Emerging Water Pollutants and Wastewater Treatments
33
It should be noted that 80–90% of the BODs, suspended solids SS and some of
the high-density metals initially present in the raw wastewater are been removed
during the biological treatment process coupled with primary sedimentation. A little
higher quality effluent can be produced from the activated sludge process particularly
when disinfection units are coupled with the system. This method gives substantial but incomplete virus and bacteria removal. However, dissolved minerals, nonbiodegradable organics, nitrogen or phosphorus are removed in small quantities in
the system.
(d) Effluent storage
Storage facilities are in most cases links between the irrigation system and the
wastewater treatment plant. However, storage is of great need so as:
i. To establish the deviations in daily flow from the plants and to keep excess
wastewater when the average flow of wastewater goes beyond irrigation
demands (including winter storage).
ii. To keep up with the maximum irrigation demands when influence flow is
moderate.
iii. To reduce the effect of interruptions in the irrigation system and treatment plant
operations. Storage also provides extra time to address temporary water quality
challenges and provides insurance against the chances of unsuitable reclaimed
wastewater entering the irrigation system.
iv. To make wastewater available for advanced treatment. Nitrogen, oxygen
demands, microorganisms, and suspended solids may reduce during storage.
9 Challenges
In an attempt to solve the problems and challenges of emerging water pollutants,
there are needs to focus attention on the following areas:
i.
Treating nano-pollutants has remained a big problem to the currently used
wastewater treatment technologies.
ii.
Water reclamation in form of reuse and recycling should be promoted both in
the short and long term.
iii. Basic and fundamental standards of wastewater reclamation should be established; these will include marking/classification of wastewater and the purpose
and benefits of re-use.
iv.
An established basis for large-scale wastewater reclamation should be put in
place when wastewater treatment plants are established.
v.
Treatment plants for wastewater in rural areas are both scarce and hardly
in existence. This should be given priority attention to prevent water-borne
diseases.
vi. In rural areas, facilities for decentralized wastewater treatment should be put in
place; this will bring about resource/energy recovery from sludge generated.
33
It should be noted that 80–90% of the BODs, suspended solids SS and some of
the high-density metals initially present in the raw wastewater are been removed
during the biological treatment process coupled with primary sedimentation. A little
higher quality effluent can be produced from the activated sludge process particularly
when disinfection units are coupled with the system. This method gives substantial but incomplete virus and bacteria removal. However, dissolved minerals, nonbiodegradable organics, nitrogen or phosphorus are removed in small quantities in
the system.
(d) Effluent storage
Storage facilities are in most cases links between the irrigation system and the
wastewater treatment plant. However, storage is of great need so as:
i. To establish the deviations in daily flow from the plants and to keep excess
wastewater when the average flow of wastewater goes beyond irrigation
demands (including winter storage).
ii. To keep up with the maximum irrigation demands when influence flow is
moderate.
iii. To reduce the effect of interruptions in the irrigation system and treatment plant
operations. Storage also provides extra time to address temporary water quality
challenges and provides insurance against the chances of unsuitable reclaimed
wastewater entering the irrigation system.
iv. To make wastewater available for advanced treatment. Nitrogen, oxygen
demands, microorganisms, and suspended solids may reduce during storage.
9 Challenges
In an attempt to solve the problems and challenges of emerging water pollutants,
there are needs to focus attention on the following areas:
i.
Treating nano-pollutants has remained a big problem to the currently used
wastewater treatment technologies.
ii.
Water reclamation in form of reuse and recycling should be promoted both in
the short and long term.
iii. Basic and fundamental standards of wastewater reclamation should be established; these will include marking/classification of wastewater and the purpose
and benefits of re-use.
iv.
An established basis for large-scale wastewater reclamation should be put in
place when wastewater treatment plants are established.
v.
Treatment plants for wastewater in rural areas are both scarce and hardly
in existence. This should be given priority attention to prevent water-borne
diseases.
vi. In rural areas, facilities for decentralized wastewater treatment should be put in
place; this will bring about resource/energy recovery from sludge generated.