Laboratory Production and Testing of Biocompost from Water Hyacinth (EichhorniaCrassipes) for Bioremediation of Crude OilImpacted Agricultural Soil

Abstract

The water hyacinth (Eichhornia crassipes) is an invasive aquatic weed that poses challenges in water bodies. The goal was to produce a biofertilizer (compost) from water hyacinth using a locally fabricated metal bioreactor, and test the compost on the bioremediation of crude oil-impacted soil. Water hyacinth was hand-picked and loaded into canoes, during the day time, at the New Calabar River, Choba, Rivers State. Freshly harvested plants were sun and air dried at ambient outdoor conditions and then shredded using a standard cutter. The samples were fed into a 250L bioreactor at half capacity loading. The samples were irrigated to 60% v/w with a suspension of a consortium of microbes isolated from cow rumen liquid. The bioreactor, designed with baffles, was operated by mechanical turning to effect tumbling and mixing. The material was composted for sixty days. The resulting compost was ground into coarse powder using a motorized industrial grinding mill. A final grinding with a manual grinder was done to improve the solubility. The water hyacinth compost (WHC) finished product was used to effect bioremediation of crude oil-impacted agricultural soil under laboratory conditions. Results reveal 71% reduction in Total Petroleum Hydrocarbon TPH in the compost-treated set ups; this compares with 12% in the untreated set ups. There was an increase in the microbial load in the WHC-treated set ups where the microbial counts ranged from 3.3±3 ×107 to 7.0±3 ×107 cfu/g. The procedure described here gave a microbial bio-technopreneurial produce that is useful in remediating hydrocarbon-impacted farm lands.