To make up the gap of wasted phosphonates being too much as pollutants and phosphorus being too little as a natural resource, electrochemical “oxidation-precipitation” system was rationally developed to recover phosphorus with simultaneous mineralization of ethylenediamine tetra(methylene phosphonic acid) (EDTMP), a typical phosphonate. In this process, BDD(^•OH) was the primary oxidative species for EDTMP degradation, which led to the bond cleavage in the sequence of C-N, C-P and C-C. Increasing current density from 3 to 30 mA cm^-2 improved the mineralization efficiency of EDTMP from 14% to 72% within 120 min, accompanying 65%-95% of EDTMP conversion to orth-P. With the presence of 50 mg L^-1 Ca²⁺, 21%-83% of phosphorus was recovered as insoluble calcium phosphate at the cathode surface. High initial Ca²⁺ concentration favored the phosphorus recovery, whereas it was negatively influenced with the presence of Mg²⁺ and HCO₃^-. In addition, phosphorus recovery was negligibly affected by solution pH in the range of 3.0 to 12.0 because the locally alkaline condition was well maintained at the cathode surface. Phosphorus was electrochemically recovered mainly in the form of thermodynamically most stable hydroxyapatite, which proceeded via the formation of brushite, octacalcium phosphate, and amorphous calcium phosphate with Δ[Ca]/Δ[P] molar ratio increasing from 1.0 to 1.67. Based on the results of phosphorus recovery from the real wastewater, we envision that this synchronous anodic oxidation-cathodic precipitation process can be applied as an environmentally compatible and feasible strategy for phosphorus recovery from the phosphonate wastewaters.

为了弥补浪费的膦酸盐与污染物的过多以及磷作为自然资源的不足的差距，合理地开发了电化学“氧化沉淀”系统来回收磷，同时乙二胺四亚甲基膦酸（EDTMP）矿化，典型的膦酸酯。在此过程中，BDD（^• OH）是EDTMP降解的主要氧化物质，导致CN，CP和CC序列的键断裂。从3到30 mA cm ^-2的电流密度增加，在120分钟内将EDTMP的矿化效率从14％提高到72％，伴随着EDTMP转化为邻位P的比例达到65％-95％。存在50 mg L ^-1 Ca ²⁺，在阴极表面回收了21％-83％的磷作为不溶性磷酸钙。高的初始Ca ²⁺浓度有利于磷的回收，而Mg ²⁺和HCO _3-的存在对磷的回收有负面影响^。。另外，溶液pH值在3.0至12.0的范围内，磷的回收率可忽略不计，因为在阴极表面良好地维持了局部碱性条件。电化学方式回收的磷主要以热力学最稳定的羟基磷灰石的形式发生，该过程通过透钙磷矿，八磷酸钙和无定形磷酸钙的形成进行，Δ[Ca] /Δ[P]的摩尔比从1.0增加到1.67。基于从实际废水中回收磷的结果，我们设想这种同步阳极氧化-阴极沉淀过程可以用作从膦酸酯废水中回收磷的环境兼容且可行的策略。