Fe(II)-tetrapolyphosphate complexes are known to activate molecular oxygen (Fe(II)-TPP/O₂) to produce reactive oxidants (most likely, Fe(IV)-TPP complexes) that are capable of degrading refractory organic contaminants in water. This study found that magnesium and calcium ions (Mg²⁺ and Ca²⁺) accelerate the degradation of micfrocystin-LR (MC-LR), the most toxic and abundant cyanotoxin, by the Fe(II)-TPP/O₂ system. The addition of Mg²⁺ and Ca²⁺ increased the observed rate constant of MC-LR degradation by up to 4.3 and 14.8 folds, respectively. Mg²⁺ and Ca²⁺ accelerated the MC-LR degradation in the entire pH range, except for the alkaline region with pH > ca. 10. The addition of Mg²⁺ and Ca²⁺ also reshaped the pH-dependency of the MC-LR degradation, greatly increasing the rate of MC-LR degradation at neutral pH. It was found that Mg²⁺ and Ca²⁺ accelerate the reaction of Fe(II)-TPP complexes with oxygen, resulting in faster production of reactive oxidants. The findings from cyclic voltammetry and potentiometric titration suggest that Mg²⁺ and Ca²⁺ form ternary complexes with Fe(II)-TPP, which exhibit higher reactivity with oxygen. Due to the effects of Mg²⁺ and Ca²⁺, the rate of MC-LR degradation by the Fe(II)-TPP/O₂ system was even higher in natural water than in deionized water.

已知Fe（II）-四聚磷酸盐复合物可活化分子氧（Fe（II）-TPP / O ₂）产生能降解水中难降解有机污染物的活性氧化剂（极有可能是Fe（IV）-TPP复合物） 。这项研究发现，镁和钙离子（Mg ²⁺和Ca ²⁺）可通过Fe（II）-TPP / O ₂系统加速最具毒性和最丰富的蓝藻毒素微丝藻毒素（MC-LR）的降解。Mg ²⁺和Ca ^2+的添加使观察到的MC-LR降解速率常数分别增加了4.3倍和14.8倍。Mg ²⁺和Ca ²⁺在整个pH范围内加速了MC-LR的降解，除了pH> ca的碱性区域。10. Mg ²⁺和Ca ^2+的添加还改变了MC-LR降解的pH依赖性，从而大大提高了中性pH时MC-LR的降解速率。发现Mg ²⁺和Ca ²⁺加速Fe（II）-TPP配合物与氧气的反应，导致更快地产生反应性氧化剂。循环伏安法和电位滴定法的发现表明，Mg ²⁺和Ca ²⁺与Fe（II）-TPP形成三元络合物，与氧的反应性更高。由于Mg ²⁺和Ca ^2+的影响，Fe（II）-TPP / O ₂系统在自然水中的MC-LR降解速率甚至比去离子水中更高。