Journal article

Publication year: 2014

Pages: 1926-1932

Journal: Journal of Environmental Quality

Volume number: 43

Issue number: 6

ISSN: 0047-2425

DOI Link: https://doi.org/10.2134/jeq2013.11.0475

Publisher: Wiley

Abstract: 
Wastewater irrigation is often performed by flood irrigation, leading to changes in redox potential (Eh) of irrigated soils. In addition to soil organic matter, Fe-(hydr) oxides are important sorbents for pollutants, and biotransformation of pollutants can be accelerated under reducing conditions. Here, the influence of reducing conditions on the release of sorbed pharmaceuticals from soil and their potential accelerated dissipation was investigated in a microcosm study. Samples of a soil from the Mezquital Valley (Mexico) irrigated for 85 yr with untreated wastewater were incubated under oxidizing (Eh of 500 +/- 20 mV), weakly reducing (Eh of 100 +/- 20 mV), and moderately reducing (Eh of -100 +/- 20 mV) soil conditions for 30 to 31 d. The concentrations of nine pharmaceuticals (bezafibrate, carbamazepine, ciprofloxacin, sulfamethoxazole, trimethoprim, enrofloxacin, clarithromycin, diclofenac, and naproxen) were extracted via solid-phase extraction from soil slurries and analyzed by liquid chromatography-tandem mass spectrometry. Low Eh did not lead to a release of formerly sorbed pharmaceuticals from the wastewater irrigated soil. High pH values (> 8) of the examined soil resulting from denitrification under reducing conditions prevented the dissolution of Fe-(hydr) oxides and, hence, the potential release of pharmaceuticals. A trend of decreasing concentrations of sulfamethoxazole and bezafibrate with time under moderately reducing conditions supports previous findings of a transformation of these compounds under anaerobic conditions.

Harvard Citation style: Dalkmann, P., Dresemann, T., Siebe, C., Mansfeldt, T., Amelung, W. and Siemens, J. (2014) Release of Pharmaceuticals under Reducing Conditions in a Wastewater-Irrigated Mexican Soil, Journal of Environmental Quality, 43(6), pp. 1926-1932. https://doi.org/10.2134/jeq2013.11.0475

APA Citation style: Dalkmann, P., Dresemann, T., Siebe, C., Mansfeldt, T., Amelung, W., & Siemens, J. (2014). Release of Pharmaceuticals under Reducing Conditions in a Wastewater-Irrigated Mexican Soil. Journal of Environmental Quality. 43(6), 1926-1932. https://doi.org/10.2134/jeq2013.11.0475