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纺织工业是我国传统的支柱产业,在织造过程中普遍使用的喷水织机虽然具有质量好、产量高和费用低等优点,但同时也存在着耗水量大(年用水量可达4.5×108 t)和碳组分排放量高(出水COD为200~600 mg·L−1,SS>100 mg·L−1)等环境问题[1],因而会对水体、土壤及生态系统等造成严重伤害[2-3]。横跨江、浙两省的太湖,尽管水资源十分丰沛,但随着近年来两地纺织工业的高速发展,纺织废水排放量及其水污染程度大幅提升,多次频繁暴发的蓝藻表明区域内的水污染治理形势依旧严峻[4-6]。
目前,工业上对织造废水常用的处理技术包括焚烧[7-8]、气浮[9]、混凝[10]、沉淀[11]、好氧和厌氧生物技术[12]等,同时为了达到国家不断严苛的废水排放新标准,膜分离[13-14]、高级氧化技术[15]等强化方法也被应用到织造废水的深度处理过程中。膜分离法由于膜组件需定期更换导致成本较高;传统芬顿氧化技术虽然对污染物的氧化能力强,但其pH=3的最佳工艺条件导致人们在处理进水和出水为pH=6~8的喷织机废水时,不但需要加入大量酸碱调节溶液pH[16],而且还产生大量铁泥二次污染物,增加了水处理的难度与成本[17-18]。
近年来,类芬顿催化氧化法因具有pH使用范围广、催化效率高、催化剂可回收等优点[19-20],已成为高级氧化技术中的研究热点。由于类芬顿反应不再局限于Fe2+与H2O2的组成和均相反应模式,因而在催化剂和氧化剂的组成和反应模式上有更多样性的选择。Cu、Mn、Co等过渡金属氧化物、氢氧化物及其复合物替代Fe2+, PMS、PDS和NaClO替代氧化剂H2O2等[21-24],它们在氧化反应中表现出的强氧化能力和高选择性以及宽pH反应条件,使类芬顿反应在难降解产物的完全去除中被寄予厚望。虽然已有较多类芬顿体系被用于含芳环类结构的难降解有机污染物的去除,但针对喷水织机废水中含有的丙烯酸及其酯这类有机小分子物质,由于它们具有分子结构简单、性质稳定、溶解度大、极性强等特征,并且还可能是经其他水处理方法后所产生的中间产物或最终产物等,因而它们的矿化去除与芳环类物质相比难度更大,有关其高效去除的成功范例也较少[25-27]。
本研究采用共沉淀法合成CuO@Fe3O4非均相类芬顿催化剂,通过构建CuO@Fe3O4/NaClO催化氧化体系,考察其对喷水织机废水中典型有机小分子污染物丙烯酸和丙烯酸甲酯的降解能力,讨论不同反应条件下的丙烯酸和丙烯酸甲酯矿化效果,探讨CuO@Fe3O4/NaClO体系的催化氧化机理,获得可溶性小分子有机污染物在污水深度处理过程中的特征行为和规律,旨在为水体中有机碳的总量控制和减排提供技术支撑。
CuO@Fe3O4催化NaClO 对水中丙烯酸及其酯的矿化去除
Mineralization and removal of acrylic acid and its esters from water by CuO@Fe3O4 catalyzed NaClO
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摘要: 为实现污水尾端处理中可溶性小分子有机物的完全去除,以克服因它们的大量存在使水体中总有机碳含量增加而引发的严重环境问题,采用氧化剂NaClO和双金属氧化物CuO@Fe3O4组成的催化氧化体系,对喷水织机废水中典型的极性小分子有机物丙烯酸和丙烯酸甲酯进行矿化去除研究;通过X射线衍射 (XRD) 、扫描电子显微镜 (SEM) 、X射线能谱 (EDS) 和BET分析等方法对催化剂进行结构表征和形貌观察,确定催化剂最佳合成方法,并通过氧化实验考察催化剂双金属组成、氧化剂NaClO浓度、催化剂加入量、溶液初始pH和循环催化氧化等因素对小分子有机污染物矿化去除的效果。结果表明:初始铁铜摩尔比为5∶1时,合成的5CuO@Fe3O4纳米粒子催化活性最高;当5CuO@Fe3O4和NaClO投加量分别为0.48 g·L−1、16 mmol·L−1、pH=8.3时,对0.2 g·L−1丙烯酸的COD去除率可达61%;催化剂经过7次循环操作后,对丙烯酸或丙烯酸甲酯仍能保持48%或45%的COD去除率;EPR实验证明·OH是催化氧化体系中降解丙烯酸和丙烯酸甲酯的主要活性物种。上述研究结果为揭示污染水体中难降解极性小分子有机物的矿化去除规律,实现水体中有机碳的总量控制和减排目标提供了技术支撑。Abstract: Small organic molecules are refractory components in sewage treatment. Their presence in large quantities can increase the total organic carbon content in water and cause serious environmental problems. In this study, the activation of NaClO by CuO@Fe3O4 was evaluated by modeling the mineralization of polar organic molecules acrylic acid and methyl acrylate in jet loom wastewater. