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海上船舶运输业已成为全球化趋势下的主要运载方式。船舶,特别是原油运输船在航运过程中会产生大量的含油废水,包括舱底水、压载水以及机械清洗时产生的洗舱水等[1]。此类含油废水成分复杂多样,具有含盐量高、有机物浓度高、水质水量变化大等特点[2]。船舶含油废水是一种典型的难去除废水,传统的处理工艺均具有一定的局限性。如物理分离法无法完全分离含油污水中的乳化油[3],此类废水的可生化性较差导致生物法的适应性较差[4],电化学法则需要消耗大量的能量,运行成本高[3]。因此,亟需开发便捷高效的船舶含油废水处理工艺。
动态膜技术是一种利用在过滤初期形成的相对致密的滤饼层对污染物截留的膜分离过程。其在高效去除污染物的同时,又具有设备简单、清洗方便、能耗低等优点,近年来在多种含油废水处理工艺中得到推广与应用[5-7]。如利用动态膜过程处理炼油废水、油污海水或水包油乳液,对浊度的去除率均可达98%以上[7-9]。动态膜技术作为一项高效率、低成本的水处理工艺,有望在船舶含油废水深度处理中发挥重要作用。活性炭是一种孔隙结构丰富、比表面积大的优良吸附剂,已被广泛应用于水处理领域。活性炭预涂动态膜,作为一种高效、低成本的动态膜具有一定的实际应用前景[10-13]。
溶解性有机物(dissolved organic matter,DOM)作为船舶含油废水中的主要污染物组分,其成分十分复杂,且不同组分之间可能存在相互作用,是影响工艺处理效率的一个重要原因。目前常采用溶解性有机碳(DOC)、化学需氧量(COD)和特定波长254 nm处的吸光度(UV254)等来表征DOM的组成[14-15]。然而这些指标在提供DOM成分等方面的信息能力有限。近年来,随着超高分辨质谱技术的发展,静电场轨道阱质谱(Orbitrap MS)和傅里叶变换离子回旋共振质谱(FT-ICR MS)被广泛用来获得复杂组分中溶解性有机物的分子组成信息[16-18],有助于从更深的层面揭示DOM组成特征对处理工艺效率的影响。
基于此,本研究对活性炭预涂动态膜过程对船舶含油废水不同组分的分离过程和机制进行剖析。在对含油废水总体成分评估的基础上,采用超高分辨质谱Orbitrap MS深入分析活性炭预涂动态膜过程处理前后船舶含油废水中DOM的分子组成特征,通过识别处理过程中去除部分、透过部分和截留部分DOM的分子组成差异,揭示不同操作时间时动态膜反应器处理船舶含油废水中DOM的去除规律,以期为船舶含油废水动态膜处理工艺的高效运行提供参考。
活性炭预涂动态膜处理船舶含油废水过程中溶解性有机物的分子组成特征
Molecular composition characteristics of dissolved organic compounds in the process of treatment of marine oily wastewater by activated carbon precoated dynamic membrane
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摘要: 动态膜技术以其高效、低成本等优点,在船舶含油废水深度处理领域展现出重要的应用潜力。然而船舶含油废水中有机物组成极其复杂,其在动态膜处理过程中的分子特征及变化尚需进一步研究。采用超高分辨质谱研究船舶含油废水中溶解性有机物(DOM)在动态膜过滤过程处理不同时间的分子组成特征。结果表明,船舶含油废水经动态膜处理前有超过2 200 种DOM分子式,其主要由CHOS、CHONP等含杂原子类物质组成。动态膜处理过程中,前10 min由于活性炭的较强的吸附能力,对大部分有机物显示出良好的去除率,废水的COD和DOC去除率均在80%以上,此阶段对大分子质量、不饱和氧化性DOM去除效果较好。随后活性炭吸附能力下降,动态膜对COD和DOC的去除率逐渐衰减,60 min时均下降至50%左右。60 min后船舶含油废水中DOM的分子组成未观察到明显变化。本研究揭示了船舶含油废水在动态膜处理过程中DOM分子层面的组成和变化特征,为动态膜技术高效处理难去除船舶含油废水提供一定的工艺参考。Abstract: Dynamic membrane technology has the advantages of high efficiency and low cost in the field of advanced treatment of marine oily wastewater. However, the composition of organic matter in marine oily wastewater is extremely complex, and further study is necessary for the molecular characteristics and changes in the dynamic membrane treatment process. In this study, ultra-high-resolution mass spectrometry was used to investigate the changes in the molecular composition characteristics of dissolved organic matter (DOM) in marine oily wastewater during dynamic membrane filtration treatment. The results showed that there were more than 2 200 DOM molecular formulas in raw marine oily wastewater, which were mainly composed of heteroatomic-containing substances such as CHOS and CHONP. Due to the significant adsorption capacity of activated carbon, an excellent removal rate occurred for most organic matter in the first 10 minutes of the dynamic membrane treatment process. The removal rates of COD and DOC in wastewater were both greater than 80%, and high molecular weight and unsaturated oxidizing DOM was effectively removed at this stage. Subsequently, the adsorption capacity of activated carbon decreased, and the removal rates of COD and DOC by the dynamic membrane gradually declined, both dropping to around 50% after 60 minutes, moreover no significant changes occurred in the molecular composition of DOM in the marine oily wastewater. This study revealed the molecular composition and variation characteristics of DOM in the process of dynamic membrane treatment of marine oily wastewater, and could provide a certain process reference for the efficient treatment of refractory marine oily wastewater by dynamic membrane technology.
