We congratulate Anna-Lisa Dittrich on her master thesis "The impact of woodchips and biochar on nutrient retention in agricultural streams". She successfully defended it on March 17, 2023 under the supervision of Gabriele Weigelhofer at BOKU. Her work was carried out at WasserCluster Lunz and deals with the use of bioreactors made of woodchips or activated carbon for the removal of dissolved nitrogen from agriculturally polluted waters.