| Popis: |
In this research, we perceived that some approaches adopted by environmentalist and researchers to remediate crude oil contaminated soil, by using microorganisms such as Pseudomonas aeruginosa, Aspergilus nigar and Azotobacter have obvious drawback. Thus we set out to adopt synergistic application of earthworms and brewery mash as consortiums for cleaning-up crude oil contaminated soil. The result gave significant reduction of contaminants in the soil. The efficiency of this approach arose due to considerable biological influence of earthworms in the soil by burrowing, feeding on the brewery mash, promoting aeration and facilitating rapid oxidation of the contaminants. The brewery mash was introduced as nutritional additive that would supplement for the depleted nitrogen and phosphorus, to facilitate associated feeding regimes. Wherein the brewery mash serve as carbon source to the earthworms. The results suggest that the co-application of Nsukkadrilus mbae and brewery mash promoted the reduction of both recalcitrant TPH and PAHs crude oil-contaminated soil. It equally showed that by increasing the number of earthworms, will further enhanced loss of contaminants. Considering the relative availability and affordability of earthworms and brewery mash, this approach is unarguably economical. Field application of earthworms and brewery mash for bioremediation would require careful consideration in matching earthworm treatment approach with appropriate earthworm species. Thus, earthworms enhance oil degradation via oxidation processes due to the aeration resulting from burrowing activities, increased microbial availability of hydrocarbons due to bioturbation and facilitate microbial activities. The observed increase in respiration rate by microorganisms indicates that earthworms and brewery mash have positive influence on microbial activities. In general, if given longer time, the synergistic application/activities of earthworm and brewery mash contaminants clean-up would be absolute, beneficial and economic approach to bio-remediate dissolvable and recalcitrant contaminated hydrocarbons in polluted soil. |
