Comparative Study on Mechanic Workshop Polluted Soil Treated With Lime (Citrus Aurantifolia) Juice, Powder and Inorganic Lime Fertilizer

Abstract

An assessment of mechanic workshop polluted soil treated with 16.6% lime juice (MSAL), mechanic workshop polluted soil treated with lime powder (MSLP) and mechanic workshop polluted soil treated with inorganic lime fertilizer (MSLF) was conducted for a period of 56 days. The study revealed higher microbial counts in the treated soils compared to mechanic oil free soil (MFS). The total viable bacterial counts observed ranged from 1.6×10⁴ cfu/g to 6.8×10⁴ cfu/g for MSF, 2.2×10⁴ cfu/g – 26.2×10⁴ cfu/g for MSAL, 1.2×10⁴ cfu/g -17.2×10⁴ cfu/g for MSLP and 6.8× 10⁴ cfu/g – 16.0 × 10⁴ cfu/g for MSLF while fungi counts ranged from 2.5×10⁴ cfu/g to 6.4×10⁴ cfu/g for MFS, 4.0×10⁴ cfu/g – 16.4×10⁴ cfu/g for MSAL, 2.6×10⁴ cfu/g -3.8×10⁴ cfu/g for MSLP and 2.1× 10⁴ cfu/g – 4.0 × 10⁴ cfu/g for MSLF. Organisms isolated  in the course of the study includes Pseudomonas sp,  Staphylococcus sp, Bacillus sp, Micrococcus sp, Escherichia coli,  Proteus sp, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Mucor sp,  Saccharomyces sp, and Rhizopus sp. The physicochemical results showed that MSAL had higher moisture content, organic matter content, organic carbon, and nitrate than MSF, MSLP and MSLF. There were significant differences in pH, organic matter content, organic carbon, nitrate and phosphorus at 0.05 probability level, but there was no significant different in the moisture content of the soil undergoing treatment. This is an indication that Lime juice has a greater potential in bioremediation of mechanic workshop polluted soil compared to lime powder and inorganic lime fertilizer.