234
A. Z. Yaser and N. N. Safie
by Bhakar et al. (2016), the impact of treated water on global warming potential is
negligible while the impact of fresh tap water has 77% impact and treated water used
for irrigation is the origin of 0.01% of the impacts only. The study also shows that
the use of treated water for gardening activities will reduce the environmental impact
of the university by almost 25%.
Wastewater recycling for irrigation is a potentially important as well as relatively
low-cost source of water and therefore is used in more than 40 countries (Jiménez
and Asano 2008). Instead of being used for irrigation, Ghangrekar et al. (2007) have
utilized a sewage pond for aquaculture, by releasing fish like tilapia into the pond.
Also, duckweed has been reproduced in the same sewage pond and has shown that
sewage pond is feasible for aquaculture activities.
Sewage generated from colleges and universities contain low heavy metal and
contaminants which make it suitable to be reused on-site for nonpotable uses such
as lawn irrigation and toilet flushing. Toilet flushing can be done in a compound
such as hotel as being done by March et al. (2004). The water is filtrated, treated,
and disinfected using hypochlorite as the disinfecting agent before it is being used in
toilet flushing system. An average amount of water of 5.2 m
3 /d
−1 was reused, which
represents 23% of the total water consumption of the hotel.
Instead of toilet flush system, analysis by Zhang et al. (2017) has shown that
bathing sewage is very suitable for the waste heat recovery by using sewage source
heat pump because of its suitable water flow, water temperature, and water quality.
Also, it is economically feasible with payback period 3.39 year. This is suitable to
be used to preheat the water bath in hostel shower rooms.
Based on the life cycle assessment (LCA) by Raghuvanshi et al. (2017), it has been
found that the recycled water from the plant provides positive impact on the assessed
categories. Effect of treatment system is overriding the effect of recycled water
in other categories like terrestrial ecotoxicity potential, global warming potential,
particulate matter formation, fossil depletion potential, etc. However, the social effect
of untreated sewer and environmental effect of compost produced by the system have
not been studied. This founding is also concurred with founding by Bhakar et al.
(2015) that the recycled water used for irrigation has nearly zero impact and the tap
water used in buildings has the highest impact on environment due to the extraction
of groundwater and its supply consumes a lot of energy.
Despite the variability and advantages of recycled water from sewage, there are
several concerns related to environmental and health risks. If not properly managed, recycled water could deteriorate soil health in terms of increased salinity and
solidicity, heavy metal accumulation, and decreased hydraulic conductivity of soil
(Rahman et al. 2016). Nevertheless, recycled water may contain undesirable chemical constituents and pathogens which may threaten the environmental and domestic
health (Papadopoulos 1995). A few risk factors have been identified due to the continuous usage of recycling wastewater which can be short and long term impacts
(WHO 1987).
For instance, the Hawkesbury campus of the University of Western Sydney
(UWS), with its strong agricultural and environmental ethos, has had an agreement with the Sydney Water Corporation to accept tertiary-treated (chlorinated but
A. Z. Yaser and N. N. Safie
by Bhakar et al. (2016), the impact of treated water on global warming potential is
negligible while the impact of fresh tap water has 77% impact and treated water used
for irrigation is the origin of 0.01% of the impacts only. The study also shows that
the use of treated water for gardening activities will reduce the environmental impact
of the university by almost 25%.
Wastewater recycling for irrigation is a potentially important as well as relatively
low-cost source of water and therefore is used in more than 40 countries (Jiménez
and Asano 2008). Instead of being used for irrigation, Ghangrekar et al. (2007) have
utilized a sewage pond for aquaculture, by releasing fish like tilapia into the pond.
Also, duckweed has been reproduced in the same sewage pond and has shown that
sewage pond is feasible for aquaculture activities.
Sewage generated from colleges and universities contain low heavy metal and
contaminants which make it suitable to be reused on-site for nonpotable uses such
as lawn irrigation and toilet flushing. Toilet flushing can be done in a compound
such as hotel as being done by March et al. (2004). The water is filtrated, treated,
and disinfected using hypochlorite as the disinfecting agent before it is being used in
toilet flushing system. An average amount of water of 5.2 m
3 /d
−1 was reused, which
represents 23% of the total water consumption of the hotel.
Instead of toilet flush system, analysis by Zhang et al. (2017) has shown that
bathing sewage is very suitable for the waste heat recovery by using sewage source
heat pump because of its suitable water flow, water temperature, and water quality.
Also, it is economically feasible with payback period 3.39 year. This is suitable to
be used to preheat the water bath in hostel shower rooms.
Based on the life cycle assessment (LCA) by Raghuvanshi et al. (2017), it has been
found that the recycled water from the plant provides positive impact on the assessed
categories. Effect of treatment system is overriding the effect of recycled water
in other categories like terrestrial ecotoxicity potential, global warming potential,
particulate matter formation, fossil depletion potential, etc. However, the social effect
of untreated sewer and environmental effect of compost produced by the system have
not been studied. This founding is also concurred with founding by Bhakar et al.
(2015) that the recycled water used for irrigation has nearly zero impact and the tap
water used in buildings has the highest impact on environment due to the extraction
of groundwater and its supply consumes a lot of energy.
Despite the variability and advantages of recycled water from sewage, there are
several concerns related to environmental and health risks. If not properly managed, recycled water could deteriorate soil health in terms of increased salinity and
solidicity, heavy metal accumulation, and decreased hydraulic conductivity of soil
(Rahman et al. 2016). Nevertheless, recycled water may contain undesirable chemical constituents and pathogens which may threaten the environmental and domestic
health (Papadopoulos 1995). A few risk factors have been identified due to the continuous usage of recycling wastewater which can be short and long term impacts
(WHO 1987).
For instance, the Hawkesbury campus of the University of Western Sydney
(UWS), with its strong agricultural and environmental ethos, has had an agreement with the Sydney Water Corporation to accept tertiary-treated (chlorinated but