Immutable heavy metal pollution before and after change in industrial waste treatment procedure

This study compared state of pollution around an intermediate treatment plant of industrial wastes before and after the change of its treatment procedure. Bulk atmospheric deposition, surface soil, suspended particulate matter and groundwater were collected after the plant changed main operation to waste crushing and volume reduction. Their heavy metals content were comparatively investigated with the previous results obtained when it was burning wastes. The bulk heavy metals deposition showed a clear distance-related attenuation both in burning and crushing periods, indicating that the plant was the main emissions source in either case. High concentrations of heavy metals in suspended particles, soil, and groundwater during the crushing period indicated their diffusion to water environment over time. The bulk atmospheric heavy metals deposition decreased significantly, 0.20~ 0.49 times for Cu, Zn, Cd and Pb and 0.69~0.94 times for Cr, during the crushing period than burning period. However, change of their enrichment factors was not significant. It may indicate that the pollution state did not change qualitatively in a bulk deposition basis and quantitatively in a depositing particle basis. The results showed that heavy metals deposition is dominated by suspended and precipitated particulate matters that adsorb and transport the metals.