Intermittently Decanted Extended Aeration (IDEA) processes are widely used for wastewater treatment. However, in-depth performance evaluation of a full-scale IDEA plant is rare, making it challenging for water utilities to meet the increasingly stringent discharge requirements with these assets. This study aims to fill this gap through a comprehensive assessment of nitrogen and phosphorus removal in a full-scale IDEA plant in Australia. The plant consists of two identical IDEA tanks operated in-parallel. Upstream to each tank is a bioselector with four interlinked compartments. We conducted an eight-week monitoring program with four intensive cyclic studies to establish detailed nutrient profiles of the two IDEA tanks to assess the performance of nitrogen and alum assisted phosphorus removal. Results showed that the plant enabled good nitrification in the IDEA effluent. However, the denitrification efficiency was low (ca. 50%), and could be improved by decreasing oxygen supply to suppress nitrite oxidation and preserve influent carbon. The addition of alum to the IDEA tank appeared to be ineffective given the low P concentration (<1 mg-P/L) in the tank. The bioselector was identified as a better alum-dosing location, given its higher (~7-fold) phosphate concentration in comparison to the influent. Stopping the dosing of alum only marginally increased the effluent P (0.35 to 0.52 mg-P/L), implying that P removal was predominantly (94%) biologically mediated and achieved via P accumulating microorganisms. Overall, this study offers timely and useful process understanding of the performance of IDEA plants, as well as other similar wastewater treatment configurations.

间歇倾析扩展曝气（IDEA）工艺被广泛用于废水处理。但是，很少有一家大型IDEA工厂进行深入的性能评估，这使得自来水公司要用这些资产来满足日益严格的排放要求具有挑战性。这项研究旨在通过对澳大利亚一家大型IDEA工厂中脱氮除磷的综合评估来填补这一空白。该工厂由两个并行运行的相同IDEA储罐组成。每个储罐的上游是一个生物选择器，具有四个相互连接的隔室。我们进行了为期八周的监测计划，并进行了四次深入的循环研究，以建立两个IDEA储罐的详细营养状况，以评估氮和明矾辅助除磷的性能。结果表明，该工厂在IDEA废水中实现了良好的硝化作用。但是，反硝化效率低（约50％），可以通过减少氧气供应来抑制亚硝酸盐氧化并保留进水碳来提高反硝化效率。考虑到罐中低P浓度（<1 mg-P / L），向IDEA罐中添加明矾似乎无效。由于生物选择器的磷酸盐浓度比进水高（约7倍），因此被确定为更好的明矾配药位置。停止施用明矾只会稍微增加废水中的磷（0.35至0.52 mg-P / L），这意味着磷的去除主要（94％）是由生物介导的，并且是通过积累磷的微生物实现的。总体而言，这项研究为IDEA工厂的性能提供了及时而有用的过程理解，