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy spectroscopy (EDS) and Brunauer-Emmett-Teller (BET) were used to reveal the morphology and microstructure of CuO@Fe3O4, and determine the optimized synthesis method. The effects of bimetallic composition, NaClO concentration, amount of CuO@Fe3O4, initial pH and cyclic catalytic oxidation on the mineralization of acrylic acid and methyl acrylate were investigated. The results showed that 5CuO@Fe3O4 exhibited a strong catalytic activity in the mineralization process at the initial Fe-Cu molar ratio of 5:1. When the dosages of 5CuO@Fe3O4 and NaClO were 0.48 g·L−1 and 16 mmol·L-1 respectively, the removal rate of COD for 0.2 g·L−1 acrylic acid was 61% at pH =8.3. After seven cycles of operation, the removal rates of COD of acrylic acid and methyl acrylate acid were still 48% and 45%, respectively. EPR experiments showed that ·OH was the main active species for the degradation of acrylic acid and methyl acrylate in the catalytic oxidation system. These results provide a technical support for revealing the rule of mineralization and removal of refractory polar organic molecules in polluted water, so as to achieve the total amount control and emission reduction goal of organic carbon in water.
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Key words:
- mineralization /
- CuO@Fe3O4 /
- NaClO /
- acrylic acid /
- methyl acrylate
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[1] 马慧婕, 沈忱思, 章耀鹏, 等. 纺织工业产排污特征与水污染治理技术进展[J]. 环境科学研究, 2020, 33(11): 2529-2539. doi: 10.13198/j.issn.1001-6929.2020.10.02 [2] 周谨. 无机陶瓷膜在印染废水处理中的应用[J]. 膜科学与技术, 2010, 30(3): 116-119. doi: 10.3969/j.issn.1007-8924.2010.03.023 [3] 陈凤兰, 徐志荣. 《纺织染整工业水污染物排放标准》实施评估: 以浙江省为例[J]. 环境保护与循环经济, 2019, 39(12): 72-78. [4] 陆茸, 翟康, 徐圃青. 重大环境政策对常州印染行业发展的影响[J]. 江苏科技信息, 2021, 38(22): 72-76. doi: 10.3969/j.issn.1004-7530.2021.22.018 [5] 何锡君, 孙英军, 王贝, 等. 浙江省出入太湖河道水量水质及污染物通量变化(2007—2019年)[J]. 湖泊科学, 2021, 33(5): 1425-1435. doi: 10.18307/2021.0527 [6] 翟康, 李嘉义, 袁逸, 等. 常州市太湖流域水生态环境功能区水污染源排放情况分析[J]. 科技创新与生产力, 2021(3): 41-45. doi: 10.3969/j.issn.1674-9146.2021.03.041 [7] 宋凯. 丙烯酸装置废水焚烧处理控制方案浅析[J]. 石油化工自动化, 2011, 47(2): 33-35. doi: 10.3969/j.issn.1007-7324.2011.02.008 [8] 王瑞, 李圣强, 赵云海. 高浓度丙烯酸废水处理试验研究[J]. 山东工业技术, 2014(12): 40. [9] 朱又春, 罗爱武, 林美强, 等. 磁分离法处理含油废水研究[J]. 广东工业大学学报, 1998, 15(2): 15-20. [10] BENER S, BULCA Ö, PALAS B, et al. Electrocoagulation process for the treatment of real textile wastewater: Effect of operative conditions on the organic carbon removal and kinetic study[J]. Process Safety and Environmental Protection, 2019, 129: 47-54. doi: 10.1016/j.psep.2019.06.010 [11] 姚佳伟, 杨庆峰, 陆盛森, 等. 磁性纳米颗粒催化NaClO降解有机废水研究[J]. 工业水处理, 2020, 40(10): 39-43. [12] 庞浩然, 李旭东, 欧文韬, 等. 曝气生物滤池对喷水织机废水BOD5去除效果的研究[J]. 上海交通大学学报(农业科学版), 2009, 27(5): 516-519. [13] 何晨曦, 房浩亮, 古丽加衣娜尔·巴合提, 等. 印染废水处理研究进展[J]. 轻纺工业与技术, 2021, 50(8): 130-131. doi: 10.3969/j.issn.2095-0101.2021.08.059 [14] 王双, 张倩, 王薇, 等. 反渗透双膜工艺处理印染废水研究进展[J]. 