Use of rapid small-scale column tests for simultaneous prediction of phosphorus and nitrogen retention in large-scale filters

•Modelling small column tests predicted DRP and NH4-N concentrations in large columns.•The order of packing the media did not influence adsorption or modelling outcomes.•Moving to small scale tests provides operational, financial and labour savings.•RSSCT generated modelling parameters for simultaneous nutrient remediation in drainage waters.•Simultaneous modelling of DRP and NH4-N was based on second order kinetics.