-
过氧化氢(H2O2)作为一种安全性高、制备成本较低和绿色健康无污染的常用氧化剂[1],在一定触媒(如Fe2+)作用下可产生氧化性极强的活性自由基,能够高效氧化降解水中污染物,在工业废水治理和水体修复等方面扮演着重要角色[2-3]。次氯酸钠(NaClO)也是水处理过程中常用的清洁药剂,已被证明对废水具有独特的净化作用[4-5]。此外,H2O2可以和NaClO反应选择性生成氧化活性较强的单线态氧(1O2)(式(1))[6]。有研究表明,H2O2协同NaClO体系可以实现水中氰化物[7]、有机酚类[8]等污染物的高效去除。笔者科研团队前期的研究也证明H2O2协同NaClO体系可以有效产生1O2活性物种,实现典型有机磷污染物氨基三亚甲基膦酸的氧化去除[9]。
次磷酸盐(H2PO2−,P的价态为+1)是一种磷含氧酸盐,作为还原剂被广泛应用于化学镀镍等表面处理行业[10-11],因此,在相关生产中不可避免地会产生大量含有H2PO2−的工业废水,其中磷含量在几十~几百mg·L−1[12]。当水体中磷含量负荷过多时,会引起富营养化而破坏水生环境[13]。此外,磷污染也会导致人类神经中枢受损,严重时可造成致畸、致癌[14]。目前,H2PO2−废水处理方法有很多,例如吸附法[15]、生物法[16]、离子交换法[17]、氧化沉淀法[18]等。其中,氧化沉淀法对H2PO2−的去除以及磷回收效果显著,是处理废水中H2PO2−的常用方法。然而,H2PO2−与正磷酸盐(PO43−,P的价态为+5)相比溶解度较大,故H2PO2−的去除通常需先将其氧化成PO43−,再投加沉淀剂进而析出去除或回收[19]。LIU等[20]研究了高强短波紫外(UV)联合H2O2氧化H2PO2−的效果,证明该UV/H2O2体系生成的羟基(·OH)自由基可有效将H2PO2−氧化成PO43−。YLMÉN等[21]研究报道采用H2O2加热法将化工厂废水中的H2PO2−氧化为PO43−,然后通过添加MgCl2使PO43−沉淀生成磷酸铵镁。因此,基于H2O2氧化处理H2PO2−是可行的。
近年来,基于H2O2氧化的芬顿/类芬顿工艺由于其能产生强氧化性的活性物种·OH[22],已被应用于废水中H2PO2−的氧化去除。LIU等[23]采用紫外-芬顿法实现高效处理化学镀镍废水中的H2PO2−并证明了·OH的氧化主导作用。谢腾飞等[24]采用光芬顿法处理H2PO2−取得了良好效果。1O2作为一种典型非自由基活性物种,具有对水基质耐受性较好、卤化物消毒副产物产生较少、寿命相对较长(溶液中为10−6~10−3 s)等优势,已经成为水处理领域中氧化去除污染物的有利选择之一[25-26]。然而,利用1O2氧化处理废水中H2PO2−效果却尚不清楚。故本研究选取NaClO与H2O2联合体系产生1O2去处理废水中的H2PO2−。
本研究以H2PO2−为目标污染物,探究了H2O2/NaClO协同体系对H2PO2−氧化生成PO43−的效果和反应机制。通过向溶液中投加H2O2和NaClO,将废水中的H2PO2−有效氧化为PO43−,实现H2PO2−的氧化去除;采用自由基淬灭实验和电子顺磁共振法检测了体系中参与H2PO2−氧化的主要活性物种,探讨其催化氧化机制;此外,考察了H2O2浓度、NaClO浓度、初始溶液pH、共存无机阴离子(SO42−、NO3−、HCO3−、Cl−)、共存有机阴离子柠檬酸根(C6H5O73−)和腐殖酸(HA)对反应体系氧化H2PO2−为PO43−效率的影响;通过在酸性介质(pH<4.3)下将Fe3+添加到生成的PO43−废水中以形成FePO4沉淀物来验证后续化学沉淀工艺处理的可行性;最后,对含H2PO2−实际废水进行处理,表明了该体系的可行性。以期为含H2PO2−的工业废水处理提供参考。
H2O2/NaClO协同体系对废水中次磷酸盐的处理效果及氧化机制
Performance and oxidation mechanism of H2O2/NaClO synergistic system on hypophosphite treatment in wastewater
-