能源环境保护, 2019, 33(3): 1-4. doi: 10.3969/j.issn.1006-8759.2019.03.001 [15] SUKANYA DEVI R, DHURAI B, SUNDARESAN S, et al. Advanced oxidation processes (AOP) : Effective innovative treatment methods to degrade textile dye effluent[M]//MUTHU S S. Advances in Textile Waste Water Treatments. Springer Press, 2021: 173-203. [16] XING M, XU W, DONG C, et al. Metal sulfides as excellent co-catalysts for H2O2 decomposition in advanced oxidation processes[J]. Chemistry, 2018, 4(6): 1359-1372. doi: 10.1016/j.chempr.2018.03.002 [17] KREMER M L. The Fenton reaction: Dependence of the rate on pH[J]. The Journal of Physical Chemistry A, 2003, 107(11): 1734-1741. doi: 10.1021/jp020654p [18] JAIN B, SINGH A K, KIM H, et al. Treatment of organic pollutants by homogeneous and heterogeneous Fenton reaction processes[J]. Environmental Chemistry Letters, 2018, 16(3): 947-967. doi: 10.1007/s10311-018-0738-3 [19] SCARIA J, GOPINATH A, NIDHEESH P. A versatile strategy to eliminate emerging contaminants from the aqueous environment: Heterogeneous Fenton process[J]. Journal of Cleaner Production, 2021, 278: 124014. doi: 10.1016/j.jclepro.2020.124014 [20] MA D, YI H, LAI C, et al. Critical review of advanced oxidation processes in organic wastewater treatment[J]. Chemosphere, 2021, 275: 130104. doi: 10.1016/j.chemosphere.2021.130104 [21] FU W, YI J, CHENG M, et al. When bimetallic oxides and their complexes meet Fenton-like process[J]. Journal of Hazardous Materials, 2021, 424: 127419. [22] XIE Z H, ZHOU H Y, HE C S, et al. Synthesis, application and catalytic performance of layered double hydroxide based catalysts in advanced oxidation processes for wastewater decontamination: A review[J]. Chemical Engineering Journal, 2021, 414: 128713. doi: 10.1016/j.cej.2021.128713 [23] JIA L, JUN S, KUN F, et al. Heterogeneous catalytic persulfate oxidation of organic pollutants in the aquatic environment: Nonradical mechanism[J]. Progress in Chemistry, 2021, 33(8): 1311-1322. [24] LUO H, ZENG Y, HE D, et al. Application of iron-based materials in heterogeneous advanced oxidation processes for wastewater treatment: A review[J]. Chemical Engineering Journal, 2021, 407: 127191. doi: 10.1016/j.cej.2020.127191 [25] 刘玥, 赵来群, 龚为进, 等. 硅酸锌铁催化臭氧氧化水体中的丙烯酸[J]. 化工时刊, 2020, 34(3): 16-20. doi: 10.16597/j.cnki.issn.1002-154x.2020.03.005 [26] 高超, 乐清华, 冯杰. Fenton氧化法降解丙烯酸废水的研究[J]. 环境工程学报, 2009, 3(7): 1279-1283. [27] 姜晓锋, 高明瑜, 王诗涵, 等. 多相催化氧化-EGSB组合工艺处理丙烯酸废水研究[J]. 工业水处理, 2021, 41(2): 92-96. [28] 何余生, 李忠, 奚红霞, 等. 气固吸附等温线的研究进展[J]. 离子交换与吸附, 2004, 20(4): 376-384. doi: 10.3321/j.issn:1001-5493.2004.04.012 [29] FANG J, FU Y, SHANG C. The roles of reactive species in micropollutant degradation in the UV/free chlorine system[J]. Environmental Science & Technology, 2014, 48(3): 1859-1868. [30] 李博强. UV-LED/NaClO高级氧化工艺对典型PPCPs类污染物的降解[D]. 