Agriculture Reference
In-Depth Information
in a safe way for, for instance, irrigation of crops or non-potable domes-
tic purposes such as laundry or cleaning. The annual production of grey
wastewater for a household is 112 L per household per day, which will
result in an annual amount of 31 m
3
of treated wastewater, assuming a 75%
recovery and treatment effi ciency.
TABLE 9:
Summary of examples of on-site technologies and potential resources recovered.
Technology
Size
Potential resource recovery
per household per year
Benefit
On-site rainwa-
ter harvesting
with posttreat-
ment
Roof: 36 m
2
Storage tank:
1.5-2.0 m
3
Water: 20.3 m
3
(70% efficiency)
49% reduction in water
demand
EcoSan and
biofiltro
EcoSan: 1.5 m
2
Biofiltro: 2 m
2
N: 5.7 kg
P: 1.5 kg
K: 2.4 kg
Flush water: 51 m
3
Treated grey water: 31 m
3
(75% efficiency)
300-750 m
2
of maize,
producing an estimated
4.5 tons/ha
Redundant flush water:
51 m Recovered grey
water accounts for 60%
of the water demand
(Vermi-)com-
posting
Composting struc-
ture: 1m
3
N: 6 kg
P: 1 kg
OM: 200 kg
Worms: 10 kg from 1 kg/year
300-750 m
2
of maize,
producing an estimated
4.5 ton/ha
The annual amount of organic waste produced per household in Xochi-
milco is approximately 1000 Kg. Assuming a 20% mass reduction this re-
sults in an annual production of 800 kg of compost from the organic waste
of one household. The composition of compost generated will differ per
location as it depends upon the organic waste that is composted, the qual-
ity of the composting facility (aeration, temperature regulation) as how
the compost is maintained (moisture content and temperature). Taking the
general values shown in Table 2 the amount of nutrients recovered annu-
ally by one household is 6 kg N and 1 kg P. Compost is also a source for
organic matter (OM), which can be used as soil conditioner. The annual
production of OM is calculated to be 200 kg OM. Based on N-require-
ments, this is enough to cultivate 750 m
2
of hybrid maize capable produc-
ing 4.5 ton/ha (application load of 80 ton/ha). However, if P-availability