摘要: 本研究以废水中的次磷酸盐(H2PO2−)为目标污染物,比较了过氧化氢(H2O2)、次氯酸钠(NaClO)和H2O2/NaClO协同体系对H2PO2−的处理效果。结果表明,H2O2/NaClO协同体系的处理效果最优,能够实现有效氧化H2PO2−生成PO43−。利用自由基淬灭实验和电子自旋共振波谱(ESR)分析发现,该体系中ClO−、·OH、·O2−和1O2是体系氧化H2PO2−的活性物种,其中1O2起主要作用。详细探究了H2O2浓度、NaClO浓度、初始溶液pH、共存无机阴离子(SO42−、NO3−、HCO3−、Cl−)、共存有机阴离子柠檬酸根(C6H5O73−)和腐殖酸(HA)对反应体系氧化H2PO2−为PO43−效率的影响。当H2O2和NaClO投加量均为50 mmol·L−1,初始溶液pH为5,反应120 min时,1 mmol·L−1 H2PO2−氧化为PO43−的生成率为88%。该反应体系中SO42−、NO3−、HCO3−和Cl−对H2PO2−的氧化去除无明显影响,但C6H5O73−和HA的存在对H2PO2−的氧化去除有抑制作用。通过在酸性介质(pH<4.3)下将Fe3+添加到生成的PO43−废水中以形成FePO4沉淀物,实现磷在废水中去除同时回收磷。最后,验证了该体系对含H2PO2−实际废水处理的可行性。以上研究结果可以为含H2PO2−的工业废水处理提供参考。Abstract: In this study, hypophosphate (H2PO2−) in wastewater was selected as the target pollutant. The performance for H2PO2− oxidation to orthophosphate (PO43−) via varies methods including hydrogen peroxide (H2O2), sodium hypochlorite (NaClO) and H2O2/ NaClO synergistic system were compared. It was found that H2O2/ NaClO synergistic system had the best performance on the oxidation of H2PO2− to PO43−. The radical quenching experiments and electron spin resonance (ESR) spectroscopy results proved that ClO−, ·OH, ·O2− and 1O2 were contributable to the oxidation of H2PO2− to PO43− in the H2O2/NaClO synergistic system, and the key active species was 1O2. The effects of H2O2 concentration, NaClO concentration, initial solution pH, coexisting inorganic anions (SO42−, NO3−, HCO3− and Cl−), coexisting organic anions citrate (C6H5O73−) and humic acids (HA) on the oxidation efficiency of H2PO2− to PO43− by the H2O2/ NaClO synergistic system was investigated. The results indicated that the production of PO43− was 88% at 120 min when the initial concentration of H2PO2− was 1.0 mmol·L−1, the dosages of NaClO and H2O2 were 50 mmol·L−1, and the initial solution pH was 5. In this reaction system, SO42−, NO3−, HCO3− and Cl− caused hardly significant effect on the oxidation of H2PO2−, while C6H5O73−and HA concentration could have the inhibitory effects. Finally, phosphorus was recovered via forming FePO4 precipitates by adding Fe3+ to the generated PO43− wastewater in an acidic medium (pH < 4.3). Finally, the applicability of this system for treatment of actual wastewater containing H2PO2− was confirmed. This study can provide a reference for the treatment of industrial wastewater containing H2PO2−.
