不同氯酚催化氧化降解反应动力学
Catalytic oxidation kinetics of different chlorinated phenols
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摘要: 通过共沉淀法制备了Fe-Cu-柱撑黏土（Fe-Cu-PILC）催化剂，并以单氯酚、二氯酚、三氯酚作为模式化合物，研究了氯酚中氯原子取代数目、取代位置对其降解动力学的影响，并探讨了氯离子的存在对反应的影响，也基于费米分布函数对其降解动力学进行非线性拟合.结果显示，这种基于费米函数的半经验模型适用于模拟氯酚氧化降解动力学反应（R2>0.818）.氯酚降解速率如下：3-氯酚（3-CP）> 3，5-二氯酚（3，5-DCP）> 2，3-二氯酚（2，3-DCP）> 3，4-二氯酚（3，4-DCP）> 2，5-二氯酚（2，5-DCP）> 4-氯酚（4-CP）> 2-氯酚（2-CP）> 2，4-二氯酚（2，4-DCP）> 2，4，6-三氯酚（2，4，6-TCP）>2，6-二氯酚（2，6-DCP）.氯酚降解过程明显受到苯环氯原子取代数目、取代位置的影响，且氯原子取代位置具有更重要的影响：氯原子取代数目相同时，间位氯越多，降解越快，邻、对位越多，降解越慢.这主要通过影响表观速率常数k和半衰期t*得以实现.3，5-DCP降解表观速率常数k高达18.17 h-1，半衰期为0.2 h，而2，6-DCP表观速率常数仅为0.64 h-1，半衰期为5.88 h.氯离子的存在对氯酚降解动力学过程产生不同程度的抑制作用，其中2，6-DCP、2，4，6-TCP的抑制作用最为明显，这主要是由于氯离子的存在延长了其半衰期（分别由5.88 h、4.29 h延长至9.00 h、5.99 h），而对3，4-DCP、3，5-DCP则几乎没有抑制作用.表明氯离子抑制邻位氯代程度高的氯酚降解而不抑制间位氯代程度高的氯酚降解.研究结果为深入揭示氯酚降解机理提供了理论基础，也为提高含酚废水降解速率提供了技术参考.Abstract: Fe-Cu-pillared clay (Fe-Cu-PILC) catalyst was prepared by co-precipitation method. The effect of the substitution position and number of chlorine atoms and chloride ions on the degradation kinetics of chlorophenols (CPs) was studied using monochlorophenols, dichlorophenols and richlorophenol as the reaction mode compounds, Fe-Cu-PILC as the Fenton-like catalyst. The degradation kinetics was nonlinearly fitted based on the Fermi's equation. The results showed that a semi-empirical kinetic model based on Fermi's equation could be used to describe the oxidation process of CPs (R2>0.818). CPs degradation rate followed the order of 3-chlorophenol (3-CP)>3,5-dichlorophenol (3,5-DCP)>2,3-dichlorophenol (2,3-DCP)>3,4-dichlorophenol (3,4-DCP)>2,5-dichlorophenol (2,5-DCP)>4-chlorophenol (4-CP)>2-chlorophenol (2-CP)>2,4-dichlorophenol (2,4-DCP)>2,4,6-trichlorophenol (2,4,6-TCP)>2,6-dichlorophenol (2,6-DCP). The substitution position and number of chlorine atoms had strong effect on its degradation. The substitution position showed greater impact. For chlorophenols with the same number of chlorine atoms,the more meta-chloro substitution it had, the faster the oxidation was. On the contrary, the more ortho-chloro and para-chloro substitution it had, the slower the oxidation was. This was ascribed to the effect on the apparent rate constant (k) and half-life (t*). The apparent rate constant and half-life of 3,5-DCP and 2,6-DCP were 18.17 h-1 and 0.64 h-1, and 0.2 h and 5.88 h, respectively. In addition, in the presence of chloride ions, the degradation of 2,6-DCP and 2,4,6-TCP was strongly inhibited, in which their t* was extended from 5.88 h to 9.0 h and from 4.29 h to 5.99 h, respectively. But the degradation of 3,4-DCP and 3,5-DCP was not inhibited. This suggested that chloride ions inhibited the oxidation of the chlorophenols with more ortho-chloro substitution, but had no effect on the oxidation of the chlorophenols with more meta-chloro substitution. This study provided valuable information to assist in revealing the catalytic oxidation mechanism of chlorophenols, and improving the treatment efficiency of phenol-containing wastewater using catalytic wet peroxide oxidation (CWPO) technologies.
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[1] CZAPLICKA M. Sources and transformations of chlorophenols in the natural environment[J]. Science of the Total Environment, 2004, 322(1/3): 21-39. [2] HAGLUND P. Methods for treating soils contaminated with polychlorinated dibenzo-p-dioxins, dibenzofurans, and other polychlorinated aromatic compounds[J]. Ambio, 2007, 36(6): 467-474. [3] 马承愚, 彭英利. 高浓度难降解有机废水的治理与控制(第二版)[M]. 北京: 化学工业出版社, 2010: 35-42. MA C Y, PENG Y L. Treatment and control of high concentration refractory organic wastewater (Second edition)[M]. Beijing: Chemical Industry Press, 2010:35 -42 (in Chinese).
