Selected element concentrations in alluvial sediments under garbage disposal site (Zagreb, Croatia)

• Published in: Water research (Oxford) Vol. 31; no. 6; pp. 1421 - 1429
• Main Authors: VERTACNIK, A, PROHIC, E, JURACIC, M, BARISIC, D, LULIC, S
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.1997; Elsevier Science
• Subjects: alluvial sediment; correlations; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; enrichment factor; Exact sciences and technology; garbage disposal site; Geochemistry; INAA; OES; Pollution, environment geology; Soil and rock geochemistry; trace elements; Southern Europe; Croatia; alluvial sediment; garbage disposal site; trace elements; Ag; enrichment factor; INAA; OES; correlations; illite; trace metals; oxides; waste disposal; cation exchange capacity; heavy metals; ground water; pollution; specific surface; mineral assemblages; enrichment; aquifers; human waste; sheet silicates; silicates; alluvium; Europe; strontium; chlorite; carbonates; chemical analysis; industrial waste; contamination; oxihydroxides; granulometry; correlation; organic materials; clay minerals; iron; silver; sediments
• DOI: 10.1016/S0043-1354(96)00346-6
• ISSN: 0043-1354

Ag, Ba, Cd, Ce, Cs, Co, Cr, Cu, Eu, Fe, Ga, Mn, Ni, Pb, Rb, Sb, Sc, Sr, Th, Ti, V, Zn and Zr concentrations in alluvial sediments were determined by INAA and OES in the area used as a garbage disposal site in the vicinity of a water-well field. Results show that total concentrations of analysed elements depend on sediment characteristics: mineral composition, specific surface area, cation exchange capacity, organic matter and clay-grain size fraction content. On the other hand, concentrations in sediment depend on physico-chemical forms and geochemical characteristics of the elements in question. Most of the elements reveal excellent/very good correlations with iron, while strontium shows negative correlation with iron. Strontium has a very good, positive correlation with carbonate content, while all other analysed elements, except silver, have excellent negative correlations with carbonates. Correlations with clay-grain size fraction are good or very good for all elements, except strontium and silver. The only element which is not correlated, either with iron, carbonate, or with clay-grain size fraction is silver. One can conclude, therefore, that silver is introduced as discrete particles. Extremely high silver concentration was found 6.5–6.8 m below the garbage in the aerated layer, occasionally under the water table. The enrichment factor for silver is found to be 127, which is a clear indication of sediment pollution with silver. Long-lasting clandestine deposition of industrial wastes on a disposal site meant for domestic wastes might be the reason. The elevated concentrations found on the 11.2–11.4 m depth are concordant with mineralogical composition (MnO-hydroxides, iron minerals, illite, chlorite) and enrichment factors for the majority of analysed elements are below 2. For the time being, this sediment layer acts as a chemical filter preventing infiltration in the vertical direction. Concentrations and enrichment factors of all determined elements from the uppermost and deeper water bearing layers are of natural values. Taking into account these, and additional, piezometer results, it can be concluded that the quality of water taken from the water-well field downstream of the garbage disposal site is not endangered so far.