Methods for investigation of old glass waste dumpsites

An old glass dumpsite in southern Sweden was mapped and investigated to locate glass abundance zones (“hotspots”) and understand physicochemical parametres of the waste. Global Positioning System (GPS) was used for mapping the site while a geophysical method of Electrical Resistivity was used for detecting glass hotspots in the dump. Test pits were excavated and samples taken, after which hand sorting, sieving and X-Ray Fluorescence (XRF) scanning of the waste were used for physicochemical properties. Geophysical mapping was found to be a feasible nondestructive tool in locating glass hotspots. In terms of composition, glass was found to be the most abundant fraction at 90% average from all 4 sampling points. From particle size distribution, particles > 11.3 mm were more abundant (75% average) than particles < 11.3 mm. XRF scanning yielded As, Cd and Pb concentrations of 3,700 mg/kg, 500 mg/kg and 5,300 mg/kg, respectively. In conclusion, it is possible to locate glass hotspots and excavate them carefully in readiness for metal extraction while avoiding the need for complicated sorting post-excavation.