-
我国是全球最大的染料生产和消费国,染料产量约占全球70%,消费量约占全球55%。因此,我国印染废水产生量很大,据相关统计,纺织染料废水排放量每年超过2×109 t,约占全国废水排放的11%,已成为危害我国水生态安全的一大威胁[1-2]。亚甲基蓝作为一种阳离子染料被广泛应用于织物染色,亚甲基蓝染料不易降解,易引起人体皮肤过敏、呼吸困难、抽搐和角膜炎等症状[3-4],此外,亚甲基蓝废水可通过降低水体透明度、毒害水生生物进而破坏水体的自净功能[5-6]。
当前国内外多采用化学氧化法、吸附法、生化法或它们的优化组合方法对染料废水进行脱色处理[7-8]。其中,吸附法以其高效、操作简便、吸附剂类型多样等优势在染料废水处理中应用广泛[9-10]。活性炭作为常用吸附剂,在染料废水处理中存在运行成本高、难再生等问题[11];石墨烯[12]、膨润土[13]、珍珠岩[14]等吸附剂相对昂贵的价格限制了其应用;新型纳米材料及复合材料吸附剂存在水分散性能差等技术瓶颈[15-16]。基于上述原因,利用矿石、粉煤灰等廉价原料作吸附基质引起了广泛的兴趣[17-18]。钢渣是钢铁冶炼过程中产生的副产物之一,目前我国钢渣堆存量已达18×109 t,然而极低的综合利用率导致大量钢渣作为废弃物被填埋或堆放处理,这不仅占用土地资源,而且会造成土壤污染[11]。钢渣类型多样且多孔的结构特性使其作为吸附剂成为可能,已有研究证明,钢渣或改性钢渣在亚甲基蓝、直接大红4BE、碱性品红等染料废水处理中具有显著优势[19-20]。因此,以钢渣为吸附剂基质不仅可以达到染料废水脱色的目的,同时可以实现“以废治废”的环保理念。现有研究表明,原钢渣对亚甲基蓝染料废水的吸附效果较差,只有40%左右[21-22]。LDHs是主层板带正电荷、层间带有阴离子插层的层状双电子吸附剂,LDHs具有无毒无害、制备成本低、易生产、易再生以及经济效益高等优势,并且其独特的孔隙结构及较大的表面积使其在染料废水处理中具有一定的应用前景[23]。
目前,关于改性电炉原钢渣对亚甲基蓝吸附的研究鲜有报道。本研究旨在利用电炉钢渣为原料制备多元LDHs,并通过批式实验研究了不同环境因子对多元LDHs吸附亚甲基蓝的影响。采用XRD和BET手段对改性材料进行了表征分析。采用SEM和FT-IR技术及吸附动力学、吸附等温线和热力学方法探究了多元LDHs对亚甲基蓝染料废水的吸附过程及吸附机理。后续研究拟制备成吸附剂,应用于工业染料废水脱色环节或用作生态湿地填料去除水体色度。
改性电炉钢渣-多元LDHs对亚甲基蓝染的料脱色性能
Decolorization performance of methylene blue dye by the multi-LDHs of modified electric furnace steel slag
-
摘要: 研究了电炉钢渣改性材料——多元层状双金属氢氧化物(multivariate layered double hydroxide,多元LDHs)对亚甲基蓝染料的脱色性能。考察了亚甲基蓝染料初始质量浓度、吸附时间、吸附温度、pH和吸附剂投加量对吸附亚甲基蓝效果的影响。结果表明,当亚甲基蓝质量浓度为10 mg·L−1、pH为5.0、多元LDHs投加量为40 g·L−1时,多元LDHs对亚甲基蓝的吸附效果最佳,45 min内的去除率可达98.00%,120 min内基本完全去除。X射线衍射(XRD)表征结果表明,利用电炉原钢渣成功制备了多元LDHs;BET测试结果表明,多元LDHs的比表面积及孔容显著优于原钢渣。采用扫描电镜(SEM)和傅里叶变换红外光谱仪(FT-IR)技术对多元LDHs吸附亚甲基蓝前后形态特征以及关键官能团信息进行系统表征,结果表明,亚甲基蓝已成功吸附到多元LDHs上。吸附动力学研究表明,多元LDHs对亚甲基蓝的吸附过程中膜扩散和颗粒内扩散同时发生;吸附等温线拟合结果表明,该吸附过程符合Langmuir吸附等温模型;由热力学参数可知,多元LDHs对亚甲基蓝的去除为自发进行的、放热、以化学吸附为主的过程。以上研究结果可为电炉钢渣的资源化及其在亚甲基蓝废水处理中的应用提供参考。Abstract: In this study, the multivariate layered double hydroxide (multi-LDHs) material was prepared by modifying the electric furnace steel slag, and its decolorization properties of methylene blue dye was investigated. The effects of initial dye concentration, adsorption time, adsorption temperature, pH and multi-LDHs dosage on the adsorption of methylene blue solution onto multi-LDHs were investigated. The results indicated that under the optimal operating parameters of 10 mg·L−1 methylene blue, pH 5.0 and multi-LDHs dosage of 40 g·L−1, the maximum decolorization efficiency could reach 98% within 45 min and the dye was almost completely removed within 120 min. X-ray diffraction (XRD) results showed that the multi-LDHs have been successfully prepared from raw steel slag of electric furnace. BET test results demonstrated that the specific surface area and pore volume of multi-LDHs were significantly better than raw steel slag. The morphological characteristics and key functional groups of multi-LDHs pre-and post-adsorption of methylene blue were systematically characterized by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR), the results showed that methylene blue was successfully adsorbed on multi-LDHs. The adsorption kinetics confirmed that the membrane diffusion and intra-particle diffusion occurred simultaneously during the adsorption process of methylene blue by multi-LDHs. The fitting results of adsorption isotherm showed that the adsorption process conformed to the Langmuir isotherm model. The thermodynamic parameters indicated that methylene blue removal by multi-LDHs was spontaneous, exothermic and dominated by chemical adsorption. The above results can provide a reference for resource utilization of electric furnace slag and its application in methylene blue dye wastewater treatment.
-
表 1 多元LDHs对亚甲基蓝的吸附动力学参数
Table 1. Adsorption kinetic parameters of methylene blue by multi-LDHs
拟一级动力学 拟二级动力学 Elovich动力学 qe/(mg·g−1) K1/h−1 R2 qe/(mg·g−1) K2/h−1 R2 A B R2 0.332 0 0.010 6 0.474 8 0.855 7 0.088 5 0.999 9 0.026 7 0.163 5 0.997 6 表 2 吸附等温线参数
Table 2. Adsorption isotherm parameters
Freundlich Langmuir KF/(mg·g-1) n R2 qm/(mg·g-1) KL/(L·mg-1) R2 0.489 4 4.124 3 0.937 8 0.108 3 1.584 2 0.999 3 表 3 活化能及热力学参数
Table 3. Activation energy and thermodynamic parameters
T/K ΔG0/(kJ·mol−1) E/(kJ·mol−1) ΔS0/(J·(mol·K)−1) ΔH0/(kJ·mol−1) 277.15 −10.322 5 101.713 5 36.727 3 −0.143 5 288.15 −10.726 5 101.730 7 36.727 3 −0.143 5 298.15 −11.093 7 101.756 0 36.727 3 −0.143 5 308.15 −11.462 1 101.771 3 36.727 3 −0.143 5 -
[1] LIANG J, NING X, KONG M, et al. Elimination and ecotoxicity evaluation of phthalic acid esters from textile-dyeing wastewater[J]. Environmental Pollution, 2017, 231: 115-122. doi: 10.1016/j.envpol.2017.08.006 [2] PARROTT J L, BARTLETT A J, BALAKRISHNAN V K. Chronic toxicity of azo and anthracenedione dyes to embryo-larval fathead minnow[J]. Environmental Pollution, 2016, 210: 40-47. doi: 10.1016/j.envpol.2015.11.037 [3] SWAMY M M, NAGABHUSHANA B, KRISHNA R H, et al. Fast adsorptive removal of methylene blue dye from aqueous solution onto a wild carrot flower