在台架和中试研究中，强化混凝和溶解气浮（DAF）将砷（As）的峰值浓度降低了50%至70%。DAF后的双介质过滤进一步将砷含量降低到2 pg/L的检测限以下。在小试和中试期间调查的因素包括三氯化铁剂量、混凝pH值、絮凝时间、DAF水力负荷率和进水砷浓度。控制砷去除的主要驱动因素是混凝剂剂量，最佳去除量为8至10 mg/L氯化铁（FeC13）。在本研究评估的条件下，混凝pH（6.5至7.5）、混凝时间（8至16分钟）和DAF水力加载速率（5至9 gpmKt2）对砷去除效率没有显著影响。增加三氯化铁去除砷的剂量会增加产生的污泥总质量和从水中去除的砷总质量。 然而，残渣中砷的浓度（mg/kg污泥）实际上降低了。中试污泥的TCLP结果为<0。0002 mg/L砷，远低于5 mg/L砷TCLP要求。污泥砷含量明显高于联邦503土地使用限制（41 mg/kg），从而限制了污泥处置的替代方案。包括表格、数字。

Enhanced coagulation and dissolved air flotation (DAF) reduced spiked arsenic (As) concentrations by 50 to 70 percent during bench and pilot studies. Dual media filtration following DAF further reduced arsenic levels to below the detection limit of 2 pg/L as As. Factors investigated during bench and pilot trials included ferric chloride dose, coagulation pH, flocculation time, DAF hydraulic loading rate, and influent arsenic concentration. The major driver controlling arsenic removal was coagulant dose, with optimum removal occurring at about 8 to 10 mg/L ferric chloride as FeC13. Under conditions evaluated in this work, coagulation pH (6.5 to 7.5), flocculation time (8 to 16 minutes), and DAF hydraulic loading rate (5 to 9 gpmKt2) did not significantly impact arsenic removal efficiency. Increasing ferric chloride dose for arsenic removal increased the total mass of sludge produced and the total mass of arsenic removed from the water. However, the concentration of arsenic in the residuals (mg As per kg sludge) actually decreased. TCLP results of pilot generated sludge were <0.0002 mg/L as As, well below the 5 mg/L arsenic TCLP requirement. Sludge arsenic levels were markedly higher than the Federal 503 land application limit of 41 mg/kg, thereby limiting sludge disposal alternatives. Includes tables, figures.