@article{BarkowOswaldLensingetal.2020,
  author    = {Barkow, Isolde S. and Oswald, Sascha Eric and Lensing, Hermann Josef and Munz, Matthias},
  title     = {Seasonal dynamics modifies fate of oxygen, nitrate, and organic micropollutants during bank filtration},
  series = {Environmental science and pollution research : official organ of the EuCheMS Division for Chemistry and the Environment, EuCheMS DCE},
  volume    = {28},
  journal   = {Environmental science and pollution research : official organ of the EuCheMS Division for Chemistry and the Environment, EuCheMS DCE},
  number    = {8},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0944-1344},
  doi       = {10.1007/s11356-020-11002-9},
  pages     = {9682 -- 9700},
  year      = {2020},
  abstract  = {Bank filtration is considered to improve water quality through microbially mediated degradation of pollutants and is suitable for waterworks to increase their production. In particular, aquifer temperatures and oxygen supply have a great impact on many microbial processes. To investigate the temporal and spatial behavior of selected organic micropollutants during bank filtration in dependence of relevant biogeochemical conditions, we have set up a 2D reactive transport model using MODFLOW and PHT3D under the user interface ORTI3D. The considered 160-m-long transect ranges from the surface water to a groundwater extraction well of the adjacent waterworks. For this purpose, water levels, temperatures, and chemical parameters were regularly measured in the surface water and groundwater observation wells over one and a half years. To simulate the effect of seasonal temperature variations on microbial mediated degradation, we applied an empirical temperature factor, which yields a strong reduction of the degradation rate at groundwater temperatures below 11 degrees C. Except for acesulfame, the considered organic micropollutants are substantially degraded along their subsurface flow paths with maximum degradation rates in the range of 10(-6) mol L-1 s(-1). Preferential biodegradation of phenazone, diclofenac, and valsartan was found under oxic conditions, whereas carbamazepine and sulfamethoxazole were degraded under anoxic conditions. This study highlights the influence of seasonal variations in oxygen supply and temperature on the fate of organic micropollutants in surface water infiltrating into an aquifer.},
  language  = {en}
}
@article{WangOswaldGraeffetal.2019,
  author    = {Wang, Wei-shi and Oswald, Sascha Eric and Gr{\"a}ff, Thomas and Lensing, Hermann Josef and Liu, Tie and Strasser, Daniel and Munz, Matthias},
  title     = {Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport},
  series = {Hydrogeology journal : official journal of the International Association of Hydrogeologists},
  volume    = {28},
  journal   = {Hydrogeology journal : official journal of the International Association of Hydrogeologists},
  number    = {2},
  publisher = {Springer},
  address   = {Berlin ; Heidelberg [u.a.]},
  issn      = {1431-2174},
  doi       = {10.1007/s10040-019-02063-3},
  pages     = {723 -- 743},
  year      = {2019},
  abstract  = {Bank filtration (BF) is an established indirect water-treatment technology. The quality of water gained via BF depends on the subsurface capture zone, the mixing ratio (river water versus ambient groundwater), spatial and temporal distribution of subsurface travel times, and subsurface temperature patterns. Surface-water infiltration into the adjacent aquifer is determined by the local hydraulic gradient and riverbed permeability, which could be altered by natural clogging, scouring and artificial decolmation processes. The seasonal behaviour of a BF system in Germany, and its development during and about 6 months after decolmation (canal reconstruction), was observed with a long-term monitoring programme. To quantify the spatial and temporal variation in the BF system, a transient flow and heat transport model was implemented and two model scenarios, 'with' and 'without' canal reconstruction, were generated. Overall, the simulated water heads and temperatures matched those observed. Increased hydraulic connection between the canal and aquifer caused by the canal reconstruction led to an increase of similar to 23\% in the already high share of BF water abstracted by the nearby waterworks. Subsurface travel-time distribution substantially shifted towards shorter travel times. Flow paths with travel times <200 days increased by similar to 10\% and those with <300 days by 15\%. Generally, the periodic temperature signal, and the summer and winter temperature extrema, increased and penetrated deeper into the aquifer. The joint hydrological and thermal effects caused by the canal reconstruction might increase the potential of biodegradable compounds to further penetrate into the aquifer, also by potentially affecting the redox zonation in the aquifer.},
  language  = {en}
}