The demand for clean and hygienic water is always a top
concern and has become a strategy of many countries including
Vietnam. Currently, the living standard in our country is being
improved gradually, awareness of health protection is increasing,
especially in big cities like Hanoi. This is the second most populated
area in the country with a population of about 7 million people in
2014. However, along with the development of many aspects of the
capital, the issue of clean water access has not been met in both
quantity and quality.
The survey results of the Northern Hydrogeological –
Engineering Geological Division showed that the ammonia
concentration in groundwater in Hanoi has exceeded many times
compared to the permitted standards, in which some places are 10-20
times higher.
The biggest concern about ammonia is that the intermediates
such as nitrite and nitrate compounds are formed from ammonia in
the treatment process and use of water for domestic and drinking
purposes under the following mechanism: During the water
treatment process, there always formed naturally Nitrosomonas
bacteria in the filtration tank, which converts part of the ammonia in
groundwater into nitrite intermediates. With sufficient conditions,
under action of a different type of bacteria that is naturally formed in
the filtration tank as Nitrobacter, the nitrite intermediates will be
further transformed into nitrate. While there is insufficient evidence
to assess the extent and direction of the effects of ammonia-based2
products on the human body, the harm caused by NO2-, NO3- is
well known. NO2-, NO3- are the agents that cause red blood cell
damage in children and may be cancer-causing agents