CHAPTER ONE
1.1 Introduction
Globally, water has been a major requirement for the growth and development of
biotic life. Water has for long exerted strong influence on the choice of place for human
settlement. Of all human activities, agriculture and industrial activities have been identified as
the highest consumer of water (Nweze and Chimboh, 2003). With time, increase in
population and sophisticated advancements in man’s industrial sectors have resulted in
drastic scarcity of available natural/clean water. Hence, the use of waste water either in the
raw state or purified form in agricultural activities, especially in the off season vegetable crop
production and ornamentals became imperative for decades in Europe, North America and
Australia (Dolgenet al., 2004). Following the success of propagating vegetable crops,
ornamentals and lawn maintenance, using waste water, the practice became recognized in
many other countries like India, China, Middle East etc. (Hampet al., 1976).
In the developing countries like Nigeria, Ghana, Cameroun, Togo, waste water is used
in vegetable production, especially in the dry season/off season. Waste water used
includedomestic waste water and sewage effluent (Nweze and Chimboh, 2003). In Egypt,
acute shortage of natural/clean water has resulted in the development of alternative sources of
obtaining water for agricultural production. Bashiret al., (2006) reported that in Egypt, due to
increase in population and agricultural activities, the use of waste water and sewage effluent
has progressively increased particularly in the urban cities. The authors reported that waste
water is deposited on the ground to enable its reclamation for further reuse. They also
reported the reclamation of about four million m3 and two million m3 water in Cairo and
Alexandria respectively and the salvaged water could be used to irrigate about 300,000
fadama for vegetable production
Many authors have appraised the use of sewage water in vegetable production but did
not emphasize the health hazards posed by consuming such vegetables (Dolgenet al., 2004,
Bashir et al., 2006, Singh and Agrawal, 2010, Maryam, 2011). Dolgenet al., 2004 reported
the benefits of irrigating agricultural crops with sewage water to include; provision of
chemical nutrients like nitrogen, phosphorus, boron, manganese, copper and zinc to the crops.
Maryam (2011) pointed out that the effects of these chemical mineral nutrients in rapid
growth of vegetables have stimulated interest in the use of sewage effluent in vegetable
production. The author further reported that irrigating vegetables with waste water of
whatever origin could pose health hazards due to the absorption and accumulation of heavy
metals in the produced crop, particularly vegetables.
In the developed countries, with large-scale sewage treatment plant, water salvaged
from sewage is properly treated before recycling for various uses (Batstone and Keller,
2003). In the developing countries, Imhoff treatment equipment in use for sewage water
extraction have facilities that were below international standard because the tanks are
exposed to the air, while the drying beds and the oxygenated ponds may not be functioning
effectively (Llyod, 2000). The type of vegetables produced during off-season using sewage
effluent (Water) for water supply varies from one locality to another because of the level of
revenue generated. In the South Eastern Nigeria, popular vegetables produced during offseason
include:Telfairiaoccidentalis, AmaranthusviridisandCorchorusolitorius, while in the
South Southern Nigeria, the most popular off-season vegetable is Taliniumtriangulare. In the
Northern states, off-season vegetables include Lactucasativum, Daucuscarota andBrassica
oleracea. These vegetables often appeal to the eyes due to their freshness. They (vegetables)
are variously used in preparing delicious foods eaten in restaurants, various eating spots like
motor parks, market, roadsides (Sold by food vendors), Universitycommunities and in big
national and international hotels. Generally, people are ignorant of the source of water with
which these vegetables were irrigated. Reports that sewage effluent- irrigated vegetables
absorb and accumulate heavy metals, becomesnecessary that the extent of the heavy metal
accumulation in the edible parts of the vegetables should be made known, with the view of
ascertaining the safety of human health.
Of all the vegetables produced off-season using sewage..
1.1 Introduction
Globally, water has been a major requirement for the growth and development of
biotic life. Water has for long exerted strong influence on the choice of place for human
settlement. Of all human activities, agriculture and industrial activities have been identified as
the highest consumer of water (Nweze and Chimboh, 2003). With time, increase in
population and sophisticated advancements in man’s industrial sectors have resulted in
drastic scarcity of available natural/clean water. Hence, the use of waste water either in the
raw state or purified form in agricultural activities, especially in the off season vegetable crop
production and ornamentals became imperative for decades in Europe, North America and
Australia (Dolgenet al., 2004). Following the success of propagating vegetable crops,
ornamentals and lawn maintenance, using waste water, the practice became recognized in
many other countries like India, China, Middle East etc. (Hampet al., 1976).
In the developing countries like Nigeria, Ghana, Cameroun, Togo, waste water is used
in vegetable production, especially in the dry season/off season. Waste water used
includedomestic waste water and sewage effluent (Nweze and Chimboh, 2003). In Egypt,
acute shortage of natural/clean water has resulted in the development of alternative sources of
obtaining water for agricultural production. Bashiret al., (2006) reported that in Egypt, due to
increase in population and agricultural activities, the use of waste water and sewage effluent
has progressively increased particularly in the urban cities. The authors reported that waste
water is deposited on the ground to enable its reclamation for further reuse. They also
reported the reclamation of about four million m3 and two million m3 water in Cairo and
Alexandria respectively and the salvaged water could be used to irrigate about 300,000
fadama for vegetable production
Many authors have appraised the use of sewage water in vegetable production but did
not emphasize the health hazards posed by consuming such vegetables (Dolgenet al., 2004,
Bashir et al., 2006, Singh and Agrawal, 2010, Maryam, 2011). Dolgenet al., 2004 reported
the benefits of irrigating agricultural crops with sewage water to include; provision of
chemical nutrients like nitrogen, phosphorus, boron, manganese, copper and zinc to the crops.
Maryam (2011) pointed out that the effects of these chemical mineral nutrients in rapid
growth of vegetables have stimulated interest in the use of sewage effluent in vegetable
production. The author further reported that irrigating vegetables with waste water of
whatever origin could pose health hazards due to the absorption and accumulation of heavy
metals in the produced crop, particularly vegetables.
In the developed countries, with large-scale sewage treatment plant, water salvaged
from sewage is properly treated before recycling for various uses (Batstone and Keller,
2003). In the developing countries, Imhoff treatment equipment in use for sewage water
extraction have facilities that were below international standard because the tanks are
exposed to the air, while the drying beds and the oxygenated ponds may not be functioning
effectively (Llyod, 2000). The type of vegetables produced during off-season using sewage
effluent (Water) for water supply varies from one locality to another because of the level of
revenue generated. In the South Eastern Nigeria, popular vegetables produced during offseason
include:Telfairiaoccidentalis, AmaranthusviridisandCorchorusolitorius, while in the
South Southern Nigeria, the most popular off-season vegetable is Taliniumtriangulare. In the
Northern states, off-season vegetables include Lactucasativum, Daucuscarota andBrassica
oleracea. These vegetables often appeal to the eyes due to their freshness. They (vegetables)
are variously used in preparing delicious foods eaten in restaurants, various eating spots like
motor parks, market, roadsides (Sold by food vendors), Universitycommunities and in big
national and international hotels. Generally, people are ignorant of the source of water with
which these vegetables were irrigated. Reports that sewage effluent- irrigated vegetables
absorb and accumulate heavy metals, becomesnecessary that the extent of the heavy metal
accumulation in the edible parts of the vegetables should be made known, with the view of
ascertaining the safety of human health.
Of all the vegetables produced off-season using sewage..
