-
近年来,随着我国医疗、畜禽和水产养殖等行业快速发展,抗生素的用量日益增加。磺胺甲噁唑(sulfamethoxazole, SMX)作为一种人工合成的广谱抗菌药物,频繁被用作渔药、兽药等大量排入环境水体中[1-3]。有关磺胺甲噁唑在不同水体环境中对不同对象造成的影响已有相关报道[4-6]。长期摄入SMX会损伤机体免疫力、影响动物发育、对地表水和地下水产生不可修复的损坏,严重破坏生态环境。
有研究表明,在废水处理中,传统的水处理技术如臭氧法[7]、离子交换法[8]对SMX的去除效果并不理想,光催化降解、生物降解等处理方法尽管已被证实能够有效去除SMX,但其价格昂贵且会生成中间产物[9-10]。吸附法是一种成熟的水处理方法,因吸附剂具有简单高效、可以重复利用等特点,故其应用较为广泛,被认为是能有效去除SMX的方法之一[11-12]。常见的吸附剂有活性炭、石墨烯、碳纳米管等,对污染物具有良好的吸附去除效果[13-14]。NAM等[15]用经过超声处理后的氧化石墨烯吸附磺胺甲噁唑,去除率约为30%。MOUNI等[16]用硫酸氧化改性杏壳活性炭吸附水溶液中Pb2+,最大吸附量为21.38 mg·g−1。但吸附剂的经济性、环保性是影响其广泛应用的首要条件,因此,将廉价易得的生物质制备成生物炭材料近年来广受关注。
松针作为生物炭材料的一种,具有四季均可采收、高产出量的特点,将废弃的松针用于磺胺甲恶唑的去除,既为水处理技术提供了一种新思路,又完成了废弃松针的资源化转化。AHMAD等[17]利用在300、500、700 ℃下制备得到的松针生物炭吸附三氯乙烯,结果表明,700 ℃制备得到的松针生物炭表面疏水性高、表面积大、有利于吸附,其对三氯乙烯的去除效果最好。改性会使生物炭的孔隙结构、比表面积等发生改变,合适的改性方法对废水中污染物的去除有实际应用意义。改性方法有许多,包括金属负载改性和氧化改性等[18]。常用的氧化剂有盐酸、硝酸、氢氧化钠、过氧化氢等。ZHANG等[19]用磷酸盐改性后的竹炭生物炭,其吸附Cd(Ⅱ)能力较原始竹炭提高近10倍,对Cd(Ⅱ)的去除率可达85.78%。张江等[20]使用海藻酸钠和氯化铁溶液制备改性石墨烯-生物炭复合材料吸附磺胺嘧啶,平衡时吸附量在20 mg·kg−1以上。本研究以常见的松针为原料,利用盐酸制备出松针生物炭,吸附去除水体中的磺胺甲噁唑,通过FT-IR、SEM、BET对其进行了微观表征,分别考察了PBC投加量、pH、阴离子等对SMX去除效果的影响,并采用吸附等温模型和吸附动力学模型进行分析研究,从而探讨了其吸附机制,为生物炭的实际应用提供参考。
盐酸改性松针生物炭对磺胺甲噁唑的吸附性能
Adsorption performance of hydrochloric acid-modified pine needle biochar on sulfamethoxazolef
-
摘要: 以松针为原料,使用盐酸活化制备获得松针生物炭(PBC),将其用于吸附去除水体中的磺胺甲噁唑(SMX)。分别考察了投加量、pH、吸附时间、阴离子浓度等因素对PBC吸附性能的影响,采用吸附动力学模型和吸附等温模型对吸附过程进行了拟合分析。FT-IR、SEM和BET表征结果证明,经盐酸活化后的松针生物炭表面疏松多孔,含有羧基和羟基等含氧官能团。吸附实验结果表明:当PBC投加量为0.4 g·L−1时,吸附60 min后SMX去除率可达97.1%;当pH为4.0~8.0时,随着pH升高,PBC对SMX的去除率下降;
${{\rm{CO}}_3^{2 - }}$ 和${{\rm{HCO}}_3^{- }}$ 对吸附反应起抑制作用,${{\rm{CO}}_3^{2 - }}$ 抑制作用更强,${{\rm{SO}}_4^{2 - }}$ 对吸附过程影响较小;PBC对SMX的吸附可用准二级动力学方程来描述,与Freundlich等温方程式拟合度更好(R2>0.98);热力学数据表明PBC对SMX的吸附过程是自发的吸热反应;5次实验后PBC对SMX的去除率仍在40%以上。考虑到PBC吸附效果好,可重复利用,说明PBC具有良好的应用前景,研究可为水污染治理的应用提供参考。Abstract: The pine needle biochar (PBC) was prepared with resource of pine needles and activation agent of hydrochloric acid, and was used to adsorb and remove sulfamethoxazole (SMX). The effects of dosage, pH value, initial pH, adsorption time and concentration of coexistence anions on the adsorption performance of PBC were investigated. The adsorption kinetics model and adsorption isotherm model were used to conduct the fitting analysis. The characterization results of scanning electron microscopy (SEM), Surface area analysis (BET) and Fourier transform infrared spectroscopy (FT-IR) demonstrated that the pine needle biochar activated by hydrochloric acid had loose and porous surface and contained oxygen functional groups such as carboxyl groups and hydroxyl groups. The removal rate of SMX reached 97.1% after 60min adsorption at PBC dosage of 0.4 g·L−1. Within the pH range from 4.0 to 8.0, SMX removal rate by PBC decreased as pH increased. Both${\rm{CO}}_3^{2 - }$ and${\rm{HCO}}_3^{- }$ inhibited the adsorption reaction and the former was stronger.${\rm{SO}}_4^{2 - }$ had slight effect on the adsorption process. The SMX adsorption by PBC could be described by quasi-second-order kinetic equation, and be better fitted by Freundlich isotherm equation (R2>0.98). The thermodynamic parameters indicated that the adsorption process of PBC to SMX was a spontaneous endothermic reaction. The SMX removal rate by PBC was still above 40% after five recycles. Considering the good adsorption and recycle effects, PBC has a good application prospect. This study can provide reference for its application in water pollution control.-
