Remediation trials of crude oil contaminated soil using different sawdust and detergent combination levels

Abstract

A 3 month remediation trial of the use of detergent and sawdust in different combination forms in the restoration of a crude oil contaminated tropical soil was investigated. 8 remediation treatments labeled A – H in addition to the control (I) were used in 10 kg soil artificially polluted with 300 ml crude oil each. Remediation treatments were: A (20 g detergent), B (40 g detergent), C (100 g sawdust), D (200 g sawdust), E (20 g detergent + 100 g sawdust), F (20 g detergent + 200 g sawdust), G (40 g detergent + 100 g sawdust), H (40 g detergent + 200 g sawdust) and I (polluted soil without an amendment) arranged in a completely randomized design. Soil chemical parameters such as total hydrocarbon content, total organic carbon, Total organic matter, nitrogen, nitrate and pH were evaluated. The resulted indicated that the amendments (either in single or combined form) reduced soil electrical conductivity and Total Hydrocarbon Content (THC); and increased soil pH, Nitrate, Nitrogen, Total Organic Carbon (TOC) and Total Organic Matter (TOM). There was also significant increase in the soil microbial counts in the amended soil as compared to the control. Therefore, detergent and sawdust in single or combinations can be used to restore crude oil polluted soil with the ability to reduce the toxic effect with treatment A (20 g detergent) and C (100 g sawdust) and D (200 g sawdust) performing best. Though caution should be taken in their application (especially detergent), as not to cause any adverse effect.

Keywords: remediation, detergent, sawdust, pollution, crude oil, soil