-
Key words:
- sodium hypochlorite /
- hydrogen peroxide /
- hypophosphite oxidation /
- orthophosphate /
- singlet oxygen
-
-
[1] 朱小康, 李梅, 杜甜甜, 等. 过氧化氢高级氧化技术研究进展[J]. 城镇供水, 2021, 06: 71-79. [2] 卓宏标, 刘建勇, 傅学丽, 等. 过氧化氢和过氧化硫酸钠复合物对高位池尾水的净化效果研究[J]. 安徽农业科学, 2022, 50: 81-84. [3] GHANBARI F, WANG Q, HASSANI A, et al. Electrochemical activation of peroxides for treatment of contaminated water with landfill leachate: Efficacy, toxicity and biodegradability evaluation[J]. Chemosphere, 2021, 279: 130610. doi: 10.1016/j.chemosphere.2021.130610 [4] DING N, LI Z W, JIANG L, et al. Kinetics and mechanisms of bacteria disinfection by performic acid in wastewater: In comparison with peracetic acid and sodium hypochlorite[J]. Science of the Total Environment, 2023, 878: 162606. doi: 10.1016/j.scitotenv.2023.162606 [5] JAVEED T, NAWAZ R, AL-HUSSAIN S A, et al. Application of advanced oxidation processes for the treatment of color and chemical oxygen demand of pulp and paper wastewater[J]. Water, 2023, 15: 1347. doi: 10.3390/w15071347 [6] LU X, ZHOU X, QIU W, et al. Singlet oxygen involved electrochemical disinfection by anodic oxidation of H2O2 in the presence of Cl−[J]. Chemical Engineering Journal, 2022, 446: 136871. doi: 10.1016/j.cej.2022.136871 [7] TEIXEIRA L A C, ARELLANO M T C, SARMIENTO C M, et al. Oxidation of cyanide in water by singlet oxygen generated by the reaction between hydrogen peroxide and hypochlorite[J]. Minerals Engineering, 2013, 50: 57-63. [8] ZONG Y, CHEN L, ZENG Y Q, et al. Do we appropriately detect and understand singlet oxygen possibly generated in advanced oxidation processes by electron paramagnetic resonance spectroscopy?[J]. Environmental Science & Technology, 2023, 57: 9394-9404. [9] 郭振杰, 刘雪瑜, 黎佳茜, 等. 次氯酸钠耦合过氧化氢法降解氨基三亚甲基膦酸研究[J]. 环境科学学报, 44 (2): 117-124. [10] SUDAGAR J, LIAN J, and SHA W. Electroless nickel, alloy, composite and nano coatings–A critical review[J]. Journal of Alloys and Compounds, 2013, 571: 183-204. doi: 10.1016/j.jallcom.2013.03.107 [11] LEI Y, SONG B N, VAN DER WEIJDEN R D, et al. Electrochemical induced calcium phosphate precipitation: importance of local pH[J]. Environmental Science & Technology, 2017, 51: 11156-64. [12] SHIH Y J, LIN C P, and HUANG Y H. Application of Fered-Fenton and chemical precipitation process for the treatment of electroless nickel plating wastewater[J]. Separation and Purification Technology, 2013, 104: 100-05. doi: 10.1016/j.seppur.2012.11.025 [13] WITHERS P J, ELSER J J, HILTON J, et al. Greening the global phosphorus cycle: how green chemistry can help achieve planetary P sustainability[J]. Green Chemistry, 2015, 17: 2087-99. doi: 10.1039/C4GC02445A [14] 李芳, 刘柏林. PFS和PAM化学沉淀法处理高磷废水的实验研究[J]. 广州化工, 2020, 48: 85-87. [15] SUN M M, SU J X, LIU S M, et al. Simultaneous removal of nickel and phosphorus from spent electroless nickel plating wastewater via calcined Mg-Al-CO3 hydroxides[J]. RSC Advances, 2015, 5: 80978-89. doi: 10.1039/C5RA12570G [16] 王凌云, 王小杰, 邵谦. 化学镀镍老化液的生物处理[J]. 电镀与涂饰, 2011, 30: 34-37. [17] PARKER K. Renewal of spent electroless nickel plating baths[J]. Plating and Surface Finishing, 1980, 67: 48-52. [18] 刘万民, 许稳, 杨宏健, 等. 