Low-cost Liagora farinosa/zeolite nanoporous composite for Congo red removal from wastewater

Abstract

A research plans comprising comprehensive analytical, laboratory, and field trials were successfully applied for precise exploration of a new facility to help in removing Congo red (CR) dye from industrial effluent effectively. Zeolite/algae (ZLF) nanocomposite was prepared by applying wet impreg-nation technique in order to incorporate one of the known Egyptian marine algae Liagora farinosa (LF) within the lattice of natural zeolite. Each of alga (LF), zeolite (Z) and ZLF nanocomposite were examined on the basis of structures, morphologies, and adsorption capacities using batch experiments to clarify the effect of different experimental factors on the ability of all adsorbents to capture CR dye from aqueous solutions. The preliminary results indicate superior adsorption capacity for the newly synthesized ZLF nanocomposite over Z and LF adsorbents, especially at lower CR dye con-centrations. At pH 7 and 25°C, the maximum adsorption capacities were found to be 19.01, 11.23, and 8.1 mg/g for ZLF, LF, and Z, in the same order, which confirms results of the preliminary results on adsorption properties for the composite. Additionally, the Z, LF, and ZLF removal efficiency obtained from batch experiments were 65%, 84.21%, and 97.37% respectively. The ZLF nanocomposite newly synthesized in this study revealed a promising low-cost alternative adsorbent for holding and uptak-ing anionic dyes from industrial wastewater stream especially at low CR dye concentrations. The iso-therms of dye adsorption on Z, LF, and ZLF were in well agreement with the Langmuir isotherm as well as pseudo-second-order kinetic model. In order to assess the sorption mechanism, Weber’s intraparticle diffusion module was applied. The thermodynamic results showed that the adsorp-tion of the CR dye onto Z, LF, and ZLF at 25°C is spontaneous, physical adsorption and exothermic process. Finally, a real field sample was tested and the results revealed that the newly synthesized nanoadsorbent extracted dyes from industrial wastewater with a 90.97% efficiency, reaffirming the cornerstone of modern eco-friendly materials that aid in the reuse of industrial wastewater.