Optimal Recipe Assessment of Iron Filing-Based Green Environmental Media for Improving Nutrient Removal in Stormwater Runoff

摘要

Nutrient removal and recovery (NRR) technology was investigated using green sorption media with respect to 4 distinct clay and iron filing quantities in the media matrix. Column study tests were conducted to analyze distinct percentage clay contents (2%, 4%, 6%, and 8%) and iron filing contents (2.5%, 5%, 7.5%, and 10%) from a total of seven sorption media recipes. Through this effort, the optimal recipe of iron filing-based green environmental media (IFGEM) for stormwater runoff treatment was determined to be composed of 2% clay, 83% sand, 10% tire crumb, and 5% iron filing content by volume within the NRR technology hub. Removal efficiencies of total nitrogen (TN) and total phosphorus (TP) as well as ammonia recovery potential were thoroughly investigated and realized. Parameters such as NOx, ammonia, oxidation/reduction potential, pH, and dissolved oxygen were recorded for integrative analysis. Higher ammonia removal efficiency (98%) was observed for the influent condition (0.9 mg/L NO3−, 0.3 mg/L PO43−) with the lowest nutrient concentrations, while higher TN (94%) and TP (92%) removal was achieved for the influent condition (1.7 mg/L NO3−, 0.7 mg/L PO43−) with the largest nutrient concentration. The synergistic effect of clay and iron filing within the optimal recipe of IFGEM was realized for final justification of possible nutrient recovery.