Characterizing the Pequi Bark (Caryocar brasiliense Camb.) and Teak Sawdust (Tectona grandis) Biomasses in natura, or Modified with Citric Acid, According to Boehm's Methodology to Set the Basic and Acidic Groups

Abstract

Characterizing the Pequi Bark (Caryocar brasiliense Camb.) and Teak Sawdust (Tectona grandis) Biomasses in natura, or Modified with Citric Acid, According to Boehm's Methodology to Set the Basic and Acidic Groups Abstract: Water contamination by potentially toxic metals has become evident due to industrial and population growth. Such contamination has been leading to growing environmental and human health issues caused by the high toxicity of these metal species, even at low concentrations. The biosorption process is a low-cost and goodefficiency alternative for metallic species removal. Applying the methodology by Boehm, the present study aims at investigating the amount of basic and acidic groups found on the surface of pequi bark (Caryocar brasiliense Camb.) and teak sawdust (Tectona grandis) biomasses, in natura or modified through citric acid addition. In addition, the biosorption capacity of these biomasses was studied in the Cd(II) and Pb(II) ions aqueous solution. Both biomasses have basic and acidic groups on their surface. The biomass surface changes because the chemical treatment increases the amount of groups found on it. However, the teak sawdust biomass in natura showed larger number of basic groups than the modified sawdust biomass The biosorption study has shown the good biosorptive capacity of the biomasses.

EVALUATION OF THE BIOSORPTION OF Mn²⁺ AND Zn²⁺ BY PASSION FRUIT PEEL: STUDY OF DOSAGE AND CONTACT TIME

“…The functional groups present on the surface of the biosorbent play a fundamental role in the adsorption of metal ions in solution. As illustrated in Figure 2, the presence of acidic groups, such as lactonic, phenolic and carboxylic, gives the biomass surface an acidic and hydrophilic character (Nascimento & Oliveira, 2017). This leads to a decrease in pH until stabilization and an increase in surface charge density, facilitating the interaction of metal species dissolved in aqueous media.…”