Author
LERTPAITOONPAN, WARISARA - Sripatum University | |
Moorman, Thomas | |
ONG, SAY KEE - Iowa State University |
Submitted to: Water, Air, and Soil Pollution
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/22/2014 Publication Date: 2/25/2015 Citation: Lertpaitoonpan, W., Moorman, T.B., Ong, S. 2015. Effect of swine manure on sulfamethazine degradation in aerobic and anaerobic soils. Water, Air, and Soil Pollution. 226:81-93. Interpretive Summary: Antibiotics are used in the production of swine and beef cattle and enter soil when animal manure is applied. We compared the degradation sulfamethazine (SMZ) in aerobic and anaerobic (oxygen free) soil with and without swine manure. SMZ, at initial concentrations of 0.5 and 5 ppm (parts per million), disappeared rapidly under aerobic and anaerobic conditions with initial half-lives of less than two days. Disappearance of SMZ at 50 and 100 ppm was slower, with initial half-lives of 3.3 and 6.6 days in aerobic soils, respectively. Swine manure had little effect on persistence of SMZ. The initial half-lives in anaerobic soil with initial SMZ concentrations of 50 and 100 mg-1 kg soil, were greater than in aerobic soil, reaching 9.1 and > 63 days, respectively. After the initial period of rapid disappearance, SMZ loss slowed and became more persistent. In soils receiving 100 mg kg-1 of SMZ, between 25 and 60% of the SMZ was still present after 63 days. Inhibitory effects of SMZ on anaerobic microbial respiration were observed in unamended soil at concentrations of 50 mg kg-1 or higher, but only transient inhibitory effects were found in aerobic soil. Seventy to 91% of the SMZ was converted to bound (non-extractable) forms in both manure amended and unamended soil. Disappearance of SMZ in sterilized soil was slowed, but not halted, indicating that both biological and chemical processes contribute to the dissipation of SMZ. This information will be useful to environmental scientists in determining the possible environmental risk posed by antibiotics in animal manure. Technical Abstract: The degradation and fate of sulfamethazine (SMZ) were determined under aerobic and anaerobic conditions in soil with and without swine manure amendment. SMZ, at initial concentrations of 0.5 and 5 mg kg-1, disappeared rapidly under aerobic and anaerobic conditions with initial half-lives of less than two days. Disappearance of SMZ at 50 and 100 mg kg-1 soil was slower, with initial half-lives of 3.3 and 6.6 days in aerobic soils,respectively. Swine manure (0.054 g g-1 soil) had little effect on persistence of SMZ. The initial half-lives in anaerobic soil with initial SMZ concentrations of 50 and 100 mg-1 kg soil, were greater than in aerobic soil, reaching 9.1 and > 63 days, respectively. After the initial period of rapid disappearance, SMZ loss slowed and became more persistent. In soils receiving 100 mg kg-1 of SMZ, between 25 and 60% of the SMZ was still present after 63 days. Inhibitory effects of SMZ on anaerobic microbial respiration were observed in unamended soil at concentrations of 50 mg kg-1 or higher, but only transient inhibitory effects were found in aerobic soil. Seventy to 91% of 14C[phenyl]-SMZ was converted to bound (non-extractable) forms in both manure amended and unamended soil. Between 5 and 10% of the 14C-SMZ was in the form of metabolites while only 0.1 to 1.5% of 14C-SMZ was mineralized to 14CO2. Disappearance of SMZ in sterilized soil was slowed, but not halted, indicating that both biotic and abiotic processes contribute to the dissipation of SMZ. |