Journal of Textile Research ›› 2025, Vol. 46 ›› Issue (09): 197-204.doi: 10.13475/j.fzxb.20250200101

• Dyeing and Finishing Engineering • Previous Articles     Next Articles

Optimization of treatment efficiency of indigo dyeing wastewater by electrocoagulation using Al-Mg alloy anodes

ZUO Zhuofan1,2,3, LU Kailiang1,2,3, LI Qianwen1,2,3, ZHANG Wei1,2,3()   

  1. 1. College of Textile and Garment, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, China
    2. Key Laboratory of Electrochemical Technology Application in Textile Industry, Shijiazhuang, Hebei 050018, China
    3. Hebei Technology Innovation Center for Textile and Garment, Shijiazhuang, Hebei 050018, China
  • Received:2025-02-05 Revised:2025-06-25 Online:2025-09-15 Published:2025-11-12
  • Contact: ZHANG Wei E-mail:weizhang2999@163.com

Abstract:

Objective The passivation of Al anodes during electroflocculation reduces the dissolution rate and current efficiency, negatively impacting flocculation yield, contaminant removal efficiency, and increasing energy consumption. In order to solve the above problems, Al-Mg alloy electrodes with varying Mg content were selected as anodes, and the electroflocculation system for indigo dyeing wastewater was constructed together with graphite cathode. The wastewater treatment efficiency of Al-Mg alloy anode and the Mg doping on the inhibition of anode passivation were investigated to understand the activation mechanism of Al-Mg alloy electrode by Mg element, providing a new path and theoretical basis for the performance and effect optimization of the electroflocculation system for indigo dyeing wastewater.

Method Al and four types of Al-Mg alloy electrodes with different Mg contents, namely 5052 (Mg 2.2%-2.8%), 5A03 (Mg 3.2%-3.8%), 5083 (Mg 4.0%-4.9%), 5A06 (Mg 5.8%-6.8%), were selected as anode. The performance of alloy electrode on chemical oxygen demand (COD), total organic carbon (TOC) removal and energy consumption was analyzed. The influence of Mg doping on the dissolution and passivation of the alloy anode during the electroflocculation process was investigated with EDS energy spectroscopy, thermal infrared imaging, open circuit potential and polarisation curve tests.

Results Under the same electroflocculation operating parameters i.e.,applied voltage of 10 V, electrolytic time of 20 min and plate space of 3 cm, the electroflocculation treatment results showed that Al-Mg alloy 5A03 and 5083 did not have significant performance on COD removal rate, chromaticity and flocculation yield. Therefore, Al, 5052 and 5A06 were selected for the experimental verification and characterization analysis of Mg doping, which is conducive to improving electrode activity and electroflocculation effect. Within the same operational conditions, the loss rate of the Al-Mg 5052 was lower than that of Al and 5A06. After electroflocculation with 5A06 and 5052 anodes, the TOC removal rate was 49% and 48%, respectively, and the chromaticity was 50 times for both cases, which were both better than pure Al. In addition, the COD removal rate with 5A06 anode was higher than the electroflocculation system of pure Al anode. After the electroflocculation process, the corrosion potentials for Al, 5052, and 5A06 electrodes shifted positively. The polarization curves of the Al electrode showed current plateau due to the inhibition of metal ion dissolution by passivation. However, it was not detected in that of Al-Mg alloy electrodes. Following treatment, the Al anode surface showed a decrease in Al content and an increase in O content, alongside the presence of Al2O3 spherical particles in the electrode's dissolved pits, with Al2O3 content exceeding that of the Al-Mg alloy surface.

Conclusion The wastewater after electroflocculation using Al-Mg alloy 5A06 and 5052 achieved effectively improved TOC removal rate and chromaticity compared to the pure Al anode electroflocculation system. Notably, the COD removal efficiency with the 5A06 anode exceeded that of pure Al. The polarization curve of the Al-Mg alloys electrode after electrocoagulation showed no current plateau, and the open-circuit potential was negatively shifted. The performance is attributed to the addition of Mg, which increases the electrode dissolution rate and inhibits passivation. Thermal infrared imaging revealed more pronounced passivation at the electrode plate edges compared to the center, with the passivation area of the Al electrode being significantly greater than that of the Al-Mg alloy electrode. In conclusion, the electroflocculation system constructed with 5A06 as the anode improved the treatment effect of indigo dyeing wastewater to a certain extent and effectively inhibited the passivation process of the electrode.

