Sources and causes of surface water pollution in Hanoi (Vietnam)

Introduction. One of the most significant environmental problems facing the Vietnamese city of Hanoi is anthropogenic pollution of surface water, especially in the To Lich river system. Currently, these rivers accept large quantities of wastewater from urban areas and industrial zones, which effluents are not treated prior to discharge into water bodies. The results of the study show that surface water in Hanoi has been contaminated by direct discharge of domestic and industrial wastewater. Considered the To Lich river system, including the To Lich, Lu, Set and Kim Nguu rivers, which receive sewage pollution from urban areas, industrial zones and other sources. Materials and methods. The most common approach to improving the situation is to identify sources of syrface water pollution and assess the quality of To Lich river and its tributaries in order to develop and propose effective and synchronous solurion for the management of water safety and quality in the water bodies of Hanoi city. The water samples were preserved and analysed in the laboratory of Environmental Analysis in accordance with standard Vietnamese methods. For this purpose, analytic apparatus, including Shimadzu AAS 6800 atomic absorption spectrophotometre (Japan), UV-VIS spectrometre, as well as a number of common laboratory instruments and equipment, are used. Results. The results of the study show that surface water in Hanoi has been contaminated by direct discharge of domestic and industrial wastewater. For many years, the rivers have been covered with rubbish, with the water turning black in colour and having an unpleasant smell. The primary cause of the pollution is drainage from many surrounding households discharging waste water directly into the rivers. Conclusions. In order to restore the aqueous ecosystems of Hanoi city, it is necessary to conduct continuous environmental monitoring of changes in the state of water bodies and develop effective and timely solutions for the management of safety and quality of water in the waterways of Hanoi.