-
污水再生利用是解决水资源短缺的有效途径,微量污染物在污水处理厂出水中频繁检出,威胁再生水用水安全,需要研发高效的深度处理工艺将其去除[1-2]。常用的深度去除技术主要有生物处理、吸附、膜分离、高级氧化等。其中,吸附和膜分离技术只是对微量污染物进行了相转移,通常需要与高级氧化技术结合以实现污染物降解[3-4]。臭氧催化氧化作为常用的高级氧化技术,通过在反应体系中加入催化剂促进臭氧分解,引发自由基链式反应,具有氧化能力强,反应速率快,适用范围广,去除污染物彻底的特点,但也存在催化剂团聚、回收困难的问题[5-7]。
将臭氧催化氧化与陶瓷膜技术结合,构建的陶瓷催化膜-臭氧工艺,弥补了上述方法的不足,在复杂水体微量污染物处理中有广阔的应用前景。GUO等[8]的研究表明,2-羟基-4-甲氧基二苯甲酮(benzophenone-3, BP-3)的初始质量浓度为0.5 mg·L−1时,陶瓷膜-臭氧工艺对BP-3的去除率约为75%,CuMn2O4改性的陶瓷催化膜-臭氧工艺对BP-3的去除率提高至90%。LEE等[9]的研究表明,在双酚A(bisphenol,BPA)、苯并三唑(benzotriazole,BTA)、氯贝酸(clofibric acid,CA)的初始质量浓度为3 mg·L−1时,与陶瓷膜-臭氧工艺相比,CeOx改性的陶瓷催化膜-臭氧工艺对BPA的去除率由20%增至80%,对BTA去除率由50%增至57%,对CA的去除率由30%增至40%。PARK等[10]的研究表明,在对氯苯甲酸(p-chlorbenzoic acid, p-CBA)的初始质量浓度为5 mg·L−1时,与陶瓷膜-臭氧工艺相比,Fe2O3改性的陶瓷催化膜-臭氧工艺对p-CBA的去除率由28%增至46%。上述关于陶瓷催化膜-臭氧工艺去除微量污染物的研究中,实验进水均为以纯水为背景的自配水,对实际应用的参考价值有限。实际二级出水成分复杂,微量污染物与水中的有机物竞争催化臭氧氧化产生的活性氧物种,需要进一步研究陶瓷催化膜-臭氧工艺处理实际污水中微量污染物的特性。
在催化剂的选择方面,BYUN等[11]比较了铁氧化物、锰氧化物负载的陶瓷催化膜对富营养化湖泊中的有机物的去除效果,发现与铁氧化物相比,锰氧化物负载的陶瓷催化膜对TOC的去除率更高。与锰氧化物相比,锰基双金属氧化物由于双金属氧化物的存在,具有更高的催化性能[12-14]。因此,有必要进一步研究锰基双金属氧化物MnMeOx(Me=Fe、Co、Ce)改性陶瓷催化膜的性能。
本课题组前期研究[15]成功制备了4种基于α-MnO2的锰系陶瓷催化膜,包括单独α-MnO2 的催化膜和基于α-MnO2的MnMe双金属氧化物(Me=Fe、Co、Ce)的陶瓷催化膜(Mn-CM、MnFe-CM、MnCo-CM、MnCe-CM),表征了陶瓷催化膜的物相结构,构建了陶瓷催化膜-臭氧反应器,研究了其在批式运行条件下对阿特拉津的去除特性,与陶瓷膜相比,基于α-MnO2的Mn-CM催化臭氧氧化对阿特拉津的去除率提高了21.15%。与MnCM和MnMe-CM相比,MnCe-CM对阿特拉津的反应速率常数最大(1.62 min−1),去除率最高(99.99%),催化性能最优。进一步的机理分析表明,锰铈催化膜中丰富的微米反应器在臭氧催化氧化微量污染物中的重要作用,首先,电镜结果表明基于抽吸-原位氧化沉淀法制备的锰铈催化膜表面和孔内均存在明显的催化剂沉积;其次,锰铈催化膜-臭氧工艺对阿特拉津的总去除率为79%,其中,膜孔内的催化臭氧反应对阿特拉津的去除率为61%,膜孔催化与过滤对污染物去除的贡献率为77%;根据XPS表征、EPR表征和分子探针实验,MnCe-CM的2组氧化还原对(Ce3+/Ce4+和Mn3+/Mn4+)为锰铈催化膜催化氧化提供更多的氧空位,促进臭氧分解产生大量•OH(9.82 μmol·L−1)和•O2−(1.3 μmol·L−1),自由基氧化是锰铈催化膜催化臭氧氧化微量污染物的主要途径。
本研究基于课题组的前期成果,建立了锰铈催化膜-臭氧工艺(O3/MnCe-CM),并开展了连续运行实验,评估了其在不同臭氧投加量下对实际二级出水中4种典型微量污染物的去除特性,确定了最佳臭氧投加量,并分析了锰铈催化膜-臭氧工艺对实际二级出水中常规污染物的去除特性,目的是为锰铈催化膜-臭氧工艺的实际应用提供参考。
锰铈催化膜-臭氧工艺对污水厂二级出水的去除特性
The removal characteristics of pollutants in the secondary effluent by a MnCe-catalytic ceramic membrane-ozonation process