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表 1 船舶含油废水前端处理工艺出水水质参数
Table 1. Effluent water quality parameters of the front-end treatment process of marine oily wastewater
出水参数 COD/(mg·L−1) 含油率 SS/(mg·L−1) TS/(mg·L−1) 隔油沉淀分离池 ≤2 500 ≤1% 气浮一体化装置 ≤1 500 ≤10 mg·L−1 ≤50 ≤30 生化池 ≤500 生物膜反应器 ≤200 表 2 船舶含油废水水质参数
Table 2. Characteristics of marine oily wastewater
处理
时间/minpH Cl−/
(mg·L−1)NO2−-N/
(mg·L−1)NO3−-N/
(mg·L−1)SO4−/
(mg·L−1)NH3-N/
(mg·L−1)COD/
(mg·L−1)DOC/
(mg·L−1)UV254 0 (8.29±0.03) (3 314.25±211.05) (0.37±0.02) (8.19±0.17) (1 053.09±21.19) (1.95±0.10) (165.41±8.59) (207.72±3.13) (1.92±0.16) 10 (8.32±0.05) (2 869.75±125.58) (0.02±0.02) (7.84±0.08) (1 281.96±128.13) (0.41±0.02) (26.14±2.34) (33.27±3.00) (0.54±0.08) 30 (8.27±0.08) (2 140.74±103.97) (0.05±0.00) (7.34±0.29) (1 191.74±96.03) (0.86±0.03) (53.24±4.80) (62.81±4.80) (0.82±0.05) 60 (8.34±0.04) (3 242.96±129.67) (0.17±0.01) (8.02±0.52) (1 232.17±28.56) (1.34±0.11) (84.13±0.96) (99.34±8.88) (1.19±0.06) 120 (8.38±0.06) (3 056.25±269.38) (0.29±0.01) (7.69±0.36) (1 024.42±2.38) (1.59±0.05) (120.79±7.34) (151.63±14.07) (1.54±0.04) 180 (8.28±0.07) (2 970.43±215.59) (0.34±0.02) (8.23±0.12) (1 209.35±88.12) (1.78±0.08) (142.28±3.80) (178.17±14.70) (1.64±0.04) -
[1] 尹晓峰, 马艳玲, 金玉涛. 船舶废水处理技术综述[J]. 舰船科学技术, 2010, 32(12): 30-33. [2] 边婷婷, 李阳, 王储, 等. 船舶含油废水电化学氧化预处理研究[J]. 工业水处理, 2020, 40(10): 103-106. [3] 代洪亮, 古李娜, 赵芷晴, 等. 船舶油污水处理技术研究与应用进展[J]. 江苏科技大学学报(自然科学版), 2022, 36(3): 99-108. [4] 龚帆, 刘霞, 顾人吉. 一种组合工艺的船舶油污水处理技术[J]. 上海船舶运输科学研究所学报, 2019, 42(3): 80-84. [5] YANG T, MA Z F, YANG Q Y. Formation and performance of Kaolin/MnO2 bi-layer composite dynamic membrane for oily wastewater treatment: Effect of solution conditions[J]. Desalination, 2011, 270(1): 50-56. [6] ZHAO Y, TAN Y, WONG F S, et al. Formation of dynamic membranes for oily water separation by crossflow filtration[J]. Separation and Purification Technology, 2005, 44(3): 212-220. doi: 10.1016/j.seppur.2005.01.010 [7] YANG T, QIAO B, LI G C, et al. Improving performance of dynamic membrane assisted by electrocoagulation for treatment of oily wastewater: Effect of electrolytic conditions[J]. Desalination, 2015, 363: 134-143. doi: 10.1016/j.desal.2015.01.010 [8] SHAO S, LIU Y, SHI D, et al. Control of organic and surfactant fouling using dynamic membranes in the separation of oil-in-water emulsions[J]. Journal of Colloid and Interface Science, 2020, 560: 787-794. doi: 10.1016/j.jcis.2019.11.013 [9] ZHANG Y, ZHAO H. Formation of phosphorylated ZrxSi1−xO2/Al2O3 self-assembled membrane for cleaning oily seawater[J]. Journal of Membrane Science, 2017, 536: 28-36. doi: 10.1016/j.memsci.2017.04.061 [10] 王文华, 赵瑾, 马宇辉, 等. 预涂动态膜强化超滤去除海水中有机物及其对膜污染的影响[J]. 环境科学学报, 2017, 37(4): 1349-1357. [11] 赵瑾, 王文华, 曹军瑞, 等. 预涂动态膜对超滤膜处理海水中有机物的影响[J]. 