1Нийгмийн эрүүл мэндийн үндэсний төв, 2Монголын анагаах ухааны академи
Introduction
According to the report from 2010, Mongolian water consumption was 550 million cubic meter and approximately 9.1% of the total Mongolian population obtain their water from inadequate hygiene water resources - springs and rivers. Due to non-hygiene water usage has caused water-born communicable and non communicable diseases among the population. In the last years there has been issue of pollution of one of the Mongolia’s more representative river Selenge and its following rivers -Kharaa, Orkhon and it is necessary to evaluate water pollution of these rivers.
Goal
To determine water chemical and biological pollution of Kharaa and Orkhon river and to evaluate water quality
Materials and Methods
We collected water, sediments and macro invertebrates sample from three points of river -upstream, midstream, downstream and for Kharaa river the samples were collected from Tunkhel, Mandal and Bayangol soum, fo Orkhon river the sequence was Orkhontuul, Orkhon, Khushaat soum. Samples were collected June, August, October of 2011, 2013.
In water sample, we determined physic-chemical 15 parameters including temperature, pH, total dissolved solids, conductivity, smell, color, hardness, sulfate, chloride, nitrate, nitrite, ammonia, dissolved oxygen, biological oxygen demand and mercury using their standard methods. Macro invertebrate samples were collected to evaluate water quality and we determined mercury in sediments and macroinvertebrate samples to evaluate mercury contamination.
Result
Physic-chemical results of the water showed that water of Kharaa, Orkhon rivers were classified low mineralized, soft water and nutrient pollution indicators for ‘slightly polluted’category. For dissolved and biochemical oxygen, they were belong to the category of ‘pure water’. There were no correlation between 2012 and 2013 results and mercury in water, sediments and macro invertebrates were qualified standard value.
Conclusion
According to research results water quality of Kharaa, Orkhon river was good and have less pollution and it is possible to use in household consumption after proper cleaning and disinfection.
Key word: Water quality, chemical and liological pollution
Pp. 25-29, Table 1, Figures 8, References 6