Effect of hydrated ferric oxide loadings on structure and phosphate adsorption of acrylic polymer-supported composite adsorbents
-
摘要: 为优化丙烯酸树脂基水合氧化铁(Hydrated ferric oxide,HFO)复合吸附剂的负载量,调节FeCl3浓度制备出5种复合吸附剂(HFO负载量分别为5.3wt%、8.6wt%、12.1wt%、14.9wt%和18.5wt%,以Fe质量分数计),分析其结构性能,并考察D213-HFO复合吸附剂对磷的吸附等温线、吸附动力学、pH和共存离子影响及洗脱效果。结果表明,复合吸附剂负载HFO颗粒为纳米无定型HFO,在直径方向呈U型分布。此外,随HFO负载量增加,磷吸附容量先升高后下降,负载量为14.9wt%的复合吸附剂吸附容量最大(19.04 mg·g−1)。复合吸附剂吸附磷在240 min达到平衡,更符合准一级动力学模型(R2>0.99)。磷吸附最佳pH为6~8,当SO42−≥600 mg·L−1树脂对磷无吸附效果,而负载HFO吸附磷不受影响。在连续4个吸附-洗脱周期内,5wt%的NaOH和5wt%的NaCl溶液对磷的洗脱率均接近100%。实验表明,复合吸附剂的吸附容量随HFO负载量增加先升高后下降,而结构性能、吸附平衡时间、pH适应范围、共存离子影响及洗脱效果无显著差异。Abstract: In order to optimize the hydrated ferric oxide (HFO) loadings of acrylic resin-based HFO composite adsorbents, five composite adsorbents were prepared by regulating FeCl3 concentration, and the HFO loadings were 5.3wt%, 8.6wt%, 12.1wt%, 14.9wt% and 18.5wt% (mass fraction in Fe), respectively. The structure properties of composite adsorbents were analyzed. Furthermore, the adsorption performance of composite adsorbents in removing phosphate were investigated, including adsorption isotherms, adsorption kinetics, effect of pH and coexisting anion, and elution effect. The results show that HFO nanoparticles dispersed into composite adsorbents are amorphous in nature, and the radial distribution of HFO obeys U-type distribution. Moreover, the phosphate adsorption capacity increases with the HFO loadings and then decreases, and the adsorption capacity of the composite adsorbent with HFO loading of 14.9wt% is the maximum (19.04 mg·g−1). The contact time of 240 min is long enough for composite adsorbents to achieve adsorption equilibrium, and the adsorption kinetic curves of the composite adsorbents are fitted well with pseudo-first order kinetic model (R2>0.99). The optimal pH for phosphate adsorption is 6~8. Furthermore, there is no phosphate adsorption by resin when the concentration of SO42− is equal or greater than 600 mg·L−1, while it does not pose any noticeable effect on phosphate adsorption by the loaded HFO nanoparticles. The regeneration efficiencies approach 100% by a binary 5wt% NaOH and 5wt% NaCl solution during 4 continuous adsorption-regeneration cycles. The experiments show that the phosphate adsorption capacity of the composite adsorbents increases with the HFO loadings and then decreases, while there is no significant difference in structure property, adsorption equilibrium time, pH range, effect of coexisting anion, and elution effect.
