Compost bioreactors for removing agricultural chemicals from tile drainage water.

摘要

The overall purpose of this study was to examine the feasibility of using compost to remove agricultural chemicals from solution. Several compost samples were initially screened for their affinity to sorb the herbicide atrazine. Compost samples from Northfield, Illinois, the Urbana Landscape Recycling Center (ULRC), and Illinois State University (ISU) were chosen for detailed studies. The Northfield compost sample was pyrolyzed under air or N2 at different temperatures to produce activated chars. The chars heated under air had a greater affinity for atrazine than chars heated under N 2 at the same temperature. In general, the chars affinity for atrazine increased with increasing pyrolysis temperature.; Compost age and the addition of nutrient sources to the compost could have significant impacts on the extent of atrazine removal from solution. Among ULRC samples of different ages, a 6-month-old compost had the greatest capacity for removing atrazine from solution, which was attributed to its greater organic carbon content. Adding nitrate enhanced the capacity of ULRC compost to remove atrazine from solution. The addition of nitrate did not have a significant impact on atrazine removal when applied to the ISU compost, probably because manure was added to the yard waste to produce the compost. When compared with the ISU compost, the ULRC compost sample had a greater capacity to remove atrazine from solution during the 120 days of study because of the larger humic acid content.; The 6-month-old compost was also examined for its capacity to promote denitrification in column studies. The extent of nitrate removal depended on the solid retention time, but could also have been influenced by the amount of compost in the column that could be utilized as an energy source by denitrifying microorganisms. The results of this study suggested that relatively immature compost may have a better potential for several environmental applications than the mature compost commonly used in traditional agricultural applications.