Mobility and Bioavailability of Heavy Metals and Metalloids in Soil Environments

Abstract

In soil environments, sorption/desorption reactions as well as chemical complexation with inorganic and organic ligands and redox reactions, both biotic and abiotic, are of great importance in controlling their bioavailability, leaching and toxicity. These reactions are affected by many factors such as pH, nature of the sorbents, presence and concentration of organic and inorganic ligands, including humic and fulvic acid, root exudates, microbial metabolites and nutrients. In this review, we highlight the impact of physical, chemical, and biological interfacial interactions on bioavailability and mobility of metals and metalloids in soil. Special attention is devoted to: i) the sorption/desorption processes of metals and metalloids on/from soil components and soils; ii) their precipitation and reduction-oxidation reactions in solution and onto surfaces of soil components; iii) their chemical speciation, fractionation and bioavailability.

Heavy metal contents in Latosols cultivated with vegetable crops1

“…There is a clear relationship between Ni and organic matter content in forest areas (L5 and S5). This is due to the high affinity of Ni for organic compounds, such as fulvic and humic acids (Smith 2009, Violante et al 2010.…”

Environmental mobility of trace elements present in dusts emitted from Zn–Pb metallurgical processes

“…Arsenic in natural waters and soils is closely related to the presence of iron (hydr)oxides being arsenate and arsenite strongly sorbed onto the surfaces of Fe oxides, forming inner-sphere complexes. The simultaneous presence of high dissolved As and Fe(II) concentrations in anoxic groundwater has led to the conclusion that reductive dissolution of As rich Fe(III) (hydr)oxides mobilises geogenic As (Borch et al 2010, Voliante et al 2010 The plotted Eh and pH diagrams indicate that within the pH range of 4.5-7.5, which is characteristic of the soil and water environment of the area under study, the mobile forms of arsenic in this environment include HAsO 3-, HAsO 4 2-, H 2 AsO 4 -. Under these conditions tin occurs in the stable form of SnO 2 .…”

Metales pesados en suelos y sedimentos de la zona cañera del sur de Quintana Roo, México

“…Cada interacción química les confiere diferente comportamiento físico y químico, modificando así su movilidad, disponibilidad biológica y toxicidad. Al mismo tiempo, estos factores pueden ser afectados por las propiedades fisicoquímicas del suelo como la variación en el pH (siendo éste el más importante en la disposición de los MP), el contenido de materia orgánica (MO), la capacidad de intercambio catiónico (CIC) y la textura (FAR y PPIC, 1988;De Matos et al, 2001;Dube et al, 2001;Violante et al, 2010;Sherene, 2010;Kennou et al, 2015). Cuando los MP están disueltos en agua, la conductividad hidráulica resultante de la humedad y la porosidad del suelo, pueden influir directamente en la movilidad.…”

“…Se ha reportado que en el suelo la CIC y la MO juegan un papel importante en la retención de los MP y el pH en la disposición de éstos, y por ello, concentraciones altas de MP se relacionan con estos parámetros (De Matos et al, 2001;Dube et al, 2001;Clemente et al, 2008;Violante et al, 2010;Kennou et al, 2015;Chandrasekaran y Ravisankar, 2015). En cultivos de caña de azúcar se recomiendan productos como Algaenzims® y Amikrone® para mejorar las propiedades físicas, químicas y biológicas del suelo y ayudar en la retención de los nutrientes.…”