-
摘要: 为深入解析锰铈催化膜-臭氧工艺(O3/MnCe-CM)对二级出水中微量污染物和常规污染物的去除特性,以陶瓷膜-臭氧工艺(O3/CM)为对照,研究了锰铈催化膜-臭氧工艺在单独膜过滤、臭氧投加量2.5~5 mg·L−1时,对二级出水中4种典型微量污染物和常规有机物的去除特性。结果表明,与陶瓷膜-臭氧工艺相比,锰铈催化膜-臭氧工艺对阿特拉津、苯并三唑、避蚊胺和西玛津的去除率显著提高,臭氧投加量5 mg·L−1时,锰铈催化膜-臭氧工艺反应动力学常数为陶瓷膜-臭氧工艺的1.7~3倍。锰铈催化膜-臭氧工艺在二级出水体系中最佳臭氧投加量为5 mg·L−1,此时工艺对微量污染物的去除率均大于80%,满足国家生态环境部《水回用指南 再生水中药品和个人护理品类微量污染物处理技术》(T/CSES 42-2021)关于微量污染物去除的标准。锰铈催化膜-臭氧工艺对二级出水中TOC的去除率为32%,对UV254的去除率为66%,去除的有机物主要是腐殖酸类荧光物质,出水无急性毒性。Abstract: To comprehensively reveal the removal characteristics of micro-pollutants and conventional pollutants in the secondary effluent by the MnCe-catalytic ceramic membrane-ozonation (O3/MnCe-CM) process, the removal performance of O3/MnCe-CM process for four typical micro-pollutants and conventional pollutants was studied at the ozone dosages from 2.5 to 5 mg·L−1 with O3/CM as the control group. Moreover, the removal performance of membrane filtration for MnCe-CM was investigated with CM as the control group. The results show that the removal rates of atrazine, benzotriazole, DEET, and simazine by the O3/MnCe-CM process were significantly improved in comparison to O3/CM process. The kinetic constants of the O3/MnCe-CM process were 1.7-3 times those of the O3/CM process at the ozone dosage of 5 mg·L−1. The optimal ozone dosage of the O3/MnCe-CM process in the secondary effluent system was 5 mg·L−1, the average removal performance of four micropollutants was higher than 80% under this condition, which could meet the standard of 《Guidelines for water reuse—Treatment technologies for pharmaceuticals and personal care products in reclaimed water》(T/CSES 42-2021) of the Ministry of Ecology and Environment. In addition, the removal rates of the O3/MnCe-CM process for TOC and UV254 in the secondary effluent were 32% and 66%, respectively. The removed organic was mainly fluorescent humic acid substances, and no acute toxicity was detected in the effluent of the O3/MnCe-CM process.