[4] OLLER I, MALATO S, SANCHEZ-PEREZ J A. Combination of advanced oxidation processes and biological treatments for wastewater decontamination-A review[J]. Science of the Total Environment, 2011, 409(20): 4141-4166. [5] 王彦丽. 多氯酚污染物的降解研究进展[J]. 安徽农业科学, 2009, 37(30): 14858-14861. WANG Y L. Research progress on degradation of the chlorinated phenols on organic pollutants[J]. Journal of Anhui Agricultural Sciences, 2009, 37(30):14858-14861 (in Chinese).
[6] 程丽华, 黄君礼, 高会旺. Fenton试剂降解水中酚类物质的研究[J]. 重庆环境科学, 2003, 25(10): 35-42. CHENG L H, HUANG J L, GAO H W. Study on treatment of phenolic compounds by Fenton's reagent[J]. Chongqing Environmental Sciences, 2003,25(10):35-42 (in Chinese).
[7] PERATHONER S, CENTI G. Wet hydrogen peroxide catalytic oxidation (WHPCO) of organic waste in agro-food and industrial streams[J]. Topics in Catalysis, 2005, 33(1/4): 207-224. [8] 吴金华, 于少明, 章璟嵩, 等. CWPO中催化剂的应用研究现状及趋势[J]. 污染防治技术, 2007, 20(3): 46-50. WU J H, YU S M, ZHANG J S, et al. Advances in research on the catalysts in CWPO process[J]. Pollution Control Technology,2007, 20(3): 46-50 (in Chinese).
[9] 郭茂峰, 于少明, 杨杰茹, 等. 铜铁复合层柱黏土的制备及其在含酚废水处理中的应用[J]. 工业催化, 2007, 15(7): 56-61. GUO M F, YU S M, YANG J R, et al. Synthesis of Cu/Fe-PILC and its application in phenolic wastewater treatment[J]. Industrial Catalysis, 2007, 15(7):56-61 (in Chinese).
[10] 王维明, 张冉, 王树涛, 等. 非均相光Fenton降解4-氯酚的研究[J]. 安全与环境学报, 2013, 13(1):31-35. WANG W M, ZHANG R, WANG S T, et al. Degradation efficiency of 4-chlorophenol via heterogeneous photo-Fenton[J]. Journal of Safety and Environment, 2013, 13(1):31-35 (in Chinese).
[11] 曹明礼, 袁继祖, 余永富, 等. 柱撑黏土的制备与表征[J]. 武汉理工大学学报, 2002, 24(5):19-21. CAO M L, YUAN J Z, YU Y F, et al. Preparation and characterization of clays pillared by polyhydroxyl-Al cations[J]. Journal of Wuhan University of Technology, 2002, 24(5):19-21 (in Chinese).
[12] 吴平霄, 张惠芬, 肖文丁, 等. 河南信阳蒙脱石柱化研究Ⅰ.多核金属阳离子结构合成[J]. 矿物岩石地球化学通报, 1997, 16(S1): 69-70. WU P X, ZHANG H F, XIAO W D, et al. Study on the monoclimation of montmorillonite from Xinyang of Henan province Ⅰ. Synthesis of polynuclear metal cationic structure[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 1997, 16(S1):69-70 (in Chinese).
[13] 赵东源, 杨亚书, 郭燮贤, 等. 铁铝复合柱撑黏土的制备、酸性与表征(Ⅱ)[J]. 物理化学学报, 1993, 9(3): 336-344. ZHAO D Y, YANG Y S, GUO X X, et al. Preparation, characterization and surface acidity of hydroxy-Fe-Al pillared clays containing mixed metal complexes(Ⅱ) [J]. Chinese Journal of Physical Chemistry, 1993, 9(3):336-344 (in Chinese).
[14] KHANKHASAEVA S T, BADMAEVA S V, DASHINAMZHILOVA E T. Preparation, characterization and catalytic application of Fe-and Fe/Al-pillared clays in the catalytic wet peroxide oxidation of 4-chlorophenol[J]. Studies in Surface Science and Catalysis. 2008, 174(2): 1311-1314. [15] 童东绅, 夏厚胜, 周春晖. 蒙皂族黏土基催化材料的设计制备和催化作用[J]. 催化学报, 2009, 30(11): 1170-1187. TONG D S,XIA H S,ZHOU X H.Design, preparation and catalysis of montmorillonite clay-based catalysts[J]. Chinese Journal of Catalysis, 2009, 30(11):1170-1187 (in Chinese).