次磷酸盐型化学镀镍废液处理研究进展[J]. 湖南工程学院学报(自然科学版), 2022, 32: 61-68. [19] GUAN W, SUN G G, YIN L, et al. Ti4O7/g-C3N4 visible light photocatalytic performance on hypophosphite oxidation: Effect of annealing temperature[J]. Frontiers in Chemistry, 2018, 6: 37. doi: 10.3389/fchem.2018.00037 [20] LIU P, LI C, LIANG X, et al. Advanced oxidation of hypophosphite and phosphite using a UV/H2O2 process[J]. Environmental Technology, 2013, 34: 2231-39. doi: 10.1080/09593330.2013.765917 [21] YLMéN R, GUSTAFSSON A M, CAMERANI-PINZANI C, et al. Recovery of phosphorous from industrial waste water by oxidation and precipitation[J]. Environmental Technology, 2018, 39: 1886-97. doi: 10.1080/09593330.2017.1342698 [22] LIU Y, and WANG J. Multivalent metal catalysts in Fenton/Fenton-like oxidation system: A critical review[J]. Chemical Engineering Journal, 2023: 143147. [23] LIU P, LI C, LIANG X, et al. Recovery of high purity ferric phosphate from a spent electroless nickel plating bath[J]. Green Chemistry, 2014, 16: 1217-24. doi: 10.1039/C3GC41779D [24] 谢腾飞, 李一兵, 张娟娟, 等. 光芬顿法处理次磷酸盐同步回收磷性能及参数研究[J]. 环境科学学报, 2023, 43: 89-95. [25] XIE L B, WANG P F, LI Y, et al. Pauling-type adsorption of O2 induced electrocatalytic singlet oxygen production on N-CuO for organic pollutants degradation[J]. Nature Communications, 2022, 13: 5560. doi: 10.1038/s41467-022-33149-4 [26] LUO R, LI M Q, WANG C H, et al. Singlet oxygen-dominated non-radical oxidation process for efficient degradation of bisphenol A under high salinity condition[J]. Water Research, 2019, 148: 416-24. doi: 10.1016/j.watres.2018.10.087 [27] 张娟娟, 刘蕴晗, 乔梦, 等. TiO2纳米管阳极光电催化氧化次磷酸盐同时阴极回收金属铜[J]. 环境工程学报, 2022, 16: 1145-53. [28] TERANISHI M, HOSHINO R, NAYA S I, et al. Gold-nanoparticle-loaded carbonate-modified titanium (IV) oxide surface: visible-light-driven formation of hydrogen peroxide from oxygen[J]. Angewandte Chemie International Edition, 2016, 128: 12965-69. [29] LIU Y, MAO R, HAO J, et al. Efficient oxidation of ammonium to nitrogen gas via accelerated ClO· generation at TiO2/Ru-IrO2 bifacial electrode in a UV-driven photoelectrochemical system[J]. Chemical Engineering Journal, 2023, 463: 142499. doi: 10.1016/j.cej.2023.142499 [30] YANG Z, QIAN J, YU A, et al. Singlet oxygen mediated iron-based Fenton-like catalysis under nanoconfinement[J]. Proceedings of the National Academy of Sciences, 2019, 116: 6659-64. doi: 10.1073/pnas.1819382116 [31] LI Y, XIE S, and YAO J. Singlet oxygen generation for selective oxidation of emerging pollutants in a flow-by electrochemical system based on natural air diffusion cathode[J]. Environmental Science and Pollution Research, 2023, 30: 17854-64. [32] 王克诚, 陈雪灵. 浓度对H2O2-ClO−法制备单线态氧影响的研究[J]. 