-
Key words:
- catalytic ceramic membrane /
- catalytic ozonation /
- membrane fouling /
- secondary effluent
-
表 1 不同臭氧投加量下锰铈催化膜-臭氧工艺和陶瓷膜-臭氧工艺对微量污染物的反应动力学常数
Table 1. The reaction kinetic constants of the O3/CM and O3/MnCe-CM process
臭氧投加量/
(mg·L−1)工艺 反应动力学常数/min−1 阿特拉津 苯并三唑 避蚊胺 西玛津 2.5 陶瓷膜-臭氧 0.002 0.002 0.005 0.005 锰铈催化膜-臭氧 0.002 0.002 0.006 0.004 5 陶瓷膜-臭氧 0.003 0.008 0.009 0.005 锰铈催化膜-臭氧 0.006 0.016 0.016 0.015 -
[1] 王文龙,吴乾元,杜烨,等. 城市污水中新兴微量有机污染物控制目标与再生处理技术[J]. 环境科学研究, 2021, 34(7): 1672-1678. doi: 10.13198/j.issn.1001-6929.2020.09.15 [2] 胡洪营. 聚焦矛盾 精准施策 全面提升污水资源化利用水平[J]. 给水排水, 2021, 57(2): 1-3. [3] 宫飞蓬,李杨,霍健. 超滤+臭氧工艺对再生水厂的应用[J]. 膜科学与技术, 2011, 31(5): 52-57. doi: 10.3969/j.issn.1007-8924.2011.05.010 [4] 张凯. 臭氧/陶瓷膜-活性炭耦合工艺处理再生水协同效能研究[D]. 北京: 清华大学, 2020. [5] MANSAS C,MENDRET J,BROSILLON S,et al. Coupling catalytic ozonation and membrane separation:A review[J]. Separation and Purification Technology, 2020, 236: 116211-116230. [6] PSALTOU S,ZOUBOULIS A. Catalytic ozonation and membrane contactors-a review concerning fouling occurrence and pollutant removal[J]. Water, 2020, 12(11): 2964-2951. doi: 10.3390/w12112964 [7] PRAKASH N,SETHI M. A review of innovative bond instruments for sustainable development in Asia[J]. International Journal of Innovation Science, 2022, 14(3/4): 630-647. doi: 10.1108/IJIS-10-2020-0213 [8] GUO Y,SONG Z,XU B,et al. A novel catalytic ceramic membrane fabricated with CuMn2O4 particles for emerging UV absorbers degradation from aqueous and membrane fouling elimination[J]. Journal of Hazardous Materials, 2018, 344: 1229-1239. doi: 10.1016/j.jhazmat.2017.11.044 [9] LEE W J,BAO Y,HU X,et al. Hybrid catalytic ozonation-membrane filtration process with CeOx and MnOx impregnated catalytic ceramic membranes for micropollutants degradation[J]. Chemical Engineering Journal, 2019, 378: 121670-121682. doi: 10.1016/j.cej.2019.05.031 [10] PARK H,KIM Y,AN B,et al. Characterization of natural organic matter treated by iron oxide nanoparticle incorporated ceramic membrane-ozonation process[J]. Water Research, 2012, 46(18): 5861-5870. doi: 10.1016/j.watres.2012.07.039 [11] BYUN S,DAVIES S H,Alpatova A L,et al. Mn oxide coated catalytic membranes for a hybrid ozonation–membrane filtration:Comparison of Ti,Fe and Mn oxide coated membranes for water quality[J]. Water Research, 2011, 45(1): 163-170. doi: 10.1016/j.watres.2010.08.031 [12] ZHANG J,GUO Q,WU W,et al. Preparation of Fe-MnOX/AC by high gravity method for heterogeneous catalytic ozonation of phenolic wastewater[J]. Chemical Engineering Science, 2022, 255: 117667-117672. doi: 10.1016/j.ces.2022.117667 [13] WANG T,DE W M,DE G J. CoFe2O4-peroxymonosulfate based catalytic UF and NF polymeric membranes for naproxen removal:The role of residence time[J]. Journal of Membrane Science, 2022, 646: 120209-120219. doi: 10.1016/j.memsci.2021.120209 [14] YAN P,CHEN Z,WANG S,et al. Catalytic ozonation of iohexol with α-Fe0.9Mn0.1OOH in water:Efficiency,degradation mechanism and toxicity evaluation[J]. Journal of Hazardous Materials, 2021, 402: 123574-123586. doi: 10.1016/j.jhazmat.2020.123574 [15] HE Y,WANG L,CHEN Z,et al. Novel catalytic ceramic membranes anchored with MnMe oxide and their catalytic ozonation performance towards atrazine degradation[J]. Journal of Membrane Science, 2022, 648: 120362-120375. doi: 10.1016/j.memsci.2022.120362 [16] COSTANZO S D,WATKINSON A J,MURBY E J,et al. Is there a risk associated with the insect repellent DEET (N,N-diethyl-m-toluamide) commonly found in aquatic environments?