Key words: electrocoagulation, indigo dyeing wastewater, wastewater treatment, alumium-magesium alloy electrode, flocculation efficiency, electrode activation, electrode passivation, polarization curve

CLC Number: 

  • X791

Tab.1

Influence of electrolysis time on wastewater treatment offect after electroflocculation with Al electrode"

电解
时间/min
电极
损耗率/%
COD
去除率/%
色度 絮凝
物质量/g
15 0.873 64.80 70 0.105 0
20 1.261 67.14 60 0.239 6
25 1.503 69.18 60 0.290 0
30 1.693 71.42 60 0.343 4

Tab.2

Effect of Al and Al-Mg electrodes on indigo wastewater treatment"

电极
材料
COD
去除
率/%
色度 COD去除比能耗/
(kW·h·
(g COD)-1)
絮凝
物质量/g
电极
损耗率/%
Al 72.56 60 0.012 7 0.186 1 1.025
5052 70.27 50 0.013 5 0.285 4 0.778
5A03 69.69 60 0.013 9 0.209 7 1.370
5083 69.92 60 0.014 2 0.198 5 1.095
5A06 74.67 50 0.013 6 0.237 0 1.460

Fig.1

Surface morphologies of electrodes. (a) Before electrocoagulation; (b) After electrocoagulation"

Fig.2

SEM images of flocs formed by different electrode systems. (a) Al electrode; (b) 5052 electrode; (c) 5A06 electrode"

Tab.3

Pore structure parameters of flocs formed by different electrode systems"

电极
材料
比表面积/
(m2·g-1)
孔体积/
(cm3·g-1)
平均
孔径/nm
84.589 4 0.246 745 17.550 4
5052 72.739 3 0.225 419 17.439 1
5A06 70.334 4 0.192 861 16.630 9

Fig.3

N2 adsorption-desorption isotherms of flocs formed by different electrode systems. (a) Al electrode; (b) 5052 electrode; (c) 5A06 electrode"

Fig.4

Open circuit potential diagram of Al and Al-Mg alloy electrodes"

Fig.5

Polarization curves of Al and Al-Mg alloy electrodes. (a) Al electrode; (b) 5052 electrode; (c) 5A06 electrode"

Fig.6

Infrared images of Al and Al-Mg alloys. (a) Al; (b) 5052; (c) 5A06"

Fig.7

EDS mappings of Al electrode. (a) Before electrocoagulation; (b) After electrocoagulation; (c) Elements contents before and after flocculation"

Fig.8

EDS mappings of 5052 electrode. (a) Before electrocoagulation; (b) After electrocoagulation; (c) Element contents before and after flocculation"

Fig.9

EDS mappings of 5A06 electrode. (a) Before electrocoagulation; (b) After electrocoagulation; (c) Elements contents before and after flocculation"

