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

Abstract

Contaminated soil from industrial or agricultural activities poses a health threat to animals and humans and can also have a detrimental effect on economic systems by making land unsuitable for agriculture and other economic purposes. This problem is of particular concern in tropical developing countries where agriculture is the economic base. Traditional methods for soil remediation are often expensive and energy consuming. In-situ bioremediation has been proposed as a cheaper alternative to conventional methods in areas where remediation would otherwise not be implemented. Despite encouraging results in the laboratory, the practice of in-situ bioremediation is limited, partially due to its inefficiency at low temperatures. The objective of this study is to provide an inventory of some waste products that potentially can be used as amendments for in-situ bioremediation in developing countries in tropical climate. Emphasis has been given to map efficient methods that are appropriate to economically marginalised people in such countries. Waste from livestock operations, crop residues and processing waste constitute the major waste flows in many developing countries. A number of organic by-products can potentially be used to stimulate microbial activity for bioremediation purposes. Three amendments; whey, pyroligneous acid and compost teas were selected to be studied in detail due to their liquid nature and documented capacity to stimulate microorganisms with capacity to degrade pollutants. Experiments are needed to determine their potential for in-situ bioremediation in developing countries in tropical climate.