activated carbon: Isotherms and kinetics studies[J]. Water Treat, 2017, 71: 399-405. [4] CHENG S, ZHANG L, XIA H, et al. Adsorption behavior of methylene blue onto waste-derived adsorbent and exhaust gases recycling[J]. RSC Advances, 2017, 7(44): 27331-27341. doi: 10.1039/C7RA01482A [5] BAALAMURUGAN J, KUMAR V G, PRASAD B N, et al. Removal of cationic textile dye methylene blue (MB) using steel slag composite[J]. Rasayan Journal of Chemistry, 2020, 13: 1014-1021. doi: 10.31788/RJC.2020.1325715 [6] SELVAKUMAR S, MANIVASAGAN R, CHINNAPPAN K. Biodegradation and decolourization of textile dye wastewater using ganoderma lucidum[J]. 3 Biotech, 2013, 3(1): 71-79. doi: 10.1007/s13205-012-0073-5 [7] 隋智慧. 粉煤灰基混凝剂处理印染废水[J]. 印染, 2004, 30(20): 11-13. doi: 10.3321/j.issn:1000-4017.2004.20.004 [8] 白晓龙, 冯启言, 乔启成, 等. 酸性染料废水处理技术研究现状[J]. 印染助剂, 2020, 37(3): 16-19. doi: 10.3969/j.issn.1004-0439.2020.03.008 [9] GONZALEZ -ORTEGA M A, SEGURA I, CAVALARO S, et al. Radiological protection and mechanical properties of concretes with EAF steel slags[J]. Construction and Building Materials, 2014, 51: 432-438. doi: 10.1016/j.conbuildmat.2013.10.067 [10] 张峻搏. 钢渣对含磷废水及染料废水的吸附性能及应用研究[D]. 石家庄: 河北科技大学, 2020. [11] CHENG M, ZENG G, HUANG D, et al. High adsorption of methylene blue by salicylic acid-methanol modified steel converter slag and evaluation of its mechanism[J]. Journal of Colloid and Interface Science, 2018, 515: 232-239. doi: 10.1016/j.jcis.2018.01.008 [12] LIU T, LI Y, DU Q, et al. Adsorption of methylene blue from aqueous solution by graphene[J]. Colloids and Surfaces B:Biointerfaces, 2012, 90: 197-203. doi: 10.1016/j.colsurfb.2011.10.019 [13] HONG S, WEN C, HE J, et al. Adsorption thermodynamics of methylene blue onto bentonite[J]. Journal of Hazardous Materials, 2009, 167(1-3): 630-633. doi: 10.1016/j.jhazmat.2009.01.014 [14] DOGAN M, ALKAN M, ONGANER Y. Adsorption of methylene blue from aqueous solution onto perlite[J]. Water, Air, and Soil Pollution, 2000, 120(3): 229-248. [15] XU P, ZENG G M, HUANG D L, et al. Use of iron oxide nanomaterials in wastewater treatment: a review[J]. Science of the Total Environment, 2012, 424: 1-10. doi: 10.1016/j.scitotenv.2012.02.023 [16] YANG J M. A facile approach to fabricate an immobilized-phosphate zirconium-based metal-organic framework composite and its activity in the adsorption and separation of organic dyes[J]. Journal of Colloid and Interface Science, 2017, 505: 178-185. doi: 10.1016/j.jcis.2017.05.040 [17] 朱洪涛. 