THERMAL-CONVERSION OF GASWORKS CONTAMINATED SOIL INTO CARBONACEOUS ADSORBENTS

Contaminated soil from a gaswork site has been successfully converted into a carbonaceous adsorbent utilising ZnCl2 as an activating agent. The organic contamination, consisting of coal tars, phenols and associ ated compounds, was converted into a carbonaceous material. Extensive reduction (95%) in the cyanide content of the soil after treatment was observed and entrapment of metallic contamination within the carbonac eous matrix has been observed through XRF analysis. Surface area and p orosity analysis by gas adsorption indicates surface areas ranging fro m 110 to 570 m2/g, and development of microporosity within the carbons . The complex contamination within the soils has influenced the develo pment of adsorption characteristics within the samples, and sulphur, i n particular, appears to play a major part in the development of this.