Batch experiment samples (solids and aqueous) were analyzed both on-site and at the University of Illinois Urbana-Champaign (UIUC). Handheld probes were used to measure pH (Orion 3-Star portable pH meter; Thermo Scientific), temperature and DO (Orion RDO dissolved oxygen probe; Thermo Scientific), and ammonium concentrations (ProDSS multiparameter digital water quality meter; YSI); each sensor was calibrated immediately prior to use in the bench-scale experiments.