Removal of oil emulsion from aqueous solution by using Ricinus communis leaves as adsorbent

Abstract

Waste engine oil is a highly pollutant material that requires responsible management. Waste engine oil may cause damage to the environment when dumped into the ground or into water streams including sewers. The Ricinus communis leaves are one of the common wastes abundantly available in Iraq. The present study aims to investigate the performance and effects of Ricinus communis leaves as adsorbent for removing dissolved oil in oil–water emulsion, and the study investigated the effect of different parameters like particle size, pH, initial oil concentration, contact time, adsorbent/adsorbate (g/g) ratio. The maximum removal efficiency of Ricinus communis leaves was 98% at adsorbent particle size (150–300) micron, acidified solution (pH < 2), 90 min for adsorbent concentration of 400 mg/L. Several tests like BET, FTIR and SEM had been conducted for best interpretation of adsorption mechanism in this study. FTIR test displayed good ability of the adsorbent in adsorption of aliphatic and aromatic hydrocarbons. When isotherm study was applied to the results, best fitted data were close to Freundlich isotherm, and the results also had been fitted with kinetic adsorption equations; in the present work, pseudo-second-order equation was the best equation of oil engine uptake.