Conservation of water is not an issue only in arid climates with limited water
resources but also in European countries with sufficient and even sometimes
excessive natural resources.
Water management is becoming increasingly important due to urbanization.
Whereas in 1951 only 30% of world's population were living in cities, this number
is expected to increase to more than 60% in 2025 (Jackson and Orb 2000).
Until now in modern construction, water is just considered a utility like electric
current and not as part of our natural environment. Few attempts are being made
towards reduction of overall water consumption and towards a more sophisticated
use of this resource.
Actual human water consumption per capita varies from 100 - 300 liters person-I
day-I in most of the countries of the world without significant change in the last 20
years. In most buildings a single water quality is used for all purposes in the
household, ranging from drinking to toilet flush.
2 Domestic Water Consumption, Wastewater Characteristics and Treatment Systems
General figures for the various purposes of domestic water consumption are
shown in Fig. 1. Only a very small amount is used for drinking and other direct
human consumption. Body care and laundry represent a large fraction of water
consumption and a significant portion is used for purposes like toilet flush.
Usually, high-quality drinking water is used for all purposes.
On the other hand, domestic wastewater has a broad range of variation.
Blackwater (feces, urine, and flushing water) contains most of the organic
contamination (C,N,P) and is also highly microbiologically contaminated.
However most of domestic wastewater is greywater, with low organic and only
low to medium microbiological contamination.
w. Neubrand et al.
1 Introduction
Conservation of water is not an issue only in arid climates with limited water
resources but also in European countries with sufficient and even sometimes
excessive natural resources.
Water management is becoming increasingly important due to urbanization.
Whereas in 1951 only 30% of world's population were living in cities, this number
is expected to increase to more than 60% in 2025 (Jackson and Orb 2000).
Until now in modern construction, water is just considered a utility like electric
current and not as part of our natural environment. Few attempts are being made
towards reduction of overall water consumption and towards a more sophisticated
use of this resource.
Actual human water consumption per capita varies from 100 - 300 liters person-I
day-I in most of the countries of the world without significant change in the last 20
years. In most buildings a single water quality is used for all purposes in the
household, ranging from drinking to toilet flush.
2 Domestic Water Consumption, Wastewater Characteristics and Treatment Systems
General figures for the various purposes of domestic water consumption are
shown in Fig. 1. Only a very small amount is used for drinking and other direct
human consumption. Body care and laundry represent a large fraction of water
consumption and a significant portion is used for purposes like toilet flush.
Usually, high-quality drinking water is used for all purposes.
On the other hand, domestic wastewater has a broad range of variation.
Blackwater (feces, urine, and flushing water) contains most of the organic
contamination (C,N,P) and is also highly microbiologically contaminated.
However most of domestic wastewater is greywater, with low organic and only
low to medium microbiological contamination.