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Direct inoculation of bacteria capable of degrading pentachlorophenol (PCP) into PCP-contaminated soil was investigated as a prophylactic measure to reduce the hazards of runoffs when spills occur or when wooden poles freshly treated with PCP-containing preservatives are located near streams and lakes. In laboratory tests at 30°C, the direct addition of 10 6 PCP-utilizing Arthrobacter cells per g of dry soil reduced the half-life of the pesticide from 2 weeks to <1 day. Soil inoculation also was shown to be an effective way to increase the PCP disappearance rate in a test conducted in an outdoor shed.

The potential of using carbonized slash pine bark as a substitute for activated carbon was examined in this study. The bark was carbonized by slow heating in nitrogen for 6É5 h to 672¡C. The surface area, average micro-BET-N 2 pore and mesopore diameter, and micropore volume were 332 m2 g~1 21É7 Ó, and 0É125 cm3 g~1, respectively. The adsorption capacities for phenol and pentachlorophenol (PCP) at pH 2 and pH 8 were evaluated. The Langmuir equation provided a slightly better Ðt than the Freundlich equation to two sets of phenol data. The calculated Freundlich constants, K \ 0É41È0É58 mmol/g/ (mmol dm~3)1@n and 1/n \ 0É30È0É41, were lower and higher, respectively, than literature values for activated carbons. The adsorption capacity of the carbonized bark was much lower for PCP than for phenol. The protonated and anionic PCP isotherms were Type II or III, respectively, in the Brunauer classiÐcation. The BET equation provided the best Ðt to protonated PCP isotherm data. The anionic PCP data were Ðtted to both the BET model and an equation used in the literature to represent phosphate adsorption on activated carbons. Nonlinear regression of the data for both phenol and PCP adsorption with the Freundlich, Langmuir and BET equations generally gave more accurate parameters, compared with the use of linearized equations to obtain the parameters.

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