ABSTRACT
The pollution of soil by crude oil or other hydrocarbon is a major problem faced by many countries and territories around it is caused when pipelines are vandalized or when there is improper disposal of waste from processed oil or leaks and damages in pipelines. These polluted soils go on to have a huge adverse effect on the population of people living in these places, it affects the water which they drink and use for other functions. This problem can be remedied by the bioremediation of the soil which is the use of microorganisms to biological agents to act on the soil, thereby remediating it.
Bioremediation has been proven to be the best method of remedying polluted soil because physical methods may prove extraneous and time consuming while chemical methods could leave harmful by-products and side reactions. In this study, pig manure was used to remediate crude oil polluted soil for a period of 8 weeks.
3.7kg of pristine dry top soil was collected and mixed with 600ml crude oil and then 1.9kg of pig manure was added to it along with 20g of nutrient agar. This was kept for 8 weeks and periodically tested week by week to obtain results.
These results showed that there was a gradual steady reduction in the total hydrocarbon content (THC) from an initial value of 7.06mg/kg to 2.45mg/kg at the end of the 8-week period, reduction in other properties like total nitrogen (TN) from 5.12g/kg to 2.32g/kg because it was utilized by the microorganisms in biodegradation. The total phosphorus (TP) also. An increase in pH from 3.6 to 6.10 indicating a former acidic nature to a rather more neutral nature of soil, and total heterotrophic bacteria (THB) was recorded an increase from 6.07*105 to 3.02*105 The results of this study indicated that pig manure is a good, easy and inexpensive way to enhance the rate of biodegradation of crude oil polluted soil.
