当前位置: X-MOL 学术J. Environ. Manag. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Degradation of sulfamethoxazole with persulfate using spent coffee grounds biochar as activator.
Journal of Environmental Management ( IF 8.7 ) Pub Date : 2020-07-05 , DOI: 10.1016/j.jenvman.2020.111022
Aspasia Lykoudi 1 , Zacharias Frontistis 2 , John Vakros 3 , Ioannis D Manariotis 4 , Dionissios Mantzavinos 3
Affiliation  

In the present study, biochar from spent coffee grounds was synthesized via pyrolysis at 850 °C for 1 h, characterized and employed as catalyst for the degradation of sulfamethoxazole (SMX) by persulfate activation. A variety of techniques, such as physisorption of N2, scanning electron microscopy, Fourier transform infrared spectroscopy, X–ray diffraction, thermogravimetric analysis, and potentiometric mass titration, were employed for biochar characterization. The biochar has a surface area of 492 m2/g, its point of zero charge is 6.9, while mineral deposits are limited.

SMX degradation experiments were performed mainly in ultrapure water (UPW) at persulfate concentrations between 100 and 1000 mg/L, biochar concentrations between 50 and 200 mg/L, SMX concentrations between 500 and 2000 μg/L and initial solution pH between 3 and 10. Real matrices, besides UPW, were also tested, namely bottled water (BW) and treated wastewater (WW), while synthetic solutions were prepared spiking UPW with bicarbonate, chloride, humic acid or alcohols. Almost complete removal of SMX can be achieved using 200 mg/L biochar and 1000 mg/L sodium persulfate (SPS) within 75 min. The presence of biochar is important for the degradation process, while the activity of the biochar increases linearly with SPS concentration. Degradation follows a pseudo–order kinetic model and the rate increases with increasing biochar concentration and decreasing SMX concentration. Although SMX adsorption onto the biochar surface is favored at acidic conditions, degradation proceeds equally fast regardless of the initial solution pH. Reactions in either real matrix are slower, resulting in 55% SMX removal in 60 min for WW. Bicarbonate causes severe inhibition as only 45% of SMX can be removed within 75 min in UPW. The addition of alcohol slightly inhibits degradation suggesting that the reaction pathway is either under electron transfer control or due to the generation of surface oxygen radicals with higher oxidation potential than the homogeneously produced radicals.



中文翻译:

使用废咖啡渣生物炭作为活化剂,用过硫酸盐降解磺胺甲恶唑。

在本研究中,通过在850°C下热解1 h来合成废咖啡渣中的生物炭,其特征在于用作过硫酸盐活化降解磺胺甲恶唑(SMX)的催化剂。生物炭表征采用了多种技术,例如N 2的物理吸附,扫描电子显微镜,傅立叶变换红外光谱,X射线衍射,热重分析和电位滴定法。生物炭的表面积为492 m 2 / g,零电荷点为6.9,而矿藏有限。

SMX降解实验主要在超纯水(UPW)中进行,过硫酸盐浓度在100至1000 mg / L之间,生物炭浓度在50至200 mg / L之间,SMX浓度在500至2000μg/ L之间,初始溶液的pH在3至10之间除了UPW外,还测试了真实的基质,即瓶装水(BW)和处理后的废水(WW),同时制备了将碳酸氢盐,氯化物,腐殖酸或酒精加到UPW中的合成溶液。在75分钟内使用200 mg / L的生物炭和1000 mg / L的过硫酸钠(SPS)几乎可以完全去除SMX。生物炭的存在对于降解过程很重要,而生物炭的活性随SPS浓度线性增加。降解遵循伪级动力学模型,并且速率随着生物炭浓度的增加和SMX浓度的降低而增加。尽管在酸性条件下SMX吸附在生物炭表面上是有利的,但降解过程的进行速度同等快,与初始溶液的pH无关。在任一真实基质中的反应均较慢,导致WW在60分钟内去除55%SMX。碳酸氢盐会导致严重的抑制作用,因为在UPW中,仅75%的SMX可以在75分钟内去除。醇的添加略微抑制了降解,表明反应路径是在电子转移控制之下,或者是由于生成了具有比均相产生的自由基更高的氧化电位的表面氧自由基。无论初始溶液的pH值如何,降解都会同样快地进行。在任一真实基质中的反应均较慢,导致WW在60分钟内去除55%SMX。碳酸氢盐会导致严重的抑制作用,因为在UPW中,仅75%的SMX可以在75分钟内去除。醇的添加略微抑制了降解,表明反应路径是在电子转移控制之下,或者是由于生成了具有比均相产生的自由基更高的氧化电位的表面氧自由基。无论初始溶液的pH值如何,降解都会同样快地进行。在任一真实基质中的反应均较慢,导致WW在60分钟内去除55%SMX。碳酸氢盐会导致严重的抑制作用,因为在UPW中,仅75%的SMX可以在75分钟内去除。醇的添加略微抑制了降解,表明反应路径是在电子转移控制之下,或者是由于生成了具有比均相产生的自由基更高的氧化电位的表面氧自由基。

更新日期:2020-07-05
down
wechat
bug