STUDIES ON THE MICROBIOLOGY AND BIOGEOCHEMISTRY OF SOME INDUSTRIAL WASTES AND A PRELIMINARY EVALUATION OF THE USE OF BIOCHAR IN SPOIL REMEDIATION

The aim of the work described in this Thesis was to study the biogeochemistry of a variety of industrial spoils, ranging from a highly alkaline steel slag spoil to a slightly acidic colliery spoil and acidic metal mining wastes, with the ultimate aim of providing information which might be used in the remediation of these spoils by applying a plant cover. A variety of important processes, which are components of the major biogeochemical cycles (i.e. urea hydrolysis, nitrification, s-oxidation, and P-solubilization) were studied in these spoils. The activities of a range of soil enzymes (e.g.arylsuphatase and arylphosphatase) were studied in the spoils in relation to their use as possible indicators of microbial activity and thereby spoil fertility. In addition, phosphate solubilizing microorganisms were isolated in relation to the role they play in influencing the availability of phosphate to plants which, with nitrogen is likely to be a major limiting factor for spoil bioremediation. A preliminary study was also made of the potential for using Biochar in the remediation of these spoils. The results are discussed in relation to the bioremediation of these industrial spoils. The desirability of achieving such spoil-remediation relates mainly to aesthetic considerations, i.e. the presence of spoil tips ruins the local environment a factor which impacts on tourism and the introduction of “clean industries” to former mining areas.