Simultaneous adsorption behaviour of heavy metals from Oil Mill Wastewater onto natural clay

Abstract

The present work reports the synergistic and inhibitory adsorption effects involved in the multicomponent adsorption of heavy metal ions (Fe (II), Pb (II)), and major elements from oil mill liquid waste (OMW) using natural bentonite as adsorbent cames from Nador (North-East Morocco). Morocco is one of the most olive oil producing Mediterranean countries. This industry, which is so beneficial to the national economy, leaves two toxic and non-biodegradable residues (liquid/solid). OMW or margin is a current liquid pollutant that has been listed by the United States Environmental Protection Agency (EPA). The classical methods used for phenol removal are expensive or limited to large-scale applications such as biological and thermal decomposition methods. The margins used in the studies were collected from a semimodern oil mill (Nador-Morocco). The results of the physicochemical analyses showed that the effluents of the oil mills showed that they are highly polluted, in particular the suspended solids, COD, and iron contents of around 154.82 (mg/l) and copper 31.72 (mg/l). Samples of OMW mixed with raw bentonites at different percentages vary between 10 % and 80 %. Different interactions between bentonite and metal ions dealing with the decrease of the concentrations. This study proves that this bentonite is an effective adsorbent for the elimination of heavy metals from OMW.