改性粉煤灰对活性艳兰染料吸附性能的研究[J]. 环境污染治理技术与设备, 2005, 6(3): 53-55. [18] 张勇, 吕瑞喜. 钢渣在污水治理中的应用[J]. 干旱环境监测, 2004, 18(4): 220-221. doi: 10.3969/j.issn.1007-1504.2004.04.008 [19] LE H S, TRAN X V, TRAN T, et al. Removal of nickel and methylene blue from aqueous solutions by steel slag as a low cost adsorbent[J]. Vietnam Journal of Science, Technology and Engineering, 2017, 59(4): 7-13. doi: 10.31276/VJSTE.59(4).07 [20] 赵艳锋, 王艳, 刘露. 钢渣处理碱性品红染料废水的实验研究[J]. 长春理工大学学报(自然科学版), 2011, 34(4): 91-93. [21] 胡恩柱, 李秋燕, 高涵, 等. 钢渣吸附去除水中亚甲基蓝[J]. 东北大学学报 (自然科学版), 2018, 39(4): 516. [22] 谢复青. 改性钢渣处理亚甲基蓝染料废水研究[J]. 针织工业, 2006(1): 68-70. doi: 10.3969/j.issn.1000-4033.2006.01.029 [23] 陈艳, 王丽秋, 王晨晔, 等. 以钢渣为原料合成层状双氢氧化物及其结构表征[J]. 化工学报, 2015, 66(12): 5149-5156. [24] TRAN H N, YOU S J, HOSSEINI-BANDEGHARAEI A, et al. Mistakes and inconsistencies regarding adsorption of contaminants from aqueous solutions: A critical review[J]. Water Research, 2017: 120. [25] DAS B, MONDAL N, BHAUMIK R, et al. Insight into adsorption equilibrium, kinetics and thermodynamics of lead onto alluvial soil[J]. International Journal of Environmental Science and Technology, 2014, 11(4): 1101-1114. doi: 10.1007/s13762-013-0279-z [26] 王晨晔, 陈艳, 郭占成, 等. 以钢渣为原料合成Ca-Mg-Al-Fe层状双金属氢氧化物及其对甲基橙的吸附[J]. 过程工程学报, 2018, 18(3): 570-574. doi: 10.12034/j.issn.1009-606X.217335 [27] 王蒙, 詹旭, 杨龙, 等. MgZnAl-LDHs和MgZnAlFe-LDHs对磷酸盐的吸附[J]. 环境工程学报, 2021, 15(9): 2935-2943. doi: 10.12030/j.cjee.202106113 [28] ZHANG L, LI Y J, YAN X B. Diffusion model and empirical study of the multi-generation products based on competition[J]. Systems Engineering-Theory & Practice, 2008, 28(12): 84-92. [29] DE Sá F P, CUNHA B N, NUNES L M. Effect of pH on the adsorption of Sunset Yellow FCF food dye into a layered double hydroxide (CaAl-LDH-NO3)[J]. Chemical Engineering Journal, 2013, 215: 122-127. [30] LI Y, GAO B, WU T, et al. Adsorption properties of aluminum magnesium mixed hydroxide for the model anionic dye Reactive Brilliant Red K-2BP[J]. Journal of Hazardous Materials, 2009, 164(2-3): 1098-1104. doi: 10.1016/j.jhazmat.2008.09.009 [31] 陈艳. 以钢渣为原料合成层状双氢氧化物及其用于印染废水处理[D]. 秦皇岛: 燕山大学, 2016. [32] 张迎. 改性MOF材料光催化降解染料废水性能研究[D]. 石家庄: 河北科技大学, 2019. [33] SHENG G, WANG S, HU J, et al. Adsorption of pb (II) on diatomite as affected via aqueous solution chemistry and temperature[J]. Golloids and Surfaces A:Physicochemical and Engineering Aspects, 2009, 339(1/2/3): 159-166.