A novel photo-assisted activated persulfate strategy for selective oxidation of ammonia nitrogen to dinitrogen using sodium silicate and sodium sulfite as regulators

被引：6

作者：

Zhang, Le ^{[1
]}

Liu, Ting ^{[1
]}

Zhu, Meng ^{[1
,2
]}

Liu, Yong ^{[1
,2
,3
,4
]}

机构：

[1] Sichuan Normal Univ, Coll Chem & Mat Sci, Chengdu 610066, Peoples R China

[2] Key Lab Treatment Special Wastewater Sichuan Prov, Chengdu 610066, Sichuan, Peoples R China

[3] Sichuan Normal Univ, Key Lab Land Resources Evaluat & Monitoring Southw, Minist Educ, Chengdu 610066, Peoples R China

[4] Jingan Rd 5, Chengdu 610066, Sichuan, Peoples R China

来源：

CHEMICAL ENGINEERING JOURNAL | 2024年 / 479卷

基金：

中国国家自然科学基金;

关键词：

Ammonia nitrogen; Persulfate; Sulfite; Sodium silicate; Denitrification; WASTE-WATER; DEGRADATION; REMOVAL; FENTON;

D O I：

10.1016/j.cej.2023.147542

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Persulfate (PS)-based advanced oxidation processes (SR-AOPs) is a promising approach for the removal of ammonia nitrogen (NH3-N) from wastewater, but it suffered from the low removal efficiency and the excessive oxidation of NH3-N to nitrate (NO3-) or nitrite (NO2-) in the absence of in-situ generated chlorine radicals. Therefore, it is still a challenge to improve the efficiency of NH3-N removal and the selectivity of NH3-N oxidation products towards dinitrogen (N-2) by SR-AOPs without chlorine radicals. Herein, a novel photo-assisted activation of SR-AOPs involving sodium silicate (Na2SiO3) and sodium sulfite (Na2SO3) was developed for NH3-N removal from wastewater. In this system, Na2SiO3 was acted as a green buffer to maintain NH3-N in the form of un-ionized ammonia (NH3) with strong reducibility, promoting the efficiency of NH3-N removal as well as ensuring the neutral effluent by receiving the H+ from PS activation. Na2SO3 could inhibit the excessive oxidation of NH3-N by regulating the redox potential of the solution and generating hydrated electrons (e(aq)(-)) under light (hv) irradiation, enhancing the selectivity of NH3-N oxidation products towards N-2. 100 % of NH3-N removal efficiency and more than 98 % of N-2 selectivity were obtained after 30 min at the initial pH of 3-9 and the initial NH3-N concentration of 30 mg N/L. Based on the quenching experiment, EPR test and probe experiment, the HO center dot and SO4 center dot- were the main reactive oxygen species (ROS) to be responsible for NH3-N oxidation. This study proposed a new approach for treatment of wastewater containing NH3-N by SR-AOPs.

引用

页数：11