Remediation of metal-contaminated soils with the addition of materials – Part II: Leaching tests to evaluate the efficiency of materials in the remediation of contaminated soils

Abstract

The effect of the addition of materials on the leaching pattern of As and metals (Cu, Zn, Ni, Pb, and Cd) in two contaminated soils was investigated. The examined materials included bentonites, silicates and industrial wastes, such as sugar foam, fly ashes and a material originated from the zeolitization of fly ash. Soil + material mixtures were prepared at 10% doses. Changes in the acid neutralization capacity, crystalline phases and contaminant leaching over a wide range of pHs were examined by using pH(stat) leaching tests. Sugar foam, the zeolitic material and MX-80 bentonite produced the greatest decrease in the leaching of pollutants due to an increase in the pH and/or the sorption capacity in the resulting mixture. This finding suggests that soil remediation may be a feasible option for the reuse of non-hazardous wastes.

Removal of Chromium from a Contaminated Soil Using Oxalic Acid, Citric Acid, and Hydrochloric Acid: Dynamics, Mechanisms, and Concomitant Removal of Non-Targeted Metals

“…The original soil was characterized by the main mineral quartz, as well as other minor minerals, such as orthoclase, tamarugite, albite, microcline, zeolite and other silicate minerals (Figure 4a). Previous results have found several soil crystalline phases, particularly calcite, vermiculite and illite, can rapidly and fully dissolve under low soil pH conditions [33,34]. In our present study, on one hand, some diffraction peaks disappeared after leaching, suggesting the removal of some phases by the acids.…”

Stabilisation of Pb in Pb Smelting Slag-Contaminated Soil by Compost-Modified Biochars and Their Effects on Maize Plant Growth

“…The soil Pb levels in soil amended with higher rates (200 g/500g) of compost and amendments were the least. This perhaps was due to dilution effect which high rate of amendment could produce on the contaminant in soil [25]. However, this high application rate may not be applicable in real field conditions.…”

Low-grade magnesium oxide by-products for environmental solutions: Characterization and geochemical performance

“…It is also directly related to its specific surface area and particle size distribution (Demir et al, 2006). The acid-base properties of solid wastes have been found to considerably influence the leaching of solid wastes by changing the pH environment (González-Núñez et al, 2012;Yan et al, 2000). The pH environment of the system can be defined by the buffering capacity, which is usually measured by means of the acid neutralization capacity (ANC) test (CEN 14997).…”