工业水处理, 2019, 39(3): 67-70. doi: 10.11894/1005-829x.2019.39(3).067 [12] WU S E, HWANG K J, CHENG T W, et al. Dynamic membranes of powder-activated carbon for removing microbes and organic matter from seawater[J]. Journal of Membrane Science, 2017, 541: 189-197. doi: 10.1016/j.memsci.2017.07.006 [13] ANANTHARAMAN A, CHUN Y, HUA T, et al. Pre-deposited dynamic membrane filtration – A review[J]. Water Research, 2020, 173: 115558. doi: 10.1016/j.watres.2020.115558 [14] ZHANG B, SHAN C, HAO Z, et al. Transformation of dissolved organic matter during full-scale treatment of integrated chemical wastewater: Molecular composition correlated with spectral indexes and acute toxicity[J]. Water Research, 2019, 157: 472-482. doi: 10.1016/j.watres.2019.04.002 [15] MENG F, HUANG G, YANG X, et al. Identifying the sources and fate of anthropogenically impacted dissolved organic matter (DOM) in urbanized rivers[J]. Water Research, 2013, 47(14): 5027-5039. doi: 10.1016/j.watres.2013.05.043 [16] WANG Y, LI N, FU Q, et al. Conversion and impact of dissolved organic matters in a heterogeneous catalytic peroxymonosulfate system for pollutant degradation[J]. Water Research, 2023, 241: 120166. doi: 10.1016/j.watres.2023.120166 [17] 陈炜鸣, 辜哲培, 何晨, 等. 垃圾渗滤液浓缩液中溶解性有机物在热活化过硫酸盐体系的转化特性[J]. 环境科学学报, 2023, 43(8): 122-130. [18] PHUNGSAI P, KURISU F, KASUGA I, et al. Molecular characterization of low molecular weight dissolved organic matter in water reclamation processes using Orbitrap mass spectrometry[J]. Water Research, 2016, 100: 526-536. doi: 10.1016/j.watres.2016.05.047 [19] 胡权. 动态膜中试系统的集成及其成膜材料的制备与特性研究[D]. 广州: 广东工业大学, 2021. [20] 戴丽. 活性炭预涂动态膜处理船舶生活污水[D]. 哈尔滨: 哈尔滨工程大学, 2018. [21] DITTMAR T, KOCH B, HERTKORN N, et al. A simple and efficient method for the solid-phase extraction of dissolved organic matter (SPE-DOM) from seawater[J]. Limnology and Oceanography-Methods, 2008, 6: 230-235. doi: 10.4319/lom.2008.6.230 [22] YANG Y, WANG P, SHI S, et al. Microwave enhanced Fenton-like process for the treatment of high concentration pharmaceutical wastewater[J]. Journal of Hazardous Materials, 2009, 168(1): 238-245. doi: 10.1016/j.jhazmat.2009.02.038 [23] 魏朝成, 于彩虹, 徐磊. 粉末活性炭预沉积强化超滤膜处理微污染水的效应研究[J]. 矿业科学学报, 2020, 5(4): 458-466. [24] 李健. 活性炭投加对厌氧动态膜生物反应器的性能强化和机理研究[D]. 济南: 山东大学, 2020. [25] 王琳, 王宝贞, 王欣泽, 等. 活性炭与超滤组合工艺深度处理饮用水[J]. 中国给水排水, 2002(2): 1-4. [26] WANG H, CHENG Z, SUN Z, et al. Molecular insight into variations of dissolved organic matters in leachates along China’s largest A/O-MBR-NF process to improve the removal efficiency[J]. Chemosphere, 2020, 243: 125354. doi: 10.1016/j.chemosphere.2019.125354 [27] 田蕴, 郑天凌, 王新红. 厦门西港表层海水中多环芳烃(PAHs)的含量、组成及来源[J]. 