Organic by-products for sustainable soil remediation -the effect of 3 different amendments on the degradation of diesel fuel in a tropical ultisol

Abstract

In many tropical developing countries, economic incentives are small for soil remediation to take place. Such locations demand special strategies that are energy-efficient, locally adapted and economic. In situ technologies are appealing where energy and material costs are more limiting than the time factor. One potentially sustainable and economic way to enhance the self-organizing capacity of soil ecosystems is by applications of locally available organic byproducts to stimulate the polluted ecosystem´s inherent capacity to heal by utilising the embodied energy of the organic pollutant itself, as an energy source for the necessary biochemical transformations. Tropical climate is favourable for biodegradation but many tropical soils are rich in clay which can inhibit the bioavailability of the pollutant and reduce biodegradation kinetics. A pilot scale experiment was performed in order to assess the capability of three amendments based on by-products; whey, pyroligneous acid and compost tea, to enhance degradation of diesel in ultisol. Biweekly applications of 6 mL whey kg -1 soil significantly increased the degradation rate but no positive effect on degradation was found of any of the other amendments.