Produced water treatment using olive leaves

Abstract

Olive leaves powder (OLP) was employed as a low cost adsorbent for the removal of hexane extractable crude oil from simulated produced water. The effect of contact time, adsorbent dosage, pH, salinity as well as temperature on the efficiency of oil removal was investigated. The optimum parameters for oil removal were determined to be pH = 7.0, adsorbent dose = 3.0 g/L, contact time = 80.0 min and salinity of 1,000 ppm in terms of NaCl at 25.0°C. The adsorption of crude oil by OLP was found to follow the Langmuir adsorption isotherm, with adsorption capacity of 143mg/g. The adsorption kinetics best described by pseudo-second-order with rate constant of 1.6 x 10–3 (g/mg.h). Heavy metal content of produced water and the ability of olive leaves to remove these heavy metals were also studies. The fraction of crude oil removed as well as the nature of olive leaves surface were characterized by thermal analysis, gas chromatography-mass spectrometry and infrared spectroscopy. The results render OLP as an excellent adsorbent for the removal of hexane extractable fraction of crude oil from produced water with an efficiency exceeding 80% in 80 min.