Modeling Environmental Impact Factor of Harmful Chemical Compounds in Polluted Water Discharge in Offshore Installations

The development of a novel model to study the fate and environmental impact factor (EIF) of harmful chemical compounds in polluted water discharges from an offshore installation in Nigeria's marine environment was carried out in this study. The developed numerical fate model incorporates the environmental impact factor, , derived stochastically on a specific fuzzy logic-based framework, and the boundary value problem of the resulting fate and EIF model was solved via finite element method in MATLAB environment and the Dose-related Risk and Effects Assessment Model (DREAM) software using prevailing field and meteorological conditions of the marine environment. The fate concentrations of oil dispersants, harmful heavy metals (such as copper and mercury), and aromatic compounds (such as naphthalene, benzene-toluene-ethylbenzene-xylene (BTEX)) simulated at polluted water discharge rates of 3,000, 5,000, 25,000 and 75,000 barrels/day (bpd)) and average temperature of 27oC were used to compute EIFs of harmful chemical compounds in the marine environment. The results showed the produced water (PW) discharged volume and the corresponding EIF. For produced water discharge rates of 3,000, 5,000, 25,000 and 75,000 bpd, the simulated EIFs are 0, 5.6135, 5.3072 and 3.7150respectively, which is indicative of environmental risk far greater than the commonly accepted 5% risk margin in the water column in the cases of 5,000, 25,000 and 75,000 bpd. Higher risk impact derived from higher discharge rates may be effectively handled by water dilution and transport.