唐山师范学院学报, 2005, 02: 28-30. [33] ZHANG J J, DJELLABI R, ZHAO S, et al. Recovery of phosphorus and metallic nickel along with HCl production from electroless nickel plating effluents: The key role of three-compartment photoelectrocatalytic cell system[J]. Journal of Hazardous Materials, 2020, 394: 122559. doi: 10.1016/j.jhazmat.2020.122559 [34] TEIXEIRA L A C, DE FARIA GARDINGO M, YOKOYAMA L, et al. Degradation of surfactant SLS in water by singlet oxygen generated by the reaction between hydrogen peroxide and hypochlorite[J]. Water Science and Technology:Water Supply, 2012, 12: 810-17. doi: 10.2166/ws.2012.057 [35] MIYAMOTO S, MARTINEZ G R, MARTINS A P B, et al. Direct evidence of singlet molecular oxygen [O2 (1Δg)] production in the reaction of linoleic acid hydroperoxide with peroxynitrite[J]. Journal of the American Chemical Society, 2003, 125: 4510-17. doi: 10.1021/ja029262m [36] XIE X D, HU Y A, and CHENG H F. Rapid degradation of p-arsanilic acid with simultaneous arsenic removal from aqueous solution using Fenton process[J]. Water Research, 2016, 89: 59-67. doi: 10.1016/j.watres.2015.11.037 [37] ZHANG J J, LI Y B, XIE T F, et al. Enhanced photoelectrocatalytic oxidation of hypophosphite and simultaneous recovery of metallic nickel via carbon aerogel cathode[J]. Journal of Hazardous Materials, 2023, 448: 130601. doi: 10.1016/j.jhazmat.2022.130601 [38] SHAO C R, CAO H Y, DUAN L J, et al. Electrochemical activation of peroxydisulfate by Ti/ATO electrode: Performance and mechanism[J]. Separation and Purification Technology, 2022, 289: 120800. doi: 10.1016/j.seppur.2022.120800 [39] LUTZE H V, KERLIN N, and SCHMIDT T C. Sulfate radical-based water treatment in presence of chloride: formation of chlorate, inter-conversion of sulfate radicals into hydroxyl radicals and influence of bicarbonate[J]. Water Research, 2015, 72: 349-60. doi: 10.1016/j.watres.2014.10.006 [40] YANG Y, JIANG J, LU X L, et al. Production of sulfate radical and hydroxyl radical by reaction of ozone with peroxymonosulfate: A novel advanced oxidation process[J]. Environmental Science & Technology, 2015, 49: 7330-39. [41] 贺框, 黄凯华, 胡小英, 等. 用尖晶石CoFe2O4磁性颗粒非均相芬顿氧化废水中的柠檬酸镍[J]. 电镀与涂饰, 2022, 41: 1552-57. [42] LI J, ZHU Q L, and XU Q. Pd nanoparticles supported on hierarchically porous carbons derived from assembled nanoparticles of a zeolitic imidazolate framework (ZIF-8) for methanol electrooxidation[J]. Chemical Communications, 2015, 51: 10827-30. doi: 10.1039/C5CC03008K [43] 王森林, 蓝心仁, 黄婷婷, 等. 化学沉积Ni-Mo-P合金及其性能[J]. 电化学, 2005, 02: 182-87. [44] LONG X, XIONG Z, HUANG R, et al. Sustainable Fe (III)/Fe (II) cycles triggered by co-catalyst of weak electrical current in Fe (III)/peroxymonosulfate system: Collaboration of radical and non-radical mechanisms[J]. Applied Catalysis B:Environmental, 2022, 317: 121716. doi: 10.1016/j.apcatb.2022.121716 [45] JING J N, WANG X C, and ZHOU M H. Electro-enhanced activation of peroxymonosulfate by a novel perovskite-Ti4O7 composite anode with ultra-high efficiency and low energy consumption: The generation and dominant role of singlet oxygen[J]. Water Research, 2023, 232: 119682. doi: 10.1016/j.watres.2023.119682 [46] SONG X, PAN Y, WU Q, et al. Phosphate removal from aqueous solutions by adsorption using ferric sludge[J]. Desalination, 2011, 280: 384-90. doi: 10.1016/j.desal.2011.07.028 [47] WANG M, YANG Y, and ZHANG Y. Synthesis of micro-nano hierarchical structured LiFePO4/C composite with both superior high-rate performance and high tap density[J]. Nanoscale, 2011, 3: 4434-39. doi: 10.1039/c1nr10950b