The acid–base, morphological and structural properties of new biosorbent obtained by oxidative hydrothermal treatment of peat

• Published in: Environmental earth sciences Vol. 75; no. 9; pp. 1 - 10
• Main Authors: Ranđelović, M., Momčilović, M., Purenović, M., Zarubica, A., Bojić, A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2016; Springer Nature B.V
• Subjects: Acids; Adsorption; Biogeosciences; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Geochemistry; Geology; Hydrology/Water Resources; Leaching; Organic matter; Original Article; Oxidation; Peat; Peatlands; Phenols; Terrestrial Pollution; Water pollution; Hydrothermal treatment; Acid–base properties; Peat; Surface
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-016-5242-0

Samples of natural peat (NP) were hydrothermally treated at different temperatures in oxidative and acidic aqueous medium to tailor their acid–base, adsorption, morphological and other properties. The obtained materials were thoroughly characterized by SEM, XRD and FTIR techniques, followed by determination of pH pzc , examination of adsorption characteristics and the extent of organic matter leaching in water. Acid–base characteristics of these materials were examined by potentiometric and conductometric titration of corresponding aqueous suspensions. Experimental potentiometric data were interpreted using ProtoFit software (NEM, non-electrostatic model) which provided p K a values and concentrations of surface sites which are compared with corresponding values obtained by conductometric titration method. There are two main types of surface groups (carboxylic and phenolic) that are dominant in the materials and determine their acid–base behavior in the aqueous medium. Temperature during oxidative hydrothermal treatment has no significant effect on the total number of surface groups, but influences the ratio of carboxylic and phenol-type groups. Hence, acid–base properties of peat can be tailored, which is useful in designing and improving adsorptive characteristics of peat for the preferential removal of certain pollutants from water.