Evaluation of electric arc furnace slag as a potential phosphate-removal substrate

A study was conducted to evaluate the performance of locally available electric arc furnace slag (EAFS) as a substrate for removing phosphorus from wastewater. First, in a laboratory study, EAFS was found to have high phosphorus removal efficiency for three P concentrations (0.3, 3.0, and 6.0 mg/L); this resulted in nearly 100% phosphorus removal in 24 h. Next, the experiment was repeated using aeration and similar phosphorus removal was observed but in a shorter contact time of 1 h. The adsorption capacity of EAFS was determined to be 1,458 mg/kg. In a pilot-scale study, over 90% P removal took place in the first 4 h under nonaerated conditions, and nearly 100% removal in 8 h. While the P removal with aeration was relatively less initially for the shorter residence times, a 100% removal was observed for the 24-h residence time. DOI: 10.1061/(ASCE)EE.1943-7870.0000158 CE Database subject headings: Phosphorus; Abatement and removal; Laboratory tests; Adsorption; Phosphate; Wastewater management. Author keywords: Electric arc furnace slag (EAFS); Phosphorus removal; Laboratory study; Pilot study; Adsorption capacity; Residence time.