Investigation of physical and chemical quality of surface water and sediment in seven locations from Danube Delta, in the period 2009-2011

The purpose of this paper was to investigate distribution of organic and inorganic contamination in water and sediment in different locations of Saint George Branch -the southern branch of the Danube Delta. Concentrations of dissolved oxygen, nutrients, metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), mineral oil were analyzed in water and sediment samples and the results were compared to those obtained in the previous works. Sampling was monthly performed in the period 2009-2011 from seven locations of Saint George Branch from the Danube Delta. The obtained values were evaluated for their compliance with quality standards stipulated in Statutory Order No. 161/2006 of the Romanian Ministry of the Environment and Water Management. In Danube river water, the content of heavy and toxic metals was in most cases below the limits according to the national legislation, only iron values exceed the limit. Concerning organic compounds, mineral oil, DDTs and PCBs periodically were recorded in river water over the limit. In sediment, in some locations, were detected higher concentrations of copper, nickel, mercury, Lindane, PAHs, DDTs and PCBs that exceeded the quality standards according to Romanian legislation transposed from Frame Water Directive 2000/60/EC.