Sorption of heavy metals in organic horizons of acid forest soils at low added concentrations

Abstract

Vytopilová M., Tejnecký V., Borůvka L., Drábek O. (2015): Sorption of heavy metals in organic horizons of acid forest soils at low added concentrations. Soil & Water Res., 10: 1-9.The individual adsorption/desorption of Cu, Pb, and Zn in six soil samples taken from organic horizons of acid forest soils is studied in batch experiments. These three metals were chosen because of the varying extent of their sorption to the soil organic matter. The initial concentration range for all metals is 0-200 mg/l. 0.01 mol/l Ca(NO 3 ) 2 was used as the background electrolyte. Soil samples were taken at random locations throughout a relatively small area and are characterized by small differences in mineralogical composition. Organic matter content and pH of soils are considered as the key factors causing differences in sorption/desorption behaviour of selected metals. In general, the sorption of all the three metals increased with a combination of higher pH value and increasing organic matter content. Anyway, the extent of the influence of these two characteristics on sorption behaviour of metals is different, for desorption significant differences were not determined. Copper sorption seems to reflect mainly the differences in organic matter content in addition to the differences in pH. The average amount of sorbed Pb was approximately 90%, Cu sorption averaged 60%, and that of Zn 30%. Desorption of Pb into 0.01 mol/l Ca(NO 3 ) 2 remained at approximately 4%, for Zn at 30%, and desorption of Cu reached up to 13% of the amount adsorbed. All the studied soils proved effective at immobilizing lead and copper, but zinc was relatively highly released from these soils, even when the sorbed amount was minimal. Different vegetational background of these samples (either beech or spruce forests) does not significantly influence the sorption extent of these metals as the lower pH of samples taken under spruce stands is probably compensated by higher organic matter content in these samples. The experimental data are fitted by the Freundlich equation and the parameters of this equation together with the adsorption and desorption efficiency are used for comparison of the behaviour of all the three metals among the six soils.

The effective removal of heavy metals from water by activated carbon adsorbents of Albizia lebbeck and Melia azedarach seed shells

“…Over the last few decades, activated carbon have been extensively applied as a potent adsorbent for the expulsion of poisonous metals from wastewater due to the tunable surface chemistry and well-developed permeable structure with a high specific surface area. The selection of carbon as an adsorbent is, therefore, extremely significant as heavy metals are removed through complexation or by electrostatic attraction between the metal ions and different oxygen carrying functional groups present on the surface of the activated carbon adsorbents (Mahaninia et al 2015;Vytopilová et al 2015;Burakov et al 2018;Huang et al 2018).…”

Vertical Migration of Copper and Zinc Ions in Soils Polluted by Electroplating Sludge

“…The ability of soil to adsorb PTM increases with increasing cation exchange capacity. [ 16,17,33 ] Thus, Gleyic chernozem and Typical heavy black soil, which are characterized by heavy texture and high humus content, have a relatively high cation exchange capacity ( E = 16.3 mol/100 g) (Table 1). However, the adsorbing process is more intensive in Mollic gleyic fluvisol (Figure 1) in comparison with Typical heavy black soil due to the higher content of clay (2.2‒2.4 times more) and humus (1.3 times more) (Table 1).…”

“…In several studies [ 16–21 ] the content of organic matter and soil pH was determined as key factors causing differences in the sorption—desorption of PTMs. For example, potassium humate is known to be an effective stabilizer of metals, although it has an insignificant effect on the reduction of Cu bioavailability.…”

Comparison of Models for Spatial Distribution and Prediction of Cadmium in Subtropical Forest Soils, Guangdong, China

“…The average natural abundance of Cd in the Earth's crust is normally reported to range from 0.1 to 0.5 mg kg −1 across the world [14][15][16], with some exceptions: some reports indicate a significant percentage increase in various soils, with up to 25 mg kg −1 detected in soil derived from sedimentary rocks. These variations may be attributed to many factors, such as climatic, topographic, ecological, soil, and biological conditions.…”