A two-step biosorption methodology for efficient and rapid removal of Fe(II) following As(V) from aqueous solution using abundant biomaterials

An innovative methodology was implemented for removing arsenic from aqueous solution by developing successive biosorption experiments. Considering the high affinity of As oxyanions toward Fe(III) oxides, the biosorption of Fe(II) was first conducted using nine biomaterials-aquatic and terrestrial invasive species, biowastes, local plants. Pistia stratiotes, an invasive alien species presenting the highest concentration of adsorbed Fe(II), was selected for a detailed investigation of As(V) removal from wastewater. After oxidation of the biosorbent into Fe(III), it yielded to a 92% removal efficiency determined by GFAAS and an excellent maximum biosorption capacity of 5.1 mg.g(-1). The biosorbent was characterized by MP-AES and HRTEM-EDX. The adsorption mechanisms for iron and arsenic have been studied via theoretical models and the Langmuir isotherms and pseudo-second-order kinetics models revealed excellent linearity and highlighted the robustness of the method. These promising results were developed to build a pilot for As(V) removal from the Russec river (Orbiel Valley, France), polluted with arsenic.

Automated summary

An innovative methodology using successive biosorption experiments was implemented to remove arsenic from aqueous solution. Fe(II) biosorption was conducted using a variety of biomaterials, and Pistia stratiotes was chosen as the most effective for As(V) removal. After oxidizing the biosorbent into Fe(III), a 92% removal efficiency and a maximum biosorption capacity of 5.1 mg.g(-1) were achieved. The adsorption mechanisms for iron and arsenic were studied using theoretical models, and the Langmuir isotherms and pseudo-second-order kinetics models showed excellent linearity and robustness. These promising results have been applied to a pilot project for As(V) removal from the Russec river in the Orbiel Valley, France.