-
Key words:
- adsorbent /
- hydrated ferric oxide /
- acrylic resin /
- phosphate /
- structure
-
表 1 不同FeCl3浓度制备的复合吸附剂
Table 1. Composite adsorbents prepared with various FeCl3 concentrations
FeCl3 concentration/(mol·L−1) HFO loading/wt% Adsorbent 0.35 5.3 D213-5.3HFO 0.5 8.6 D213-8.6HFO 1.0 12.1 D213-12.1HFO 1.3 14.9 D213-14.9HFO 2.5 18.5 D213-18.5HFO Note: HFO—Hydrated ferrous oxide. 表 2 D213和D213-14.9HFO复合吸附剂的孔特征参数
Table 2. Porous characteristics of D213 and D213-14.9HFO composite adsorbents
Adsorbent D213 D213-14.9HFO Surface area/(m2·g−1) 4.46 6.51 Pore volume/(cm3·g−1) 0.011 0.008 Mean pore size/nm 9.43 7.67 表 3 D213-HFO复合吸附剂的Freundlich模型和Langmuir模型拟合参数
Table 3. Isothermal adsorption model fitting parameters of Langmuir and Freundlich model by D213-HFO composite adsorbents
Adsorbents Langmuir model Freundlich model qm/(mg·g−1) b/(L·mg−1) R2 Kf/(mg1−1/n·L1/n·g−1) n R2 D213-5.3HFO 8.98 0.10 0.973 1.29 2.30 0.982 D213-8.6HFO 9.20 0.23 0.964 2.24 2.49 0.972 D213-12.1HFO 15.80 0.19 0.946 3.40 2.18 0.976 D213-14.9HFO 19.04 0.16 0.964 3.76 2.33 0.973 D213-18.5HFO 18.55 0.17 0.941 3.74 2.68 0.964 Notes: qm―Maximum adsorption capacity; b, Kf and n―Isotherm constants. 表 4 D213和D213-HFO复合吸附剂的吸附动力学拟合参数
Table 4. Kinetic fitting parameters of D213 and D213-HFO composite adsorbents
Adsorbent Pseudo-first-order Pseudo-second-order Intra-particle diffusion qe/(mg·g−1) k1/min−1 R2 qe/(mg·g−1) k2/(g·mg−1·min−1) R2 C kd/(mg·g−1·min−1/2) R2 D213 15.23 0.028 0.998 17.32 20.9 0.978 2.816 0.842 0.791 D213-5.3HFO 16.92 0.023 0.999 20.26 11.9 0.976 2.248 0.975 0.840 D213-8.6HFO 17.84 0.021 0.999 21.60 10.2 0.979 2.119 1.037 0.853 D213-12.1HFO 19.66 0.017 0.999 24.79 6.54 0.988 1.507 1.163 0.896 D213-14.9HFO 19.65 0.018 0.999 24.49 7.07 0.989 1.719 1.155 0.892 D213-18.5HFO 19.61 0.015 0.999 25.47 5.06 0.993 0.980 1.161 0.925 Notes: k1―Pseudo-first-order kinetic constant; k2―Pseudo-second-order kinetic constant; qe―Phosphate adsorption capacity in equilibrium; kd―Intra-particle diffusion rate constant; C―Reaction constant. -
[1] CONLEY D J, PAERL H W, HOWARTH R W, et al. Controlling eutrophication: Nitrogen and phosphorus[J]. Science,2009,323(5917):1014-1015. doi: 10.1126/science.1167755 [2] AWUAL M R. Efficient phosphate removal from water for controlling eutrophication using novel composite adsorbent[J]. Journal of Cleaner Production,2019,228:1311-1319. doi: 10.1016/j.jclepro.2019.04.325 [3] ZHANG Z, WANG Y, LESLIE G L, et al. Effect of ferric and ferrous iron addition on phosphorus removal and fouling in submerged membrane bioreactors[J]. Water Research,2015,69:210-222. doi: 10.1016/j.watres.2014.11.011 [4] MAHARDIKA D, PARK H S, CHOO K H. Ferrihydrite-impregnated granular activated carbon (FH@GAC) for efficient phosphorus removal from wastewater secondary effluent[J]. Chemosphere,2018,207:527-533. doi: 10.1016/j.chemosphere.2018.05.124 [5] XIA W, XU L, YU L, et al. Conversion of municipal wastewater-derived waste to an adsorbent for phosphorus recovery from secondary effluent[J]. Science of The Total Environment,2020,705:135959. doi: 10.1016/j.scitotenv.2019.135959 [6] LOGANATHAN P, VIGNESWARAN S, KANDASAMY J, et al. Removal and recovery of phosphate from water using sorption[J]. Critical Reviews in Environmental Science and Technology,2014,44(8):847-907. doi: 