Microcosm test for pesticide fate assessment in planted water filters: 13C,15N-labeled glyphosate as an example

•A microcosm test for chemical fate analysis in planted filters was developed.•Mass balance of the model 13C,15N-pesticide glyphosate fate was established.•Glyphosate was mainly adsorbed on gravel in the microcosms.•Plants promoted glyphosate mineralization and microbial assimilation of 13C and 15N.•Microcosm test is simple & feasible for fate analysis of non-volatile chemicals.