Determination of Cr(VI) in environmental samples evaluating Cr(VI) impact in a contaminated area.

Spectrophotometric determination of Cr +6 (using 1.5-diphenyl carbazide), in aqueous, sediment and soil samples is reported. Different leaching reagents like 0.5M NaOH-0.28M Na2CO3 and 0.2 M H3PO4 were used for the isolation of Cr +6 from sediment and soil samples. Determination of Cr 6 by using 0.5M NaOH-0.28M Na2CO3 as leaching reagent followed by spectrophotometric measurements provided satisfied results. The optimum experimental parameters of the reactions have been studied and the validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. Total Cr concentration was analyzed by AASF technique. This paper explores the development and application of Cr 6 chemical speciation in a polluted area and marine environment. The polluted site of Porto Romano, Durres, pointed as "Hot Spot Pollution" from UNEP/MAP (1992) was under investigation. The content of Cr +6 in soil and surface water samples inside territory of polluted site is very high (some g/kg in soil samples and arrived up to 130 mg/l in surface water samples). More than 90% of Crtot belongs to its easy so lub le for m and on ly 2−10% of it belongs to the form bounded with soils. The content of Cr +6 in seawater (about 0.04 mg/l) and sediment (5-6 mg/kg as Crtot) samples resulted within the normal levels. Only 11 to 13% of Crtot belongs to its easy so lub le for m and most of it (87−89%) belongs to the form bounded with sediments.