[16] ZHOU S W, QIAN Z Y, SUN T, et al. Catalytic wet peroxide oxidation of phenol over Cu-Ni-Al hydrotalcite[J]. Applied Clay Science. 2011, 53(4): 627-633. [17] 徐睿, 周世伟, 张华, 等. 铁铜-柱撑黏土催化过氧化氢氧化降解4-氯酚研究[J]. 工业水处理, 2015, 35(4):20-24. XU R, ZHOU S W, ZHANG H, et al. Research on Fe-Cu pillard clay for catalyzing 4-chlorophenol oxidation degradation[J]. Industrial Water Treatment, 2015,35(4):20-24 (in Chinese).
[18] 赵玲, 彭平安. 二氧化锰氧化降解五氯酚的动力学模拟研究[J]. 环境科学, 2008, 29(4): 972-977. ZHAO L, PENG P A. Oxidation kinetics of pentachlorophenol by manganese dioxide[J]. Environmental Science, 2008, 29(4):972-977 (in Chinese).
[19] 孙振世, 杨晔, 陈英旭, 等. 纳米TiO2薄膜光催化降解2,4-二氯酚的动力学研究[J]. 环境科学学报, 2003, 23(6): 716-720. SUN Z S, YANG Y, CHEN Y X, et al. Photocatalytic degradation kinetics of 2,4-dichlorophenol on nanostructured TiO2 film[J]. Environmental Science, 2003,23(6):716-720 (in Chinese).
[20] GORDON T R, MARSH A L. Temperature dependence of the oxidation of 2-chlorophenol by hydrogen peroxide in the presence of goethite[J]. Catalysis Letters, 2009, 132(3/4): 349-354. [21] RAMIREZ J H, SILVA M T, VICENTE M A, et al. Degradation of acid orange 7 using a saponite-based catalyst in wet hydrogen peroxide oxidation: Kinetic study with the Fermi's equation[J]. Applied Catalysis B-Environmental, 2011, 101(3/4): 197-205. [22] PARK J W, DEC J, KIM J E, et al. Dehalogenation of xenobiotics as a consequence of binding to humic materials [J]. Archives of Environmental Contamination and Toxicology, 2000, 38(4): 405-410. [23] GUO J. Catalytic wet oxidation over pillared clay catalyst in packed-bed reactors: Experiments and modeling [D]. Saint Louis, Washington University, 2005. [24] MEI J G, YU S M, CHENG J. Heterogeneous catalytic wet peroxide oxidation of phenol over delaminated Fe-Ti-PILC employing microwave irradiation[J]. Catalysis Communications, 2004, 5(8): 437-440. [25] 王兆慧, 马万红, 陈春城, 等. TiO2光催化降解氯酚类有机污染物的反应机理[J]. 中国科学: 化学, 2011, 41(8): 1286-1297. WANG Z H, MA W H, CHEN C C, et al. Photodegradation mechanism of chlorophenols pollutants by TiO2 photocatalysis[J]. Chinese Science: Chemistry, 2011, 41(8):1286-1297 (in Chinese).
[26] ZHANG J, LI G B, MA J. Effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate[J]. Journal of Environmental Sciences, 2003, 15(3): 342-345. [27] ZHOU S W, GU C T, QIAN Z Y, et al. The activity and selectivity of catalytic peroxide oxidation of chlorophenols over Cu-Al hydrotalcite/clay composite[J]. Journal of Colloid and Interface Science, 2011, 357(2): 447-452. [28] ANTONARAKI S, ANDROULAKI E, DIMOTIKALI D, et al. Photolytic degradation of all chlorophenols with polyoxometallates and H2O2[J]. Journal of Photochemistry Photobiology A-Chemistry, 2002, 148(1/3): 191-197. [29] 高乃云, 祝淑敏, 马艳, 等. 2,4,6-三氯酚的UV/H2O2
光化学降解[J]. 中南大学学报(自然科学版), 2013, 44(3): 1262-1268. GAO N Y, ZHU S M, MA Y, et al. UV/H202 photochemical degradation of 2,4,6-trichlorophenol[J]. Journal of Central South University(Science and Technology), 2013, 44(3):1262-1268 (in Chinese).[30] LIN Z R, ZHAO L, DONG Y H. Quantitative characterization of hydroxyl radical generation in a goethite-catalyzed Fenton-like reaction[J]. Chemosphere, 2015, 141(5): 7-12. [31] 胡学锋, 吴蕾, 骆永明. 苯胺在含富里酸/Fe(Ⅲ)高盐水体中的光氯化[J]. 环境化学, 2014, 33(4): 611-616. HU X F, WU L, LUO Y M. Photochlorination of aniline in Fe(Ⅲ)/fulvic acid-containing saline water under simulated solar light irradiation[J]. Environmental Chemistry, 2014, 33(4): 611-616 (in Chinese).
[32] JI H H, CHANG F, HU X F, et al. Photo catalytic degradation of 2,4,6-trichlorophenol over g-C3N4 under visible light irradiation[J]. Chemical Engineering Journal, 2013, 218: 183-190. -
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