Comparative Carbon Synthesis of Peat using ZnCl2 and H3PO4 for Heavy Metal Adsorption in Oilfield Produced Water

Oilfield Produced Water is one of the amplest wastes resulting from oil and gas operations and it’s of great industrial concern due to its quantity, concentration, and cost of treatment; thus, it needs cheaper and more available options. Peat being an option is a renewable brown deposit resembling soil, formed as a result of an accumulation of organic matter, also known to have a rich carbon content. This research work aims to comparatively synthesize peat soil with ZnCl2 and H3PO4, carbonize, characterize, and determine the efficiency of heavy metal adsorption in Oilfield Produced Water. The peat samples were collected from Warri City commonly referred to as Oil City in southern Nigeria and were impregnated with ZnCl2 (PAC-ZC); H3PO4 (PAC-HP); ZnCl2 and H3PO4 at a ratio of 1:1 (PAC-ZC+HP) and with De-ionized water as control (PAC-D). After activation, peat was carbonized at 400oC for 1 hour. Fourier-Transform Infrared Spectroscopy analysis showed all five samples have a strong silicate ion peak between 998.9 - 1028.7cm-1, the presence of Vincy C-H group at 909.5cm-1, broad shaped polar O-H bond between 369.5 – 3623.0cm-1 and an adsorption peak between 2929.7 – 2012.8cm-1 which disappeared after activation and carbonization. Scanning Electron Microscopy micrograph shows a surface enhancement after activation and carbonization. The heavy metals (Pb, Cu, Ni, Zn & Fe) level in the Oilfield Produced Water was analyzed before and after treatment with Peat Activated Carbon using Atomic Absorption Spectrometry. Four dosages (1,2,3, and 4g) of each Peat Activated Carbon were used to treat 100ml of Oilfield Produced Water. PAC-ZC and PAC-ZC+HP showed 100% efficiency in the removal of turbidity, Pb, Cu, Ni, and Fe. However, the overall efficiency trend of the adsorption capacity of the Peat Activated Carbon was PAC-ZC > PAC-ZC+HP > PAC-HP > PAC-D. With the experimental result, PAC-ZC and PAC-ZC+HP can be used as treatment options for Oilfield Produced Water.