The bio-adsorption competence of tailor made lemon grass adsorbents on oils: An in-vitro approach

The oil contamination in aquatic system is considered as most serious environmental issues and identifying a suitable ecofriendly solution for this oil pollution management is critical. Hence, this research was designed to evaluate the oils (petrol, diesel, engine oil, and crude oil) adsorptive features through raw lemon grass adsorbent, physically/chemically treated adsorbents. Initially, such raw and treated adsorbents were characterized by Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and Energy-Dispersive X-ray Spectroscopy (EDS) analysis. These characterization techniques revealed that the lemon grass adsorbent had considerable level of pollutant adsorption potentials owing to porous morphological structure, active functional groups and pollutants interaction with chemical elements. The physically treated adsorbent exhibited better adsorption characteristics than others. Accordingly, the petrol adsorption potential of raw adsorbent, physically treated and chemically treated ones was discovered as their weight incremented up to 2.0, 3.0, and 1.5 times their initial weight, respectively. Similarly, the weight of raw form, physically and chemically treated ones on diesel had increased significantly, up to 2.5 times, 4.0 times, and 2.0 times, respectively. It was evaluated that the weight of these tested adsorbents on engine oil incremented by 3.5, 5.0, and 3.0 times their initial weight, while on crude oil these incremented by 4.0, 6.0, and 4.0 times their initial weight respectively. When the media are compared, it's indeed evident about absorption which is preferred as follows: Crude oil, engine oil, diesel, and petrol. The physically treated lemon grass adsorbent showed maximum adsorption and retention potential than others. The kinetic study reveals that the pseudo second order kinetics is the best fit for the adsorption of oil with R² value of 0.99.