A novel and eco-friendly Algae amino-modified nanoparticles with significant environmental effect for the removal of As(III) and As(V) from water

Abstract

Biomass created by algae-based water purification has several potential applications outside the conventional energy, agriculture, and chemical industries. Herein, we use a specific type of algae, Enteromorpha intestinalis Ei, to remove significant metal ions. The Ei particles was converted into nanoparticles mechanically and their surface was chemically modified based on amino silane linker. The effect of utilizing dried Enteromorpha intestinalis nanoparticles, EiNPs, and silica-coated Enteromorpha intestinalis nanoparticles, Si-EiNPs, was examined for removing arsenic ions from an aqueous solution. Fourier transform infrared spectroscopy (FTIR) studied the chemical structure and shape of dry and silica-coated Enteromorpha intestinalis nanoparticles. Transmission electron microscope (TEM), Brunauer Emmett Teller (BET), and scanning electron microscopy (SEM). Batch experiments used the adsorbent dose, pH, temperature, contact time, and initial content of arsenic ion. The optimum conditions were exhibited by As3+ and As5+ concentrations of 10 ppm, contact time of 40 h, biosorbent dosage of 200 mg, Temperature 25±1°C, pH 6 for As3+ and pH 3 for As5+ and agitation rate 150 rpm. Thermodynamic experiments confirmed that the process is both spontaneous and exothermic. Kinetic models comprising pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were implemented to examine the adsorption process of arsenic ions on the surface of the studied nanoparticles. Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models were examined to define equilibrium isotherms. However, the data were deemed to be better explained by the Freundlich isotherm model. The results indicate that the examined adsorbents, particularly EiNPs and Si-EiNPs, possess a strong capacity to adsorb and desorb arsenic ions, effectively purifying a contaminated effluent.