Journal of Petroleum & Environmental Biotechnology

Abstract

Adsorptive Removal of Heavy Metals from Oil Well Produced Water Using Citrus sinensis Peel

Stephen G Udeagbara*, Isehunwa S.O, Okereke N. U, Nwanwe O, Oguama I and Kerunwa A

Produced Water (PW) from hydrocarbon reservoirs contains toxic metals very often and other impurities that are harmful to the ecosystem This research was aimed to checkmate the impact of citrus sinensis (orange peel mixed with the fiber) as a bio-adsorbent for the treatment of PW from Niger Delta oil field.

An adsorption column of 2.0 m (0.4 m internal diameter) with four treatment compartments was fabricated using standard procedures. Citrus sinensis peel was washed thoroughly with distilled water, sun-dried (4 days during harmattan period) and oven-dried at 105 ± 5°C for 3 hours. It was ground into powder, sieved (150 and 300 microns) and then washed with 0.4 mol/L HNO₃, filtered and rinsed with distilled water to remove any impurity that might interfere with the result. Sample of PW was obtained from field R in the Niger Delta and analysed for heavy metals using an Atomic Absorption Spectrophotometer (AAS). Sample was treated in adsorption column over 3 hours using 150 micron size of adsorbent. Treatment was repeated with 300 micron size. Adsorptions of heavy metals were evaluated after treatment using Langmuir and Freundlich models. Data were analysed using regression and ANOVA at α 0.05.

Concentrations of barium, copper, lead (96.2), nickel (47.2) and cadmium (78.6) in PW from field R reduced by 42.1, 96.1, 96.2, 47.2 and 78.6 percent, respectively after 4 hours of treatment with 150 micron size and for 300 micron size, the concentrations of the same metals reduced by 3.0, 88.8, 57.1, 11.8 and 18.4 percent respectively. The concentrations of other metals were equally reduced to an acceptable limit. The orange peel (Citrus sinensis peel) bio-adsorbent was effective in the adsorption of the metals present in the PW. Langmuir model best described the adsorption of lead with isotherm R2 of 0.97, while Freundlich isotherm described the adsorption of nickel and iron, with isotherms R2 of 0.84 and 0.93 respectively.

Produced water from Niger Delta oil field was effectively treated of contaminants using Citrus sinensis peel with 150 micron size gave the best result.

Published Date: 2024-08-12; Received Date: 2022-03-07