Lejwoda Paweł, Białecka Barbara, Śliwińska Anna, Krawczyk Piotr, Thomas Maciej
Department of Energy Saving and Air Protection, Central Mining Institute in Katowice, Plac Gwarków 1, 40-166 Katowice, Poland.
Department of Environmental Monitoring, Central Mining Institute in Katowice, Plac Gwarków 1, 40-166 Katowice, Poland.
Molecules. 2025 Aug 20;30(16):3428. doi: 10.3390/molecules30163428.
This article presents an innovative method for phosphate(V) removal from industrial wastewater using cerium(III) chloride as a coagulant, integrated with reagent recovery. The process combines coagulation, acid extraction, and multistage recovery of cerium and phosphorus, enabling partial reagent loop closure. Based on our previously published studies, at an optimised dose (81.9 mg Ce/L), phosphate(V) removal reached 99.86% and total phosphorus (sum of all phosphorus forms as elemental P), 99.56%, and 99.94% of the added cerium was retained in sludge. Reductions were also observed for TSS (96.67%), turbidity (98.18%), and COD (81.86%). The sludge (101.5 g Ce/kg, 22.2 g P/kg) was extracted with HCl, transferring 99.6% of cerium and 97.5% of phosphorus to the solution. Cerium was recovered as cerium(III) oxalate and thermally decomposed to cerium(IV) oxide. Redissolution in HCl and HO yielded cerium(III) chloride (97.0% recovery and 98.6% purity). The HCl used for extraction can be regenerated on-site from chlorine and hydrogen obtained from gas streams, improving material efficiency. Life cycle assessment (LCA) showed environmental benefits related to eutrophication reduction but burdens from reagent use (notably HCl and oxalic acid). Although costlier than conventional precipitation, this method may suit large-scale applications requiring high phosphorus removal, low sludge, and alignment with circular economy goals.
本文介绍了一种创新方法，该方法使用氯化铈作为混凝剂从工业废水中去除磷酸根（V），并集成了试剂回收。该工艺结合了混凝、酸萃取以及铈和磷的多级回收，实现了部分试剂循环闭合。基于我们之前发表的研究，在优化剂量（81.9 mg Ce/L）下，磷酸根（V）的去除率达到99.86%，总磷（以元素P计的所有磷形态之和）的去除率为99.56%，并且99.94%的添加铈保留在污泥中。总悬浮固体（TSS，96.67%）、浊度（98.18%）和化学需氧量（COD，81.86%）也有所降低。用盐酸萃取污泥（101.5 g Ce/kg，22.2 g P/kg），将99.6%的铈和97.5%的磷转移到溶液中。铈以草酸铈（III）的形式回收，并热分解为二氧化铈（IV）。重新溶解于盐酸和水中得到氯化铈（III）（回收率97.0%，纯度98.6%）。用于萃取的盐酸可从气流中获得的氯气和氢气现场再生，提高了材料效率。生命周期评估（LCA）表明该方法在减少富营养化方面具有环境效益，但在试剂使用（特别是盐酸和草酸）方面存在负担。尽管该方法比传统沉淀法成本更高，但可能适用于需要高磷去除率、低污泥产量且符合循环经济目标的大规模应用。
