国際廃棄物資源ジャーナル

概要

Soil and Water Microbiological Characteristics of Olo Flowstation and Rumuekpe Metering Station, Rivers State, Nigeria

Nwankwoala HO and Youdeowei PO

This study evaluates the soil and microbiological properties of Olo Flowstation and Rumuekpe Metering Station. Standard sampling and analytical methods were adopted. Results of the soil microbiological composite samples from the random samples showed that the percent Hydrocarbon Utilizing Bacteria (HUB) was 40.0% and 27.27% for the top and subsoil, respectively. Though these values were high, they were below expected values in view of the high level of petroleum hydrocarbon spilled on the soils collected. The moderately high amount of hydrocarbon degraders in these soils compared to the control indicated that these soils might have been in contact with petroleum products which might have polluted the soils. The poor drainage resulting from stagnant water might have leached the petroleum products down the soil along transect, resulting into higher HUB% in the subsoil than the top soil. Other sampling stations had better top soil drainage hence lower % HUB down the profile. All the water samples, both surface and groundwater showed significant range of bacteria. The colonies were within 30 to 300. The growth for bacteria ranges from 1.5 × 105 cfu/ml at Elele-Alimini (up-stream) to 3.0 × 105 cfu/ml at the waste pit, Sombreiro River and flare pit. The heterotrophic organisms isolated were Bacillins sp., Chromobacterium sp., Micrococcus sp, Enterobacter sp., and Psendomonas sp. The presence of the bacteria in the water bodies (effluent) indicated a regrowth and general bacterial composition of the water. The petroleum degraders isolated in the surface waters where Chromobacterium sp., Micrococcus sp., Psendomonas sp. and Bacillus sp. The microorganisms population range from 1.0 × 102 at Elele-Alimini down-stream to 6.0 × 102 at discharge point-Waste pit and the borrow pit at Rumuekpe. The preponderance of petroleum utilizing bacteria in these water samples indicated the presence of hydrocarbons. The fungal count was generally low and was found in Elele-Alimini up-stream and borrow pit near the metering station at Rumuekpe. The mean count of E. coli per 100 ml of water was 180+ meaning that all the water samples both surface and groundwater were polluted. The presence of E. coli showed faecal pollution of the water and there could be possible presence of pathogenic organisms in the water. This study therefore will be a useful guide to farmers in the areas around the flow stations. There is also need for treatment of surface and groundwater in the area. It is recommended that regular monitoring of the geo-environmental media be carried out.