Biosurface properties and lead adsorption in a clone of Sphagnum palustre (Mosses): Towards a unified protocol of biomonitoring of airborne heavy metal pollution. (December 2019)

• Record Type: Journal Article
• Authors: Di Palma, Anna; González, Aridane G.; Adamo, Paola; Giordano, Simonetta; Reski, Ralf; Pokrovsky, Oleg S.
• Is Part Of: Chemosphere. Volume 236(2019)
• Publication Date: 2019-12
• Subjects: Biosorption -- Peat moss -- Langmuir isotherm -- Moss-bags -- Kinetics -- Heavy metals; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124375
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Although mosses are widely used for active biomonitoring of air pollution, a unified protocol for their treatment before exposure in bags is still lacking. Here we used field- and laboratory-grown Sphagnum palustre L. moss, respectively, treated by EDTA and devitalized by oven drying at 100 °C, to elaborate a consistent procedure of metal and proton adsorption on moss surfaces. Acid-base titrations and Pb 2+ adsorption experiments at different pH values and Pb 2+ concentrations in solution were performed with both field-collected and laboratory cloned mosses. Devitalization and EDTA treatments did not produce any measurable difference in terms of H + and Pb 2+ adsorption capacities of moss surfaces. The stability constants for Pb 2+ adsorption onto moss surfaces as a function of pH (pH-dependent adsorption edge) and at constant pH (5.5 and 6.5) as a function of Pb 2+ concentration ("langmuirian" adsorption isotherm) were rather similar between different treatments. A Linear Program Modeling (LPM) of adsorption reactions revealed high similarity of adsorption constants regardless of treatments for both field-grown and cloned mosses. Therefore, in view of the use of S. palustre clone for biomonitoring lead in the environment, we recommend devitalization at 100 °C as unique treatment to perform with the aim to preserve the biomonitor before and after its exposure in bags. Graphical abstract: Image 1 Highlights: Surface properties and Pb 2+ adsorption ability of a cloned moss were investigated. Clone and conspecific field-grown moss displayed comparable adsorption constants. EDTA-treated clone had the highest negative surface charge and the lowest pHPZC . EDTA washing did not affect the ability of cloned moss to adsorb Pb 2+ . Oven-devitalization is proposed as unique treatment for clone to use as biomonitor.