86
I. G. Breaban and A. I. Breaban
From an european perspective, the treatment of urban waste water registered an
increased trend, the connectivity to waste water treatment plants being different for
each region. Despite the case of the northern region, where from 1995 above 80%
of the population has access to treatment plants which receive in proportion of 70%
tertiary treatment, in the central countries a large part of the population (97%) is
currently integrated into the local waste water treatment system, from which 75%
benefits of tertiary treated water. In southern, south-eastern and eastern Europe the
proportion of the population connected to urban waste water treatment is generally
lower than in other parts of Europe but has increased over the last 10 years being at
a level of approximately 70% [61].
For Romania has been noticed a particular situation where almost half of the residents are not connected to sewage system, therefore waste water is directly transferred
to natural emissary. In addition, it is highlighted a slow continuous increase regarding
the beneficiaries of treated waste water from 40.2% (2005) to 47.8% (2015), from
which currently only 1.9% do not treat the collected waste waters. After the EU
accession in 2007, the primary/secondary/tertiary ratios are changed in the favour of
the last stage of treatment, prevailing the removing of the mainly nutrients (39:61:0
in 2005 to 14:32:54 in 2015).
3.3.1.3 Inorganic Pollutants
Inorganic pollutants are naturally present in the environment, but due to human
activities, the amount of pollutants released into water bodies has increased rapidly
over the past decades. The most common inorganic pollutants in the water are ions
derived from nutrients (ammonium, nitrate, phosphorus) or heavy metals (arsenic,
cadmium, zinc, lead, mercury, etc.) characterized by high toxicity to both the environment and humans (Table 3.3). Pollutants like ammonia and phosphorus potentiate
the eutrophication process, excessive amounts of pollutants released into the water
can accelerate this phenomenon in a few years, while heavy metals such as arsenic
can cause skin, lung, bladder and kidney cancer, as well as changes in pigmentation,
skin thickening (hyperkeratosis) neurological disorders, muscle weakness, loss of
appetite and nausea (Fig. 3.22).
3.3.1.4 Nutrients
Agricultural run-off, wastewater from the fertilizer and wastewater industry contains
a substantial concentration of nutrients such as nitrogen and phosphorus. These
drinking water supplies plants can have effects stimulating the growth of algae and
other undesirable aquatic plants in the natural receptors, leading to the degradation
of these bodies of water. In the long run, the body of water reduces the amount of
dissolved oxygen, experiencing eutrophication and dead water [25, 43, 104, 105,
120, 132].
I. G. Breaban and A. I. Breaban
From an european perspective, the treatment of urban waste water registered an
increased trend, the connectivity to waste water treatment plants being different for
each region. Despite the case of the northern region, where from 1995 above 80%
of the population has access to treatment plants which receive in proportion of 70%
tertiary treatment, in the central countries a large part of the population (97%) is
currently integrated into the local waste water treatment system, from which 75%
benefits of tertiary treated water. In southern, south-eastern and eastern Europe the
proportion of the population connected to urban waste water treatment is generally
lower than in other parts of Europe but has increased over the last 10 years being at
a level of approximately 70% [61].
For Romania has been noticed a particular situation where almost half of the residents are not connected to sewage system, therefore waste water is directly transferred
to natural emissary. In addition, it is highlighted a slow continuous increase regarding
the beneficiaries of treated waste water from 40.2% (2005) to 47.8% (2015), from
which currently only 1.9% do not treat the collected waste waters. After the EU
accession in 2007, the primary/secondary/tertiary ratios are changed in the favour of
the last stage of treatment, prevailing the removing of the mainly nutrients (39:61:0
in 2005 to 14:32:54 in 2015).
3.3.1.3 Inorganic Pollutants
Inorganic pollutants are naturally present in the environment, but due to human
activities, the amount of pollutants released into water bodies has increased rapidly
over the past decades. The most common inorganic pollutants in the water are ions
derived from nutrients (ammonium, nitrate, phosphorus) or heavy metals (arsenic,
cadmium, zinc, lead, mercury, etc.) characterized by high toxicity to both the environment and humans (Table 3.3). Pollutants like ammonia and phosphorus potentiate
the eutrophication process, excessive amounts of pollutants released into the water
can accelerate this phenomenon in a few years, while heavy metals such as arsenic
can cause skin, lung, bladder and kidney cancer, as well as changes in pigmentation,
skin thickening (hyperkeratosis) neurological disorders, muscle weakness, loss of
appetite and nausea (Fig. 3.22).
3.3.1.4 Nutrients
Agricultural run-off, wastewater from the fertilizer and wastewater industry contains
a substantial concentration of nutrients such as nitrogen and phosphorus. These
drinking water supplies plants can have effects stimulating the growth of algae and
other undesirable aquatic plants in the natural receptors, leading to the degradation
of these bodies of water. In the long run, the body of water reduces the amount of
dissolved oxygen, experiencing eutrophication and dead water [25, 43, 104, 105,
120, 132].