Co-composting of soil heavily contaminated with creosote with cattle manure and vegetable waste for the bioremediation of creosote-contaminated soil

摘要

Mispsh form (FAO: Lithosol) soil contaminated with >380 000 mg kg~(-1) creosote was co-composted with cattle manure and mixed vegetable waste for 19 months. The soil was mixed with wood chips to improve aeration and then mixed with cattle manure ormixed vegetable waste in a ratio of 4:1. Moisture, temperature, pH, ash content, C:N ratios, and the concentrations of creosote in the compost systems were monitored monthly. The concentrations of selected hydrocarbons in the compost systems were determined at the end of composting. Temperature rose to about 45 deg C in the cattle manure compost within two months of incubation while temperature in the control and vegetable waste remained below 30 deg C until the fourth month. Creosote concentration wasreduced by 17 percent in the control and by more than 99 percent in the cattle manure and vegetable waste compost after composting. The rate of reduction in concentration in the mixed vegetable waste compost was initially lower than in the cattle manurecompost. The reduction rate became similar in later months with only small differences towards the end of the composting. The concentrations of selected creosote components were reduced by between 96 percent and 100 percent after composting. There was nosignificant difference in reduction in concentration in both compost systems at p 0.05. Microbial activity correlated with reduction in creosote concentration.