The interrelationship between biological effects and the persistence of pentachlorophenol and HgCl₂ in various soils

Biodegradation and the effects on soil microflora were investigated for pentachlorophenol (PCP) and HgCl₂ in the laboratory for 90 days and 3 different soils. For both biocides, total residues decreased during the experimental time. The time‐course of damage to the soil microflora did not follow the time‐course of dissipation of the residues. The damages caused in soils with low content of organic matter were larger than in soils with high content of organic matter. Application of different initial concentrations of the biocides shows a significant positive correlation between initial concentrations and biological effects. Soil containing bound residues of PCP, when amended with fresh soil, showed only a significant decrease in ATP content at the highest concentration level; soil respiration, heat output and FDA hydrolysis were not significantly affected.

Key words:

• Soil
• pentachlorophenol
• mercury‐II‐chloride
• microflora
• biodegradation