Small Scale In-Situ Bioremediation of Diesel Contaminated Soil – Screeing Life Cycle Assessment of Environmental Performance

Abstract

Spillage of diesel oil and other petroleum products is a commonly creating need for site remediation of contaminated soils. In Sweden the most common remediation action is excavation of the contaminated soil and off site biological treatment by composting. However, a number of small sites spread out in rural areas end up low on priority lists, and will not be attended to within foreseeable future if ever. For such areas a low cost, easy to apply remediation techniques would be of interest. Enhanced bioremediation of diesel contaminants in soil by whey addition has been demonstrated in lab scale. Whey is a by-product from cheese production. A first pilot remediation trial on an actual site in Gäddede, County of Jämtland, was started the summer of 2010. Using this site as a case study a screening life cycle assessment model has been set up. The goal of the study was to investigate the environmental performance of the whey method, to benchmark the whey method toward the excavation and composting practice and to identify environmental hot spots in the whey treatment life cycle. The study aims at establishing if further work should be put into developing the method, or if the environmental performance is such that the whey method should be abandoned. It should be noted that even with a slightly worse environmental performance compared to other remediation alternatives whey treatment could still be of interest, since the small scale sites in rural areas we talk about here otherwise most often would not be attended to. Results from the screening life cycle assessment indicate a rather good environmental performance of the whey method, partly depending on impact category considered. For the whey method, impacts from farming activities in the milk production chain allocated to the whey give significant contributions. Transportation gives important impacts from both the whey method and the excavation and off site composting, thus logistics should always be considered and optimized. The whey onsite treatment could be an interesting alternative for bioremediation especially at sites that would not otherwise be treated, due to small size or remote location.

Enhanced Natural Biodegradation of Diesel Fuel Contaminants in Soil by Addition of Whey and Nutrients

“…Many methods have been tested and today the most common practices include the excavation of large amounts of soil and the transport of the contaminated soil to specialized treatment plants which are sometimes located at great distance from the contaminated site. Results from a screening life cycle assessment indicates that road transport of contaminated soil has a significant environmental impact compared to in-situ treatment of the contaminated site [1]. Methods for both in-situ and ex-situ treatment include addition of food waste, addition of surfactants, aeration, biodegradation in reactors etc.…”

Turning Waste Into a Resource for Remediation of Contaminated Soil in Tropical Developing Countries

“…the utilisation of microorganisms and plants with the ability to degrade or immobilize toxic compounds has been proposed as a cheaper alternative to conventional methods [4][5][6]. Despite encouraging results in the laboratory [7][8][9][10], the practice of in-situ bioremediation is limited [11,12], partially due to its inefficiency at low soil temperatures [8]. Soil temperatures in tropical countries however present conditions that are favourable for in-situ soil bioremediation.…”