Periphyton biofilms formulation and application for the removal of trace pollutants from water

Abstract

Freshwater resource contamination with trace metals (TMs) poses a major risk to public health and the ecosystem. In the current study, three distinct types of periphyton biofilms (PPBFs)—epiphyton, epilithon, and metaphyton—were cultured and employed to remove TMs from the simulated river water. The PPBFs were isolated from freshwater and then cultured in Bio-carrier of Organic Natural Aquatic Mate (BONAM). Based SEM analysis, the periphyton community appears porous and filamentous, with microscopic pores, unique individual cells, and extracellular matrix. Even while each PPBF has a unique structure and function, they all share rich active surface functional groups, particularly carboxylic groups. The epiphyton was found to be more effective for the removal of TMs when tested at 20 mg/L of the TMs as evidenced by the 79.50% elimination of arsenic (As) following 144 h of treatment. The removal performance of epiphyton decreased to just 57.40 and 51.60% at TMs concentration of 40 and 60 mg/L, respectively. Temperature had a significant impact on the biosorption of TMs utilising epiphyton, as evidenced by the removal efficiency of 75.05% at 15 °C, which decreased to 69.50 and 61.00% at 25 °C and 35 °C, respectively. The findings pertaining to the removal of TMs most accurately represented pseudo-first-order kinetics, indicating the bio-absorption of the TMs into the PPBFs. The elimination of almost 92% of TMs under optimal conditions of 90 h of incubation at neutral pH, 25 °C, 1.0 g L⁻¹ of biomass, and 20 mg/L of TMs concentration demonstrated that epiphyton was the most effective biomaterial.