[J]. Science of the Total Environment, 2007, 384(1-3): 214-220. doi: 10.1016/j.scitotenv.2007.05.036 [17] GAO X,WANG X,LI J,et al. Aquatic life criteria derivation and ecological risk assessment of DEET in China[J]. Ecotoxicology and Environmental Safety, 2020, 188: 109881-109888. doi: 10.1016/j.ecoenv.2019.109881 [18] PILLARD D A,CORNELL J S,DUFRESNE D L,et al. Toxicity of benzotriazole and benzotriazole derivatives to three aquatic species[J]. Water Research, 2001, 35(2): 557-560. doi: 10.1016/S0043-1354(00)00268-2 [19] CHOI Y,LEE J H,KIM K,et al. Identification,quantification,and prioritization of new emerging pollutants in domestic and industrial effluents,Korea:Application of LC-HRMS based suspect and non-target screening[J]. Journal of Hazardous Materials, 2021, 402: 123706-123718. doi: 10.1016/j.jhazmat.2020.123706 [20] TIAN Z,WANG B,LIANG Y,et al. Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater:utilizing low-density static magnetic field[J]. Frontiers of Environmental Science & Engineering, 2021, 15(5): 81-89. [21] YU H,ANUMOL T,PARK M,et al. On-line sensor monitoring for chemical contaminant attenuation during UV/H2O2 advanced oxidation process[J]. Water Research, 2015, 81: 250-260. doi: 10.1016/j.watres.2015.05.064 [22] CHEN H,PENG C,WANG L,et al. Mechanically tough,healable hydrogels synergistically reinforced by UV-responsive crosslinker and metal coordination interaction for wound healing application[J]. Chemical Engineering Journal, 2021, 403: 126341-126351. doi: 10.1016/j.cej.2020.126341 [23] LI C,SUN W,LU Z,et al. Systematic evaluation of TiO2-GO-modified ceramic membranes for water treatment:Retention properties and fouling mechanisms[J]. Chemical Engineering Journal, 2019, 378: 122138-122150. doi: 10.1016/j.cej.2019.122138 [24] WANG Y,CHEN L,CAO H,et al. Role of oxygen vacancies and Mn sites in hierarchical Mn2O3/LaMnO3-delta perovskite composites for aqueous organic pollutants decontamination[J]. Applied Catalysis B:Environmental, 2019, 245: 546-554. doi: 10.1016/j.apcatb.2019.01.025 [25] MAILLER R,GASPERI J,COQUET Y,et al. Study of a large scale powdered activated carbon pilot:Removals of a wide range of emerging and priority micropollutants from wastewater treatment plant effluents[J]. Water Research, 2015, 72: 315-330. doi: 10.1016/j.watres.2014.10.047 [26] 中国环境科学学会. 水回用指南 再生水中药品和个人护理品类微量污染物处理技术[M]. 北京: 中国环境科学学会, 2021. [27] AGENCY U S E P. Drinking Water Standards and Health Advisories; EPA 822-F-18–001[M]. Office of Water. Washington, DC, USA, USEPA, 2018. [28] 李先华. 己内酰胺废水色度来源分析及臭氧脱色研究[D]. 上海: 华东理工大学, 2014. [29] 张云辉,陆杰,李海宁,等. 臭氧工艺在废水脱色中的应用[J]. 水处理技术, 2012, 38(11): 3-6. doi: 10.16796/j.cnki.1000-3770.2012.11.027