Remediation of cationic and anionic dyes from water by histidine modified mesoporous silica

The organic dye is one of the most problematic water pollutants in the vicinity of leather and textile industries. Adsorption method via functional materials can be considered as an effective method for dye removal from wastewater. In present work, the synthesis of mesoporous silica nanoparticles (MSNs) functionalised with histidine (MSN-His) has been reported for simultaneous removal of methylene blue (MB) and phenol red (PR) from an aqueous solution. The properties of nanoparticles were characterised in terms of size, surface area and surface modification using a scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR). The influence of various factors including the contact time, the initial concentration of the adsorbate and pH of the medium on the MB and PR adsorption efficiencies were investigated. The maximum adsorption capacity was calculated to be ca. 65 mg/g for MB in basic media, and ca. 55 mg/g for PR in acidic media. The adsorption isotherm is fitted with Freundlich for all solutions. The maximum removal efficiency was ca. 70% for MB in basic media and PR in acidic media after second cycle.