Agriculture Reference
In-Depth Information
is collected with a 70% effi ciency on the before mentioned roof surface
(36 m 2 ), this can result in a capturing of 20.3 m 3 , which accounts for 49%
of the annual water demand of a peri-urban household not connected to the
centralized water supply system (41.6 m 3 /year) [32].
TABLE 8: Overview of technical systems for concept scenario 3—Concept of natural
resources flows.
Concept scenario 3—Centralisation
Water supply
Wastewater
Agriculture
Solid waste
- Connection
to centralized
water supply
- Connection to cen-
tralized sewer system
and treatment
- Use of compost in lo-
cal gardens/agriculture
- Separation of organic
waste - Centralized com-
posting of organic waste
Examples of resources fl ows from earlier discussed technologies are
as follows: Through the implementation of an on-site RWH system with
post-treatment the inhabitants will be less depended on the centralized wa-
ter supply system for their water supply. If all annual precipitation (807
mm) is collected with a 70% effi ciency on the before mentioned roof sur-
face (36 m 2 ), this can result in a capturing of 20.3 m 3 , which accounts for
49% of the annual water demand of a peri-urban household not connected
to the centralized water supply system (41.6 m 3 /year) [32].
The implementation of an EcoSan and biofi ltros for the treatment of
feces, urine and grey water at household level will enable the recovery of
N, P and Potassium (K) as well as water. Based on data for one household
the recovered amounts can be 5.7 kg N/year, 1.5 kg P/year and 2.4 kg
K/year. Based on N-requirements, this is enough to cultivate 750 m 2 of
hybrid maize capable producing 4.5 t/ha (application load of 80 tons/ha).
However, if P-availability is limiting, the cultivatable area is 500 m 2 . For
K this is 300 m 2 [37,38]. This can deviate, depending on local conditions.
If households that currently make use of fl ush toilets (using an average
of 7 L per fl ush) also construct EcoSan toilets, water can be saved. With
an average of 4 inhabitants per household and 5 fl ushes per person per
day (one fl ush per visit), an annual 51 m 3 can be saved per household. The
use of a biofi ltro will ensure that little polluted wastewater can be reused
 
Search WWH ::




Custom Search