Author(s): Kirushantini Balakrishnan, Nor Azazi Zakaria, Keng Yuen Foo
Linked Author(s): Kirushantini Balakrishnan
Keywords: Adsorption, carbon aerogel, metformin, pectin, pharmaceutical pollutant
Abstract: The orally administered drug metformin for diabetes type II has spiked in huge production according to the estimation by World Health Organization (WHO), with the reported patients of more than 350 million annually. The prevalence of metformin is frequently detected in the aquatic environment, specifically at the surface level of water supplies, groundwater and stormwater discharge. If poorly managed, the presence of metformin may become a source of hydro-geological contaminant to the natural environment, with a multiple, acute and synergistic toxicity. Metformin is a recalcitrant, accumulative and persistent toxic chemical, with high mobility, solubility and low degradability. In view of the above matter, a broad range of treatment technology has been abounded. In particular, carbon aerogels, a new generation of eco-friendly carbon adsorbents, has received wide concern due to the favourable capability for the treatment of a variety of pharmaceutical contaminants. In this work, the preparation of low cost carbon aerogel (CA) from natural pectin was attempted via ambient pressure drying. The physical, chemical and physiochemical properties of CA were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), nitrogen adsorption-desorption curve and zeta potential measurements. The adsorptive behavior for the treatment of metformin was investigated by varying the initial concentration, solution pH and operating temperatures. Equilibrium data were simulated using the nonlinear Langmuir, Freundlich and Tempkin isotherm models, while the adsorption kinetics were fitted to the pseudo-first-order and pseudo-second-order kinetic equations. SEM images projected a well-developed porous structure, with the specific surface area of 584. 19 m2/g. The removal of metformin was dependent on the variation of pH, in accordance to the Langmuir isotherm model, denoted a maximum adsorption capacity of 224. 81 mg/g. The research findings verified the potential of natural apple pectin derived carbon aerogel as an effective solution for the successive treatment of metformin contaminated water
Year: 2017