Green Ca-Loaded MgO Nanoparticles as an Efficient Adsorbent for Organic Hazardous Dyes

Textile industry wastewater is a principal source of environmental contamination, posing serious health and environmental risks; consequently, appropriate treatments are necessary before ultimate discharge to ensure environmental and public health safety. In this study, 10% Ca-doped MgO (Ca0.10Mg0.90O) has been prepared via a green and ecologically benign approach using aqueous solution of gum arabic (GA) and then used to eliminate Congo red (CR) from aqueous solution. The XRD analysis reveals a size reduction of MgO nanoparticles from 11 to 6 nm after doping with a surface area reaching 50.1 m2·g-1 for the synthesized heterostructure. An excellent adsorption efficiency of 97% has been achieved under the following optimal operational conditions, i.e., adsorbent dosage of Ca0.10Mg0.90O (0.400 g/L), contact time of 120 min, and solution pH of 7.00. As indicated by pH, isotherm, and FTIR examinations, the CR sorption process is related to chemisorption and hydrogen bonding. The findings indicate that the synthesized nanomaterial is a suitable candidate for dyes containing effluent treatment due to its facile green synthetic approach using a natural product GA, low-cost, mesoporous nature, and high uptake capacity under neutral solution pH.