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Chapter 10
Pollution Control Technology
Today, the techniques for the control of various pollution forms constitute a
complex advanced technology with great possibilities. Pollution control can
be achieved by methods aiming either at the decrease of generated pollutants, i.e. through preventive action, or at better treatment and disposal of
generated pollutants, i.e. through repressive action. Some facts in relation
to the technologies for dealing with pollution caused by liquid, gas, and
solid waste are discussed here.
10.1 DEALING WITH WATER POLLUTION
Various systems for treatment and disposal of wastewater are used in dealing with water pollution from the liquid waste of cities.
Liquid waste (wastewater) of cities is usually collected by a subterranean
drainage network (sewerage network) and conveyed to a facility where
it undergoes the proper treatment for each case. Disposal comes next,
i.e. wastewater is dumped into an aquatic receptor which can be the sea,
a river or current, a lake, the subsoil or underground water. Wastewater
may be directly reused, e.g. for irrigation. In some developed countries, the
separation of wastewater into “black” and “grey” is promoted by the use
of separate networks. The black wastewater corresponds to the more burdened liquid waste, e.g. from toilets, while the grey wastewater corresponds
to liquid waste, e.g. from washing machines, which is easier to reuse.
The kind and degree of treatment of the cities’ liquid waste depend on
the characteristics of the receptor or the kind of reuse. A minimum required
treatment, as a rule, is the greater or smaller removal of suspended solids
and organic matter (BOD, biochemical oxygen demand). Those removals
take place in primary treatment units and can be followed by secondary
treatment units.
In Figure 10.1 various treatment stages are depicted; the required degree
of treatment can be achieved through a proper combination of the stages.
The primary treatment stage usually includes screens, sand and grease
DOI: 10.1201/b14609-10
Chapter 10
Pollution Control Technology
Today, the techniques for the control of various pollution forms constitute a
complex advanced technology with great possibilities. Pollution control can
be achieved by methods aiming either at the decrease of generated pollutants, i.e. through preventive action, or at better treatment and disposal of
generated pollutants, i.e. through repressive action. Some facts in relation
to the technologies for dealing with pollution caused by liquid, gas, and
solid waste are discussed here.
10.1 DEALING WITH WATER POLLUTION
Various systems for treatment and disposal of wastewater are used in dealing with water pollution from the liquid waste of cities.
Liquid waste (wastewater) of cities is usually collected by a subterranean
drainage network (sewerage network) and conveyed to a facility where
it undergoes the proper treatment for each case. Disposal comes next,
i.e. wastewater is dumped into an aquatic receptor which can be the sea,
a river or current, a lake, the subsoil or underground water. Wastewater
may be directly reused, e.g. for irrigation. In some developed countries, the
separation of wastewater into “black” and “grey” is promoted by the use
of separate networks. The black wastewater corresponds to the more burdened liquid waste, e.g. from toilets, while the grey wastewater corresponds
to liquid waste, e.g. from washing machines, which is easier to reuse.
The kind and degree of treatment of the cities’ liquid waste depend on
the characteristics of the receptor or the kind of reuse. A minimum required
treatment, as a rule, is the greater or smaller removal of suspended solids
and organic matter (BOD, biochemical oxygen demand). Those removals
take place in primary treatment units and can be followed by secondary
treatment units.
In Figure 10.1 various treatment stages are depicted; the required degree
of treatment can be achieved through a proper combination of the stages.
The primary treatment stage usually includes screens, sand and grease
DOI: 10.1201/b14609-10