ở các thành phố lớn , đông dân chất thải do sinh hoạt cũng là một nguyên nhân quan trọng đang gây ô nhiễm môi trường nước .Ô nhiễm nước do sản xuất công nghiệp là rất nặng
in large cities, waste populated by living well is an important cause is causing water pollution. Water pollution caused by industrial production is very heavy
in big cities, populated by domestic waste is also an important cause of environmental pollution is causing water contamination by water .O industrial production is very heavy