Key words:
- pine needle biochar /
- adsorption /
- sulfamethoxazole
-
表 1 PBC的比表面积与孔径结构分析
Table 1. Analysis of specific surface area and pore structure of PBC
样品 SBET/(m2·g−1) Vt/(cm3·g−1) Vmic/(cm3·g−1) dp/nm 吸附前 391.0 0.194 6 0.113 1 1.990 7 吸附后 273.2 0.104 7 0.098 0 1.963 8 表 2 PBC对SMX的吸附动力学拟合参数
Table 2. Kinetics parameters for SMX adsorption on PBC
样品 准一级动力学方程 准二级动力学方程 颗粒内扩散方程 qe/(mg·g−1) k1/min−1 R2 kF/(mg·g−1) n/(g·(mg·min)−1) R2 k3/(mg·(g·min1/2)−1) R2 BC 7.55 2.72×10−2 0.956 6 13.87 7.21×10−2 0.999 1 1.23 0.992 4 PBC 11.69 1.56×10−2 0.861 0 24.79 4.03×10−2 0.997 7 2.83 0.972 1 表 3 PBC对SMX的吸附等温线拟合参数
Table 3. Isotherms parameters for SMX adsorption on PBC
T/℃ Langumuie模型 Freundlich模型 qm/(mg·g−1) kL/(L·mg−1) R2 KF/(mg·g−1) n R2 283 43.43 2.03 0.874 7 19.44 4.28 0.980 2 298 44.59 2.28 0.893 2 22.62 4.15 0.983 2 313 45.79 2.41 0.874 3 24.57 4.03 0.980 6 表 4 PBC对SMX的吸附热力学参数
Table 4. Thermodynamic parameters of SMX adsorption on PBC
温度/K ΔG/(kJ·mol−1) ΔH/(kJ·mol−1) ΔS/(J·(K·mol)−1) 283 −6.98 5.77 45.14 298 −7.73 313 −8.33 -
[1] LIU L, HU S, SHEN G, et al. Adsorption dynamics and mechanism of aqueous sulfachloropyridazine and analogues using the root powder of recyclable long-root, Eichhornia crassipes[J]. Chemosphere, 2018, 196(3): 409-417. [2] 杨帅, 余晓敏, 郭学博, 等. 二氧化氯对典型磺胺类抗生素的降解机制[J]. 环境化学, 2019, 38(1): 38-45. [3] 陈哲, 吴立明, 苏怡. 生活饮用水中磺胺类抗生素污染现状及其控制的研究进展[J]. 上海预防医学, 2018, 30(5): 80-83. [4] 吴娜娜, 钱虹, 李亚峰. 水中磺胺类抗生素去除技术研究进展[J]. 建筑与预算, 2017, 10(6): 43-50. [5] QIU J R, ZHAO T, LIU Q Y, et al. Residual veterinary antibiotics in pig excreta after oral administration of sulfonamides[J]. Environmental Geochemistry & Health, 2016, 38(2): 549-556. doi: 10.1007/s10653-015-9740-x [6] LI X D, YU H X, XU S S, et al. Uptake of three sulfonamides from contaminated soil by pakchoi cabbage[J]. Ecotoxicology and Environmental Safety, 2013, 92(3): 297-302. [7] 郑吉, 周振超, 陈芳, 等. 3种常规消毒方法对磺胺类抗性基因削减效果的比较[J]. 环境科学, 2017, 38(4): 1497-1505. [8] LEVCHU I, RUEDA M J J, SILLANPÄÄ M. Removal of natural organic matter (NOM) from water by ion exchange: A review[J]. Chemosphere, 2017, 192: 90-104. [9] 刘吉开, 万甜, 程文, 等. 饮用水中典型磺胺类抗生素的深度处理工艺对比[J]. 净水技术, 2018, 37(7): 44-49. [10] WANG C, YAO X, WANG P, et al. Effects of water environmental factors on the photocatalytic degradation of sulfamethoxazole by AgI/UiO-66 composite under visible light irradiation[J]. Journal of Alloys & Compounds, 2018, 748(5): 314-322. [11] ZHANG C, LAI C, ZENG G M, et al. Efficacy of carbonaceous nanocomposites for sorbing ionizable antibiotic sulfamethazine from aqueous solution[J]. Water Research, 2016, 95(14): 103-112. [12] RUI L, ZHANG Y L, CHU W L, et al. Adsorptive removal of antibiotics from water using peanut shells from agricultural waste[J]. RSC Advances, 2018, 24(8): 13546-13555. doi: 10.1039/C7RA11796E [13] 王栋纬, 宋燕西, 冶晓凡, 等. 