[1] 吕伟伟, 姚继明, 张维. 电极材料对双池电化学降解靛蓝废水的影响[J]. 印染, 2019, 45(5): 8-14.
LV Weiwei, YAO Jiming, ZHANG Wei. Effect of different electrode materials on electrochemical degradation of indigo wastewater in double cell[J]. China Dyeing & Finishing, 2019, 45(5): 8-14.
[2] ZHANG W, YAO J M, MU Y G, et al. Electroflocculation of indigo dyeing wastewater from industrial production: flocs growth and adsorption mechanism[J]. Arabian Journal of Chemistry, 2023, 16(12): 105335.
doi: 10.1016/j.arabjc.2023.105335
[3] ZHANG W, ZHANG M D, YAO J M, et al. Industrial indigo dyeing wastewater purification: effective COD removal with peroxide-AC electrocoagulation system[J]. Arabian Journal of Chemistry, 2023, 16(4): 104607.
doi: 10.1016/j.arabjc.2023.104607
[4] LV H M, YANG S, LI C, et al. Suppressing passivation layer of Al anode in aqueous electrolytes by complexation of H2PO4 to Al3+ and an electrochromic Al ion battery[J]. Energy Storage Materials, 2021, 39: 412-418.
doi: 10.1016/j.ensm.2021.04.044
[5] SANEI E, MOKHTARANI N. Leachate post-treatment by electrocoagulation process: effect of polarity switching and anode-to-cathode surface area[J]. Journal of Environmental Management, 2022, 319: 115733.
doi: 10.1016/j.jenvman.2022.115733
[6] 田家宇, 霍佳文, 胡承志, 等. 电絮凝处理腐殖酸过程中阳极钝化影响因素分析[J]. 环境工程学报, 2022, 16(6): 1789-1796.
TIAN Jiayu, HUO Jiawen, HU Chengzhi, et al. Influence factors of anode passivation during humic acid electrocoagulation treatment[J]. Chinese Journal of Environmental Engineering, 2022, 16(6): 1789-1796.
[7] YU Y, ZHONG Y W, SUN W L, et al. A novel electrocoagulation process with centrifugal electrodes for wastewater treatment: electrochemical behavior of anode and kinetics of heavy metal removal[J]. Chemosphere, 2023, 310: 136862.
doi: 10.1016/j.chemosphere.2022.136862
[8] FERDIAN D, PRATESA Y, TOGINA I, et al. Development of Al-Zn-Cu alloy for low voltage aluminum sacrificial anode[J]. Procedia Engineering, 2017, 184: 418-422.
doi: 10.1016/j.proeng.2017.04.112
[16] SUN J Q, HUO J W, LI B W, et al. Anode passivation mitigation by homogenizing current density distribution in electrocoagulation[J]. Water Research, 2022, 223: 118966.
doi: 10.1016/j.watres.2022.118966
[17] GAO J X, FAN H F, WANG E D, et al. Exploring the effect of magnesium content on the electrochemical performance of aluminum anodes in alkaline batte-ries[J]. Electrochimica Acta, 2020, 353: 136497.
doi: 10.1016/j.electacta.2020.136497
[9] LINJEE S, MOONNGAM S, KLOMJIT P, et al. Corrosion behaviour improvement from the ultrafine-grained Al-Zn-In alloys in Al-air battery[J]. Energy Reports, 2022, 8: 5117-5128.
doi: 10.1016/j.egyr.2022.03.132
[10] DURA A, BRESLIN C B. Electrocoagulation using aluminium anodes activated with Mg, in and Zn alloying elements[J]. Journal of Hazardous Materials, 2019, 366: 39-45.
doi: S0304-3894(18)31123-3 pmid: 30502571
[11] 彭晶晶, 刘静, 张弦, 等. 合金元素在Al基牺牲阳极中的作用机理[J]. 材料导报, 2022, 36(17): 141-148.
PENG Jingjing, LIU Jing, ZHANG Xian, et al. Activation mechanisms of alloy elements on aluminum-based sacrificial anodes[J]. Materials Reports, 2022, 36(17): 141-148.
[12] 张梦迪, 张维, 姚继明. 天然黏土矿物在靛蓝染色废水电絮凝中的应用[J]. 纺织学报, 2022, 43(2): 196-201.
ZHANG Mengdi, ZHANG Wei, YAO Jiming. Application of natural clay minerals in electrocoagulation of indigo dyeing wastewater[J]. Journal of Textile Research, 2022, 43(2): 196-201.
[13] THOMMES M, KANEKO K, NEIMARK A V, et al. Physisorption of gases, with special reference to the evaluation of surface area and pore size distri-bution (IUPAC Technical Report)[J]. Pure and Applied Chemistry, 2015, 87(9/10): 1051-1069.
doi: 10.1515/pac-2014-1117
[14] 文九巴, 梁明岗, 贺俊光, 等. Mg与In合金化对Al-Ga-Mn阳极合金组织和性能影响[J]. 材料热处理学报, 2016, 37(3): 41-47.