10.1080/10643389.2012.741311 [7] ZHANG H, ELSKENS M, CHEN G, et al. Influence of seawater ions on phosphate adsorption at the surface of hydrous ferric oxide (HFO)[J]. Science of The Total Environment,2020,721:137826. doi: 10.1016/j.scitotenv.2020.137826 [8] LIN J, ZHAO Y, ZHAN Y, et al. Influence of coexisting calcium and magnesium ions on phosphate adsorption onto hydrous iron oxide[J]. Environmental Science and Pollution Research,2020,27(10):11303-11319. doi: 10.1007/s11356-020-07676-w [9] 董浩, 花铭. 树脂基纳米复合材料吸附水中As(III)的性能比较研究[J]. 离子交换与吸附, 2017, 33(5):385-394.DONG Hao, HUA Ming. Comparative study of arsenite removal from water by polymer-supported hydrated metallic oxides[J]. Ion Exchange and Adsorption,2017,33(5):385-394(in Chinese). [10] SURESH K P, PROT T, KORVING L, et al. Effect of pore size distribution on iron oxide coated granular activated carbons for phosphate adsorption-Importance of mesopores[J]. Chemical Engineering Journal,2017,326:231-239. doi: 10.1016/j.cej.2017.05.147 [11] WANG Z, LIN Y, WU D, et al. Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture[J]. Chemosphere,2016,144:1290-1298. doi: 10.1016/j.chemosphere.2015.10.015 [12] MUHAMMAD A, SOARES A, JEFFERSON B. The impact of background wastewater constituents on the selectivity and capacity of a hybrid ion exchange resin for phosphorus removal from wastewater[J]. Chemosphere,2019,224:494-501. doi: 10.1016/j.chemosphere.2019.01.085 [13] 赵继旭, 胡建龙, 邵立南, 等. HCl浓度对水合氧化铁复合吸附剂磷吸附效能的影响[J]. 复合材料学报, 2021, 38(4):1139-1146.ZHAO Jixu, HU Jianlong, SHAO Li’nan, et al. Effect of HCl concentration on phosphate adsorption behavior of hydrated ferrous oxide composite adsorbents[J]. Acta Materiae Compositae Sinica,2021,38(4):1139-1146(in Chinese). [14] 刘艳, 高洋, 赵昕, 等. 凝胶型树脂载纳米水合氧化铁复合材料的制备与除As(V)特性[J]. 高分子学报, 2018(7):939-948.LIU Yan, GAO Yang, ZHAO Xin, et al. A gel resin-supported nano-hydrated iron oxide for arsenate sorption from water[J]. Acta Polymerica Sinica,2018(7):939-948(in Chinese). [15] DENG Y, ZHANG Q, ZHANG Q, et al. Arsenate removal from underground water by polystyrene-confined hydrated ferric oxide (HFO) nanoparticles: Effect of humic acid[J]. Environmental Science and Pollution Research,2020,27(7):6861-6871. doi: 10.1007/s11356-019-07282-5 [16] PAN B, WU J, PAN B, et al. Development of polymer-based nanosized hydrated ferric oxides (HFOs) for enhanced phosphate removal from waste effluents[J]. Water Research,2009,43(17):4421-4429. doi: 10.1016/j.watres.2009.06.055 [17] BLANEY L M, CINAR S, SENGUPTA A K. Hybrid anion exchanger for trace phosphate removal from water and wastewater[J]. Water Research,2007,41(7):1603-1613. doi: 10.1016/j.watres.2007.01.008 [18] 曹顺安, 杨苑霖, 郑观文. 离子交换树脂有机物污染处理及预防措施[J]. 水处理技术, 2017, 43(2):14-17.CAO Shun’an, YANG Yuanlin, ZHENG Guanwen. Treatment and precaution measures of the ion exchange resin polluted by organic substances[J]. Technology of Water Treatment,2017,43(2):14-17(in Chinese). [19] BERIL G Z, KAYA Y, VERGILI I, et al. Capacity loss in an organically fouled anion exchanger[J]. Desalination,2006,189(1-3):303-307. doi: 10.1016/j.desal.2005.07.012 [20] 王钇, 李颖瑜, 王津南, 等. 阴离子交换树脂骨架结构对吸附单宁酸与五倍子酸的影响[J]. 