SP 2: Release and dissipation of antibiotics and disinfectants in different soil types as influenced by irrigation water quality
Background
Irrigation with untreated wastewater in the past resulted in an accumulation of chemical pollutants like pharmaceutical residues and disinfectants in soils. These pollutants might be released into soil water when untreated wastewater is replaced with treated wastewater for irrigation.
Hypotheses
We hypothesize that this shift will transiently
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trigger the release of legacy pollutants from soil back into soil water
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lead to environmental concentrations of antibiotics and disinfectants that are large enough to promote the selection of antibiotic resistance, with
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release and concentrations of antibiotics depending on soil type.
Methods
Time series of concentrations of antibiotics and disinfectants of different bio-accessibility for assessment of dissipation and sequestration dynamics with a kinetic fate model (SP 7).
Artificial sinks (diffusive gradients in thin films) and isotope exchange experiments to quantify desorption kinetics and size of desorbable pollutant pool.
Concentrations of pharmaceuticals and disinfectants in soils and plants irrigated with irrigation water with an increasing share of treated wastewater.
Bio-accessible and dissolved pollutant concentrations are related to minimum selective concentrations (SP 3), abundance of antibiotic resistance genes and microbial community (SP 4, SP 5) and fractions of cultivable resistant bacteria (SP 6).
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| Benjamin Justus Heyde (post doc) | Jan Siemens (PI) | Ines Mulder (PI) |