Increase in Pb and Cd Adsorption by the Application of Peat in a Tropical Soil

Author(s)

Marques, Jessica Pelinsom ^[1] ; Silvestre Rodrigues, Valeria Guimaraes ^[1] ; Raimondi, Isabela Monici ^[1] ; Lima, Jacqueline Zanin ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Geotech Engn, 400 Trabalhador Saocarlense Ave, BR-13566590 Sao Carlos - Brazil

• Document type: Journal article
• Source: WATER AIR AND SOIL POLLUTION; v. 231, n. 3 MAR 16 2020.
• Web of Science Citations: 2

Abstract

Clayey soils have been used as liners at the base of waste deposits due to their geotechnical characteristics and capacity to adsorb metallic cations. However, a number of soils may not possess all required properties to ensure contaminant retention and therefore require additives. This study investigated whether the addition of commercial peat to a tropical residual soil (from the Ribeira Valley, Brazil) could improve its lead (Pb) and cadmium (Cd) adsorption capacity for its use as a liner in mining waste disposal. Pure soil and 10 and 20% soil-peat mixtures were compared. The application of peat increased the organic matter (OM) content (from 9 g kg(-1) in soil to 58 g kg(-1) in the 20% soil-peat mixture) and the cationic exchange capacity (CEC) (from 41.4 mmol(c) dm(-3) in soil to 143.1 mmol(c) dm(-3) in the 20% soil-peat mixture). Batch equilibrium test results revealed that the maximum Pb adsorption capacity of 623.6 mu g g(-1) also increased (to 1089.1 and 1270.0 mu g g(-1) in the 10 and 20% soil-peat mixtures, respectively). The soil Cd adsorption capacity of 261.2 mu g g(-1) increased to 304.0 and 631.3 mu g g(-1), respectively, with increasing peat proportions. The results suggest that peat can improve soil liner performance in waste deposits. Soil-peat mixtures are alternatives for minimizing potentially toxic metal contamination with available and low-cost materials. (AU)

• FAPESP's process: 15/02529-4 - Geological-geotechnical characterization of reactive organic materials to be used in the retention of potentially toxic metals
• Grantee: Jacqueline Zanin Lima
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/07180-7 - Study of the soil contamination degree in the area of the former mining plant Plumbum (Adrianópolis, PR) due to the disposal of mining waste
• Grantee: Valéria Guimarães Silvestre Rodrigues
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/17894-2 - Geological and geotechnical characterization of mixtures of residual soil from Eldorado Paulista (SP) with reactive organic materials
• Grantee: Jéssica Pelinsom Marques
• Support Opportunities: Scholarships in Brazil - Master