氧化石墨烯对磺胺甲恶唑和磺胺甲基嘧啶的吸附性能研究[J]. 分析化学, 2018, 46(2): 211-216. doi: 10.11895/j.issn.0253-3820.171279 [14] WU J, ZHAO H, CHEN R, et al. Adsorptive removal of trace sulfonamide antibiotics by water-dispersible magnetic reduced graphene oxide-ferrite hybrids from wastewater[J]. Journal of Chromatography B, 2016, 1029-1030: 106-112. doi: 10.1016/j.jchromb.2016.07.018 [15] NAM S W, JUNG C, LI H, et al. Adsorption characteristics of diclofenac and sulfamethoxazole to graphene oxide in aqueous solution[J]. Chemosphere, 2015, 136(3): 20-26. [16] MOUNI L, MERABET D, BOUZAZA A, et al. Adsorption of Pb(II) from aqueous solutions using activated carbon developed from Apricot stone[J]. Desalination, 2013, 276(1): 148-153. [17] AHMAD M, LEE S, RAJAPAKSHA A, et al. Trichloroethylene adsorption by pine needle biochars produced at various pyrolysis temperatures[J]. Bioresource Technology, 2013, 143(1): 615-622. [18] FENG Z, ZHU L. Sorption of phenanthrene to biochar modified by base[J]. Frontiers of Environmental Science & Engineering, 2018, 12(2): 1. [19] ZHANG S, ZHANG H, CAI J, et al. Evaluation and prediction of cadmium removal from aqueous solution by phosphate-modified activated bamboo biochar[J]. Energy & Fuels, 2017: 32(4): 4469-4477. [20] 张江, 孙宁宁, 张景环, 等. 改性石墨烯-生物炭复合材料对磺胺类抗生素的吸附[J]. 山东化工, 2017, 46(23): 39-39. doi: 10.3969/j.issn.1008-021X.2017.23.016 [21] 房聪, 房烽, 张黎明, 等. 秸秆活性炭活化过一硫酸盐降解酸性橙7[J]. 环境科学学报, 2018, 38(1): 242-250. [22] 朱青. 改性生物炭对水中磺胺嘧啶的去除试验研究[D]. 济南: 山东师范大学, 2018. [23] CICEK F, DURSUN O, AHMET O, et al. Low cost removal of reactive dyes using wheat bran[J]. Journal of Hazardous Materials, 2007, 146(1): 408-416. [24] LUCIDA H, PARKIN J E, UNDERLAND V B. Kinetic study of the reaction of sulfamethoxazole and glucose under acidic conditions: I. Effect of pH and temperature[J]. International Journal of Pharmaceutics, 2000, 202(1): 47-62. [25] ZHENG H, WANG Z Y, JIAN Z, et al. Sorption of antibiotic sulfamethoxazole varies with biochars produced at different temperatures[J]. Environmental Pollution, 2013, 181(56): 60-67. [26] TEIXIDÓ M, PIGNATELLO J J, BELTRÁN J L, et al. Speciation of the ionizable antibiotic sulfamethazine on black carbon (biochar)[J]. Environmental Science & Technology, 2011, 45(23): 10020-10027. [27] CHIOU C T, MALCOML R L, BRINTON T I, et al. Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids[J]. Environmental Science & Technology, 1986, 20(5): 502-508. [28] TAQVI S I H, HASANY S M, BHANGER M I. Sorption profile of Cd (II) ions onto beach sand from aqueous solutions[J]. Journal of Hazardous Materials, 2007, 141(1): 37-44. doi: 10.1016/j.jhazmat.2006.06.080 [29] DANMALIKI G I, SALEH T A. Influence of conversion parameters of waste tires to activated carbon on adsorption of dibenzothiophene from model fuels[J]. Journal of Cleaner Production, 2016, 117: 50-55. doi: 10.1016/j.jclepro.2016.01.026 [30] 吕迪. 改性活性炭吸附水中内分泌干扰物双酚A的研究[D]. 杭州: 浙江工业大学, 2017. [31] LIU T, XIE Z, ZHANG Y, et al. Preparation of cationic polymeric nanoparticles as an effective adsorbent for removing diclofenac sodium from water[J]. RSC Advances, 2017, 61(7): 38279-38286. doi: 10.1039/C7RA06730E