Efficient ammonia removal and toxic chlorate control by using BiVO4/WO3 heterojunction photoanode in a self-driven PEC-chlorine system
Efficient ammonia removal and toxic chlorate control by using BiVO4/WO3 heterojunction photoanode in a self-driven PEC-chlorine system
复制标题
在自驱动 PEC-氯系统中使用 BiVO4/WO3 异质结光电阳极有效去除氨并控制有毒氯酸盐
DOI：
10.1016/j.jhazmat.2020.123725
复制
发表时间：
2021
影响因子：
13.6
通讯作者：
Zhou B.
中科院分区：
文献类型：
--
作者：
Zhang Y.;Ji Y.;Li J.;Bai J.;Chen S.;Li L.;Wang J.;Zhou T.;Jiang P.;Guan X.;Zhou B.
氨的有效脱除是废水处理中的一个难题，因为氨很容易转化为硝酸盐而不是N2。氯自由基（Clradical dot）氧化氨被认为是一种有效的方法。然而，由于羟基自由基的氧化能力过大，大量产生的有毒副产物氯酸盐和硝酸盐给其实际应用带来了很大的风险。在此，我们提出了一种在自驱动光电催化（PEC）系统中使用BiVO4/ wo3光阳极选择性产生Clradical dot的新方法。氯自由基dot1主要是通过修饰BiVO4来调节wo3的价带边缘，通过调节孔的中等氧化力来减少氯自由基dot1的生成，从而抑制氯酸盐和硝酸盐的生成。采用BiVO4/ wo3和Si光伏电池作为复合光阳极，提高了光吸收和电子空穴分离，从而增强了Clradical dot的产生，实现了自驱动氨降解。结果表明，在120 min内，10 mg L−1的氨氮去除率为99.3%，总氮去除率为80.1%。与WO3相比，氯酸盐和硝酸盐的毒性副产物分别被抑制79.3%和31%。本研究为开发高效、节能、环保的氨污染处理方法提供了新的思路。
The efficient removal of ammonia is a difficult issue in wastewater treatment because ammonia is easily converted to nitrate instead of N2. The oxidation of ammonia by chlorine radical (Clradical dot) is recognized as an effective method. However, the massive generation of toxic byproducts chlorate and nitrate pose great risk for its practical application due to the excessive oxidation capacity of hydroxyl radical. Herein, we propose a novel method to selectively generate Clradical dotfor efficient ammonia removal using BiVO4/WO3photoanode in a self-driven photoelectrocatalytic (PEC) system. Clradical dotwas predominantly produced by regulating the valence band edge of WO3though modifying BiVO4, which tuned the moderate oxidative force of hole to reduce OHradical dotgeneration and thereby inhibited the formation of chlorate and nitrate. The self-driven ammonia degradation was achieved by employing BiVO4/WO3and Si photovoltaic cells as composite photoanodes to improve light-absorption and electron-hole separation, thus enhancing Clradical dotproduction. These results showed that 10 mg L−1of ammonia-N was completely removed (99.3 %) in 120 min with 80.1 % of total nitrogen removal. Toxic byproducts chlorate and nitrate were inhibited by 79.3 % and 31 %, respectively, compared to WO3. This work provides new insights to develop efficient, energy-saving and environment-friendly method for ammonia pollution treatment.