Removal of organic compounds from olive mill wastewater using an eco-friendly adsorbent: Characterization, kinetics, isotherms, thermodynamics, and interaction analysis

The use of clinker as a filtering medium is a new method for treating the waste water from olive mills (OMWW), which is a highly toxic effluent for the environment due to its high organic load and its huge concentration of phenolic compounds as confirmed by HPLC analysis. Scanning electron microscopy (SEM), Energy-dispersed X-rays (EDX), Brunauer-Emmet-Teller (BET) and Fourier transformed infrared spectroscopy (FTIR) were used to characterize the prepared clinker. Additionally, adsorption tests were conducted to evaluate the performance of the clinker. The adsorption study was carried out under different conditions such as contact time, pH value, adsorbate concentration and temperature. The adsorption mechanisms are described using the Langmuir, Freundlich, and Temkin isotherms, the pseudo-first-order and pseudo-second-order models represent the kinetics while the thermodynamic study of adsorption examines how thermodynamic properties influence the adsorption process. The results indicate that the pseudo-second-order model and the Freundlich isotherm are most suitable for the adsorption of OMWW. The results showed that the clinker can adsorb 1001.61 mg/g at an initial concentration of 5000 mg/L.