Performance And Mechanism Degradation Of Phosphonate Of Hydroxylamine Enhanced Cu(Ⅱ) Activated Persulfate

Phosphonates is an important phosphorus-containing pollutant in water,which has attracted much attention due to its potential eutrophication and ecological risks.The phosphonates are difficult to remove directly and effectively by the conventional wastewater treatment methods.At present,the oxidation of phosphonates to orthophosphate(PO₄^3-)by advanced oxidation technology is the feasible means to removal.However,the advanced oxidation technology based on free radical system is easily disturbed by the matrix in water.Based on this,the paper use 1-hydroxyethane-1,1-diphosphonic acid（HEDP）as a model pollutant,which construct the Cu（Ⅱ）/PMS non-free radical system,and explores its performance and mechanism of degradation of HEDP.First,PMS was activated by the complexation of Cu（Ⅱ）and HEDP,which constructed a non-free radical system to explor the performance and mechanism.The results showed that 82%of HEDP was oxidized to PO₄^3-within 60 minutes.The production rate of PO₄^3-is higher in strong alkali conditions,because PMS mainly exists in the form of SO₅^-with low redox potential in strong alkali conditions,which is easier to promote the cycle of Cu（Ⅱ）/Cu（I）.Coexisting substances in water have little impact on the degradation of HEDP to PO₄^3-by Cu（Ⅱ）/PMS system,and the removal efficiency of HEDP in actual wastewater is much higher than other free radical systems（UV/H₂O₂,UV/PDS）in strong alkali conditions,which it has higher selectivity.The reason is that the intramolecular electron transfer of Cu（ⅡI）-HEDP complex is the main active oxidation species of HEDP degradation.Further study the functional relationship between the variable and response value of on the degradation of HEDP to PO₄^3-by Cu（Ⅱ）/PMS system.Use the response surface method to build a multiple regression model,the results show that the predicted value of the model is in good agreement with the actual value(R_adj²=0.9661).In order to broaden the p H response range of Cu（Ⅱ）/PMS system,constructed hydroxylamine hydrochloride（HAm）enhanced Cu（Ⅱ）/PMS system in neutral conditions to investigat performance and mechanism.The results showed that the degradation effect was the best when the molar ratio of PMS to HAm reached 3:1,85%of HEDP was oxidized to PO₄^3-within 15 minutes.Cu（Ⅱ）/PMS/HAm system has a wider p H range,which attributed to the t HAm can accelerate the cycle of Cu（Ⅱ）/Cu（I）.Coexisting substances in water have little impact on the degradation of HEDP to PO₄^3-by Cu（Ⅱ）/PMS/HAm system.In actual wastewater,the production rate of PO₄^3-is higher in neutral conditions.In the oxidation reaction of HEDP,the degradation of HEDP is mainly achieved through the combined action of Cu（ⅡI）induced intramolecular electron transfer and SO₄^·-.Further study the functional relationship between the variables on the degradation of HEDP to PO₄^3-by Cu（Ⅱ）/PMS/HAm system and the response value.Use the response surface method to build a multiple regression model,the results show that the predicted value of the model is in good agreement with the actual value(R_adj²=0.9289).The research structure further improved the reaction mechanism of C（Ⅱ）activated PMS degradation of phosphonates,and provided a new method and new idea for the efficient removal of phosphonates in actual wastewater.Figure 34 Table 14 Reference 145...