离子交换与吸附, 2016, 32(1):1-13.WANG Yi, LI Yingyu, WANG Jinnan, et al. Effect of skeleton structure of anion exchange resin on adsorption performance of tannic acid and gallic acid[J]. Ion Exchange and Adsorption,2016,32(1):1-13(in Chinese). [21] SHUANG C, WANG J, LI H, et al. Effect of the chemical structure of anion exchange resin on the adsorption of humic acid: Behavior and mechanism[J]. Journal of Colloid and Interface Science,2015,437:163-169. doi: 10.1016/j.jcis.2014.09.011 [22] 中国石油和化学工业联合会. 离子交换树脂预处理方法: GB/T 5476—2013[S]. 北京: 中国标准出版社, 2013.China Petroleum and Chemical Industry Federation. Methods of pretreating ion exchange resin: GB/T 5476—2013[S]. Beijing: China Standards Press, 2013(in Chinese). [23] 国家环境保护局标准处. 钼酸铵分光光度法: GB/T 11893—1989[S]. 北京: 中国标准出版社, 1989.Standards Division of State Environmental Protection Administration. Ammonium molybdate spectrophotometric method: GB/T 11893—1989[S]. Beijing: China Standards Press, 1989(in Chinese). [24] SU Y, CUI H, LI Q, et al. Strong adsorption of phosphate by amorphous zirconium oxide nanoparticles[J]. Water Research,2013,47(14):5018-5026. doi: 10.1016/j.watres.2013.05.044 [25] ALSHEHRI S M, NAUSHAD M, AHAMAD T, et al. Synthesis, characterization of curcumin based ecofriendly antimicrobial bio-adsorbent for the removal of phenol from aqueous medium[J]. Chemical Engineering Journal,2014,254:181-189. doi: 10.1016/j.cej.2014.05.100 [26] GONG C, CHEN D, JIAO X, et al. Continuous hollow α-Fe2O3 and α-Fe fibers prepared by the sol-gel method[J]. Journal of Materials Chemistry,2002,12(6):1844-1847. doi: 10.1039/b201243j [27] LI S, YANG Q, ZHONG Y, et al. Adsorptive bromate removal from aqueous solution by commercial strongly basic resin impregnated with hydrated ferric oxide (hfo): Kinetics and equilibrium studies[J]. Journal of Chemical & Engineering Data,2016,61(3):1305-1312. [28] ZHOU K, WU B, SU L, et al. Enhanced phosphate removal using nanostructured hydrated ferric-zirconium binary oxide confined in a polymeric anion exchanger[J]. Chemical Engineering Journal,2018,345:640-647. doi: 10.1016/j.cej.2018.01.091 [29] WANG J, ZHANG S, PAN B, et al. Hydrous ferric oxide-resin nanocomposites of tunable structure for arsenite removal: Effect of the host pore structure[J]. Journal of Hazardous Materials,2011,198:241-246. doi: 10.1016/j.jhazmat.2011.10.036 [30] KARIM A H, JALIL A A, TRIWAHYONO S, et al. Amino modified mesostructured silica nanoparticles for efficient adsorption of methylene blue[J]. Journal of Colloid and Interface Science,2012,386(1):307-314. doi: 10.1016/j.jcis.2012.07.043 [31] ZENG H, FISHER B, GIAMMAR D E. Individual and competitive adsorption of arsenate and phosphate to a high-surface-area iron oxide-based sorbent[J]. Environmental Science & Technology,2008,42(1):147-152. [32] 许建红, 高乃云, 唐玉霖, 等. 浅析水合氧化铁的研究进展[J]. 水处理技术, 2011, 37(8):22-25.XU Jianhong, GAO Naiyun, TANG Yulin, et al. Analysis of hydrous ferric oxide research[J]. Technology of Water Treatment,2011,37(8):22-25(in Chinese). [33] KHARE N, HESTERBERG D, MARTIN J D. XANES investigation of phosphate sorption in single and binary systems of iron and aluminum oxide minerals[J]. Environmental Science & Technology,2005,39(7):2152-2160. [34] LEFEVRE G. In situ Fourier-transform infrared spectroscopy studies of inorganic ions adsorption on metal oxides and hydroxides[J]. Advances in Colloid and Interface Science,2004,107(2):109-123.