Development of a Novel Path for the Bioremediation of Crude Oil-Impacted Non- Turbulent Water Bodies under Isothermal Conditions

Abstract

Crude oil spill has become a common phenomenon during oil production,
transportation, and refining operations. It can occur in both land and water.
While bioremediation and the use of cow dung for oil spill treatment have been
established as an effective and environmentally friendly approach in the
management of crude oil spill in land, little has been reported as it concerns water
and most importantly, non-turbulent water bodies. The possibility of this
application is of interest because non-turbulent water bodies have been reported
to support the transport of petroleum hydrocarbon components down the water
column, making the containment and treatment of polluted top surface
insufficient. This paper reports on effort to treat an entire non-turbulent water
body polluted with crude oil and with petroleum hydrocarbons diffusing through
different depth of the water column. This was achieved by designing balls of cow
dung with densities corresponding to that of the different depth strata of the water
column, and then introduced into the polluted water. The balls then dissociate
after a while, and filling the entire water volume with the cow dung particles, thus
providing the necessary nutrients for microbial growth and activities across the
entire water body. Samples of the water after treatment were then collected within
a four (4) weeks post-treatment period and analysed using a GC-FID. At the end
of the first week of treatment, the result showed a reduction of aliphatic
hydrocarbons from 171.827mg/l, 98.641mg/l, 31.075mg/l and 18.675mg/l to
95.991mg/l, 33.914mg/l, 4.128mg/l, and 0.42mg/l and 1.12mg/l, 0.075mg/l, 0mg/l,
and 0mg/l in the fourth week and at depths of 0.25m, 0.5m, 0.75m and 1.0m
respectively. In the same vein, the aromatic hydrocarbons at the same depths, and
after the first week of pre-treatment were 23.816mg/l, 12.942mg/l, 3.336mg/l and
0.962mg/l. At the end of the fourth week of post-treatment, negligible amount in
all depths were recorded. These results show that the approach can be adopted in
the treatment of oil spills in non-turbulent mangrove water bodies.