STRAW COMPOST AND BIOREMEDIATED SOIL AS INOCULA FOR THE BIOREMEDIATION OF CHLOROPHENOL-CONTAMINATED SOIL

We evaluated the use of straw compost and remediated soil as inocula f or bioremediation of chlorophenol-contaminated soil, The in situ biotr ansformation of pentachlorophenol (PCP) and mineralization of radiolab eled [U-C-14]PCP by straw compost and remediated soil were studied und er field-simulating conditions before and after 3 months of adaptation with PCP in a percolator. After PCP adaptation, the straw compost min eralized up to 56% of the [C-14]PCP, No partial dechlorination of PCP was found. The native straw compost did not mineralize PCP, but partia l dechlorination of PCP occurred (i) at pH 8 under near-thermophilic c onditions (45 degrees C) and (ii) at pH 7 under aerobic and mesophilic conditions, No biotransformation reactions occurred at room temperatu re (25 degrees C) at pH 8, Enrichment in the percolator enhanced the m ineralization rate of remediated soil to 56% compared with that of the native remediated soil, which mineralized 24% of [C-14]PCP added, Tra ce amounts of chloroanisoles as the only biotransformation products we re detected in PCP-adapted remediated soil, Both inoculants studied he re showed effective mineralization of PCP when they were adapted to PC P in the percolator. No harmful side reactions, such as extensive meth ylation, were observed.