Author(s): MARQUES, J. P.; VAZ, C. M. P.; SÍGOLO, J. B.; RODRIGUES, V. G. S.

Summary: In waste disposal areas, soils can be used as environmental protection barriers to retain potentially toxic metals. Although most studies focus on lateritic soils, it is still of interest to evaluate other soil types, aiming to select the best materials among those available near the contamination area, reducing costs and construction efforts. This paper characterizes and evaluates the behavior of 13 soil materials collected in a region (Ribeira Valley, Brazil) with a history of improper mining waste disposal for the retention of lead (Pb) and cadmium (Cd) and their possible use as environmental protection barriers. All soils were acidic, kaolinitic, with negatively charged particles. Soils were grouped into three classes according to soil properties, such as particle size distribution, cation exchange capacity (CEC), and specific surface area (SSA), using cluster and principal component analysis. The Pb and Cd adsorption capacities ranged from 288 to 479 µg g?1 and 207 to 326 µg g?1, respectively, obtained from batch equilibrium tests. In general, all soils presented suitablecharacteristics for the retention of Pb and Cd, but four of them (1 to 4) showed the highest adsorptioncapacities, probably due to their larger SSA, CEC and percentage of fines (clay + silt).

Publication year: 2022

Types of publication: Journal article

Unit: Embrapa Instrumentation

Keywords: Batch equilibrium tests, Contamination, Potentially toxic metals