佛罗里达州西棕榈滩市（City）与棕榈滩县（Palm Beach County）联合开展了一个为期一年的示范项目，为按照间接饮用水回用标准处理二级废水提供成本和性能数据。该市使用了先进的污水处理（AWT）厂，该厂使用固体接触澄清器（SCC）和深床反硝化过滤器（DNF），然后进行氯消毒和湿地抛光。对于以西棕榈滩湿地为基础的水资源回收项目，预计经处理的废水将被输送至自然接收湿地，为供水井附近的表层含水层补给水。 因此，对污水质量进行了评估，以确保其符合三级水质标准和湿地防降解要求。在运行的第一年中，AWT出水的铁含量偶尔会超过1.0 mg/l的三级地表水质量标准。此外，出水总磷浓度远远超过潜在接收湿地的浓度。AWT废水中的铁和磷浓度可能会阻止或严重限制再生水在不添加新单元工艺的情况下应用于湿地。 在示范项目运行期间，观察到处理过程的几个特征，这些特征可能与AWT废水中的过量铁和磷浓度有关。根据AWT工厂的水质和工艺观察，认为优化混凝/絮凝/沉淀工艺需要采取两项措施:优化混凝和絮凝步骤，包括混凝类型、混凝剂量和混凝过程中的pH条件，以及确定对混凝/絮凝辅助聚合物和必要聚合物剂量的需求； 同时，尽量减少二级污水输送干管、INF和SCC中生物生长的可能性。

The City of West Palm Beach, Florida (City), in conjunction with Palm Beach County, operated a Demonstration Project over a one-year period to provide cost and performance data for treatment of secondary wastewater effluent to indirect potable reuse standards. The City utilized an Advance Wastewater Treatment (AWT) Plant that used a solids contact clarifier (SCC) and a deep bed denitrification filter (DNF) followed by chlorine disinfection and wetlands polishing. For the West Palm Beach Wetlands Based Water Reclamation Project, it is anticipated that the treated effluent will be routed to natural receiving wetlands that recharge the surficial aquifer in the vicinity of water supply wells. For this reason, the quality of the effluent was evaluated for compliance with Class III water quality standards and wetlands antidegradation requirements. Over the first year of operation, the AWT effluent occasionally exhibited elevated iron levels in excess of the Class III Surface Water Quality Standard of 1.0 mg/l. In addition the effluent total phosphorus concentrations were well in excess of the concentrations exhibited in the potential receiving wetlands. Such iron and phosphorus concentrations in the AWT effluent could prevent or severely restrict the application of the reclaimed water to the wetlands without the addition of new unit processes. During operation of the Demonstration Project, several characteristics of the treatment process were observed that were potentially related to the excessive iron and phosphorus concentration in the AWT effluent. Based upon the AWT Plant water quality and process observations, two actions were deemed necessary to optimize the coagulation/flocculation/sedimentation process: optimize the coagulation and flocculation step including coagulation type, coagulation dosage, and pH condition during coagulation as well as determine the need for a coagulation/flocculation aid polymer and necessary polymer dosage; and, minimize the potential for biological growth in the secondary effluent transmission main, INF, and SCC.