Effect of pH on the removal of metal ions associated with produced water on pulverized oyster shells (OS) as adsorbent

Abstract

This research aims to investigate the effect of variation of medium pH on Metal ion sorption potentials of pulverized Oyster Shells as adsorbent in produced water from selected flow stations in the Niger Delta region of Nigeria. Produced water samples were collected from six (6) different oil drilling installations (CC7T, CC8T, WELL 2 GSS, WELL 8 TEB, AZUZUAMA ST 1, AZUZUAMA ST 2) around the Niger Delta area of Nigeria. Atomic Absorption Spectrometer (AAS) was used to determine selected metals; Nickel (Ni), Cobalt (Co), Copper (Cu), Iron (Fe), Lead (Pb), Calcium (Ca) and Potassium (K) concentrations before and after adjustment of pH of the medium. The results obtained showed that Nickel, Iron and Lead were completely removed from the produced water at a pH of 11.1 while Cobalt, Copper, Calcium and Potassium concentrations were not affected by adjusting the pH either in the acidic or basic ranges. There were small and slight reductions of Nickel, Iron and Lead in the acidic pH of 5.6. The study underscores the need to further compare the above method’s efficiency with other detoxification technologies like Detoxification by chemical reaction (DCR) technology which appears to be more effective, efficient and environmentally friendly.