Scopul nostru este sprijinirea şi promovarea cercetării ştiinţifice şi facilitarea comunicării între cercetătorii români din întreaga lume.
Autori: Emil A. Cordos, Tiberiu Frentiu, Michaela Ponta, Ioan Marginean, Bela Abraham, Cecilia Roman
Editorial: Chemical speciation and Bioavailability, 18 (1), p.11-25, 2006.
Baia-Mare industrial site in NW Romania was investigated to assess the distribution, speciation and mobility of inorganic arsenic species in soil. Contents and fractions of As(III), As(V) and total As leachable in water, 1M HCl and 10M HCl were determined in soil by single extraction. Total arsenic content in the selected sample, determined after a matrix modification with Mg(NO3)2 was in the range 10–1725 mg/g. The contents (mg/g) of leachable As (III) As (V) species by single extraction were: 0.1–70 (0.8–950) in water, 0.2–90 (1.6–1200) in 1M HCl and 0.8–100 (8–1500) in 10M HCl, showing that arsenic (V) species represented more than 90% of the total. Leaching tests indicated a high availability of arsenic in water, although poorly reactive phases were encountered as well. Compared to the total arsenic in soil, fractions of 9–34% were leachable in water, 39–80% in 1M HCl and 77–94% in 10M HCl. Contamination was higher at the surface than at depth and decreased with the distance from the pollutant source. Centres for pyrometallurgical processing of ores are mainly responsible for pollution with water soluble species, while centres for ores concentration for pollution with poorly reactive arsenic species soluble in 10M HCl and Mg(NO3)2. According to the sequential extraction data, soils in the area could be divided into three categories according to its maximum mobility in water, 1M HCl and 10M HCl. Good precision (RSD 7.5–17.6%) and recovery degree (101+-3%) were achieved for arsenic determination in five certified soils (n = 5).
Cuvinte cheie: inorganic arsenic speciation, soil contamination, single extraction, hydride generation, atomic absorption spectrometry