Faculty of Civil and Industrial Engineering, Department of Civil, Constructional and Environmental Engineering (DICEA), Sapienza University of Rome, Via Eudossiana 18, Zip code 00184, Rome, Italy E-mail:
Acqualatina S.p.A, Viale P. L. Nervi snc-C.Com, Latinafiori - Torre 10 Mimose, 04100 Latina, Italy.
Water Sci Technol. 2020 Apr;81(7):1329-1335. doi: 10.2166/wst.2020.023.
Chemical precipitation with the addition of ferric chloride is commonly used to remove phosphorus from wastewater. However, since its application also involves several disadvantages, alternative solutions are required. The present paper shows the results of a full-scale experimental work aimed at evaluating the efficiency of the ion exchange process using a polymeric anion exchange resin impregnated with aluminum ions in the removal of phosphorus from wastewater. The study compared the results obtained through this process with chemical precipitation, considering both technical and economic issues. At the same dosage of 6 L/hour and influent concentration (about 6 mg/L), total removal efficiency of 95% and 78% (including also that occurring in the mechanical and biological processes) was achieved by means of the anion exchange process and chemical precipitation, respectively. However, in the latter case, this value was insufficient to ensure consistent compliance with the limit of 2 mg/L P set on the effluent; to achieve this goal, the ferric chloride dosage had to be raised to 12 L/hour, thus increasing the related costs. Furthermore, the anion exchange process generated a lower sludge production. Therefore, the ion exchange process represents a valid alternative to chemical precipitation for P removal from wastewater.
化学沉淀法（加入三氯化铁）常用于去除废水中的磷。然而，由于其应用还涉及一些缺点，因此需要替代解决方案。本文展示了一项全规模实验工作的结果，该工作旨在评估用离子交换法去除废水中磷的效果，使用的是一种浸渍有铝离子的聚合物阴离子交换树脂。该研究从技术和经济角度比较了该过程与化学沉淀法的结果。在相同的剂量为 6 升/小时和进水浓度（约 6 毫克/升）下，阴离子交换过程的总去除效率为 95%，而化学沉淀法的总去除效率为 78%（包括机械和生物过程中的去除率）。然而，在后一种情况下，这一数值不足以确保持续符合规定的 2 毫克/升 P 的出水限值；为了达到这一目标，必须将三氯化铁的剂量提高到 12 升/小时，从而增加了相关成本。此外，阴离子交换过程产生的污泥量更少。因此，离子交换法是去除废水中磷的一种替代化学沉淀法的有效方法。