环境科学学报, 2004(1): 50-55. [28] GU Z, BAO M, HE C, et al. Transformation of dissolved organic matter in landfill leachate during a membrane bioreactor treatment[J]. Science of The Total Environment, 2023, 856: 159066. doi: 10.1016/j.scitotenv.2022.159066 [29] XIANG Y, WANG H, SU L, et al. Molecular transformation and composition flow of dissolved organic matter in four typical concentrated leachates from the multi-stage membrane system[J]. Journal of Environmental Management, 2022, 310: 114759. doi: 10.1016/j.jenvman.2022.114759 [30] YUAN Z, HE C, SHI Q, et al. Molecular insights into the transformation of dissolved organic matter in landfill leachate concentrate during biodegradation and coagulation processes using ESI FT-ICR MS[J]. Environmental Science & Technology, 2017, 51(14): 8110-8118. [31] AL ZAROONI M, ELSHORBAGY W. Characterization and assessment of Al Ruwais refinery wastewater[J]. Journal of Hazardous Materials, 2006, 136(3): 398-405. doi: 10.1016/j.jhazmat.2005.09.060 [32] LIN J, LIAO Q, HU Y, et al. Effects of process parameters on sulfur migration and H2S generation during supercritical water gasification of sludge[J]. Journal of Hazardous Materials, 2021, 403: 123678. doi: 10.1016/j.jhazmat.2020.123678 [33] 郭送军, 韦进毅, 王晨路, 等. 基于FT-ICR MS的蒸汽爆破预处理强化污泥厌氧消化的有机物分子解析[J]. 环境工程学报, 2023, 17(4): 1337-1345. [34] BAHUREKSA W, TFAILY M M, BOITEAU R M, et al. Soil organic matter characterization by fourier transform ion cyclotron resonance mass spectrometry (FTICR MS): A critical review of sample preparation, analysis, and data interpretation[J]. Environmental Science & Technology, 2021, 55(14): 9637-9656. [35] WU S, YOU F, BOUGHTON B, et al. Chemodiversity of dissolved organic matter and its molecular changes driven by rhizosphere activities in Fe ore tailings undergoing eco-engineered pedogenesis[J]. Environmental Science & Technology, 2021, 55(19): 13045-13060. [36] 李利杰. 天然水体可溶有机质分子组成与分子结构分析方法与应用[D]. 北京: 中国石油大学(北京), 2019. [37] CORTÉS-FRANCISCO N, CAIXACH J. Fragmentation studies for the structural characterization of marine dissolved organic matter[J]. Analytical and Bioanalytical Chemistry, 2015, 407(9): 2455-2462. doi: 10.1007/s00216-015-8499-3 [38] LIU Z F, SLEIGHTER R L, ZHONG J Y, et al. The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry[J]. Estuarine Coastal and Shelf Science, 2011, 92(2): 205-216. doi: 10.1016/j.ecss.2010.12.030 [39] SHAKERI YEKTA S, GONSIOR M, SCHMITT-KOPPLIN P, et al. Characterization of dissolved organic matter in full scale continuous stirred tank biogas reactors using ultrahigh resolution mass spectrometry: A qualitative overview[J]. Environmental Science & Technology, 2012, 46(22): 12711-12719. [40] VARANASI L, COSCARELLI E, KHAKSARI M, et al. Transformations of dissolved organic matter induced by UV photolysis, hydroxyl radicals, chlorine radicals, and sulfate radicals in aqueous-phase UV-based advanced oxidation processes[J]. Water Research, 2018, 135: 22-30. doi: 10.1016/j.watres.2018.02.015