WEN Jiuba, LIANG Minggang, HE Junguang, et al. Effect of Mg and in on microstructure and electrochemical performances of Al-Ga-Mn alloys[J]. Transactions of Materials and Heat Treatment, 2016, 37(3): 41-47.
[15] 张丽华. Cu元素对Al-Si合金的力学性能及耐腐蚀性的影响[J]. 陶瓷, 2020(4): 36-44.
ZHANG Lihua Effect of Cu on mechanical properties and corrosion resistance of Al-Si alloys[J]. Ceramics, 2020(4): 36-44.
[1] WANG Hongli, ZHANG Hui, LIU Jianyu, YU Haize, ZHANG Yaning, WANG Lili, XU Xuechao. Preparation and adsorption-photocatalytic performance of cotton-based biochar-ZIF-L(Zn)-chitosan/polypropylene composite membrane [J]. Journal of Textile Research, 2025, 46(09): 84-93.
[2] SHEN Chensi, WANG Xinyue, LI Fang. Integrated treatment and resource recovery technology of desizing wastewater through pre-oxidation and flocculation [J]. Journal of Textile Research, 2025, 46(08): 173-182.
[3] XIANG Wenlong, YANG Jingran, XIAO Xiaozhen. Preparation of Fe-Co bimetallic organic framework/rice husk composite material and its performance in dye decolorization [J]. Journal of Textile Research, 2025, 46(06): 178-186.
[4] WANG Wei, GAO Jiannan, PEI Xiaohan, LU Xin, SUN Yinyin, WU Jianbing. Fabrication and oil-water separation efficiency of cellulose/methyltrimethoxysilane aerogel [J]. Journal of Textile Research, 2025, 46(05): 135-142.
[5] JIN Rushi, CHEN Wanming, LIU Guojin, LIU Chenghai, QI Dongming, ZHAI Shimin. Application progress in biochars in printing and dyeing wastewater treatment [J]. Journal of Textile Research, 2025, 46(04): 235-243.
[6] LI Fengchun, SUN Hui, YU Bin, XIE Youxiu, ZHANG Dewei. Preparation of covalent organic framework/viscose spunlaced nonwoven fabrics and adsorption properties for dyestuff [J]. Journal of Textile Research, 2025, 46(02): 170-179.
[7] DAI Jiayang, HU Yifeng, WANG Yujing, WU Dongping, BIAN Xinger, XU Jianmei. Carbon footprint accounting and evaluation during silk refining stage [J]. Journal of Textile Research, 2024, 45(08): 190-197.
[8] YANG Liang, KONG Hanhan, LI Weilin, QI Xiaofen, ZHANG Tianyun, WANG Xuemei, LI Wenquan. Preparation of zeolitic imidazolate framework-8 and its adsorption performance on Congo Red [J]. Journal of Textile Research, 2024, 45(07): 140-149.
[9] WU Shouying, HUANG Qichao, ZHANG Kaifeng, ZHANG Linping, ZHONG Yi, XU Hong, MAO Zhiping. Construction of catalytic system by Fe(tpy)Cl3 complexes-activated periodate and its catalytic degradation mechanism for dyeing wastewater [J]. Journal of Textile Research, 2024, 45(06): 105-112.
[10] ZHENG Kang, GONG Wenli, BAO Jie, LIU Lin. Preparation and dynamic adsorption properties of amphoteric cellulose porous hydrogel spheres [J]. Journal of Textile Research, 2024, 45(05): 102-112.
[11] LU Yaoyao, YE Juntao, RUAN Chengxiang, LOU Jin. Preparation and photocatalytic performance of titanium dioxide/porous carbon nanofibers composite material [J]. Journal of Textile Research, 2024, 45(04): 67-75.
[12] LI Fang, ZHANG Yili, WANG Man, MENG Xiangzhou, SHEN Chensi. Acute toxic effects of antimony contaminants on green algae and cyanobacteria [J]. Journal of Textile Research, 2024, 45(04): 169-179.
[13] CHEN Rongxuan, SUN Hui, YU Bin. Preparation and photocatalytic properties of N-TiO2/ polypropylene melt-blown nonwovens [J]. Journal of Textile Research, 2024, 45(03): 137-147.
[14] HAN Bo, WANG Yulin, SHU Dawu, WANG Tao, AN Fangfang, SHAN Juchuan. Reactive dyeing using recycled dyeing wastewater [J]. Journal of Textile Research, 2023, 44(08): 151-157.
[15] WANG Guoqin, FU Xiaohang, ZHU Yuke, WU Liguang, WANG Ting, JIANG Xiaojia, CHEN Huali. Photodegradation mechanism and pathway of visible light-response mesoporous TiO2 for Rhodamine B [J]. Journal of Textile Research, 2023, 44(05): 155-163.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!