杭州: 浙江工业大学, 2020. [31] PIZZOLATO T, CARISSIMI E, MACHADO E, et al. Colour removal with NaClO of dye wastewater from an agate-processing plant in Rio Grande do Sul, Brazil[J]. International Journal of Mineral Processing, 2002, 65(3/4): 203-211. [32] 徐文英, 高浩阳. NiOx(OH)y/NaClO催化氧化体系对模拟印染废水中活性艳红K-2BP的降解脱色效果[J]. 环境工程学报, 2021, 15(3): 835-846. doi: 10.12030/j.cjee.202006141 [33] PUANGPETCH T, SOMMAKETTARIN P, CHAVADEJ S, et al. Hydrogen production from water splitting over eosin Y-sensitized mesoporous-assembled perovskite titanate nanocrystal photocatalysts under visible light irradiation[J]. International Journal of Hydrogen Energy, 2010, 35(22): 12428-12442. doi: 10.1016/j.ijhydene.2010.08.138 [34] CAO F, ZHANG M T, YUAN S J, et al. Transformation of acetaminophen during water chlorination treatment: Kinetics and transformation products identification[J]. Environmental Science and Pollution Research, 2016, 23(12): 12303-12311. doi: 10.1007/s11356-016-6341-x [35] LEI Y, CHEN C S, TU Y J, et al. Heterogeneous Degradation of organic pollutants by persulfate activated by CuO-Fe3O4: mechanism, stability, and effects of pH and bicarbonate ions[J]. Environmental Science & Technology, 2015, 49(11): 6838-6845. [36] LI L, ABE Y, KANAGAWA K, et al. Distinguishing the 5, 5-dimethyl-1-pyrroline N-oxide (DMPO)-OH radical quenching effect from the hydroxyl radical scavenging effect in the ESR spin-trapping method[J]. Analytica Chimica Acta, 2004, 512(1): 121-124. doi: 10.1016/j.aca.2004.02.020 [37] ZHOU X Q, JAWAD A, LUO M Y, et al. Regulating activation pathway of Cu/persulfate through the incorporation of unreducible metal oxides: Pivotal role of surface oxygen vacancies[J]. Applied Catalysis B:Environmental, 2021, 286: 119914. doi: 10.1016/j.apcatb.2021.119914 [38] 彭伟, 方振东, 李晨旭, 等. 单组分过渡金属氧化物及其复合材料催化Oxone去除4-氯酚的效能对比研究[J]. 当代化工, 2019, 48(5): 890-894. doi: 10.3969/j.issn.1671-0460.2019.05.003 [39] PENG W, LIU J, LI C X, et al. A multipath peroxymonosulfate activation process over supported by magnetic CuO-Fe3O4 nanoparticles for efficient degradation of 4-chlorophenol[J]. Korean Journal of Chemical Engineering, 2018, 35(8): 1662-1672. doi: 10.1007/s11814-018-0074-0 [40] SUN M Y, LEI Y, CHENG H, et al. Mg doped CuO-Fe2O3 composites activated by persulfate as highly active heterogeneous catalysts for the degradation of organic pollutants[J]. Journal of Alloys and Compounds, 2020, 825: 154036. doi: 10.1016/j.jallcom.2020.154036 [41] 李锋超. 纳米钴锌氧化物活化过硫酸盐(PMS)降解有机污染物研究[D]. 重庆: 重庆大学, 2020. [42] 李章良, 张国鑫, 潘文斌. Cu/Zn非均相Fenton催化剂的制备及其对环丙沙星的降解效果[J]. 环境工程学报, 2021, 15(3): 806-816. doi: 10.12030/j.cjee.202006148