Novel biomass-derived porous iron/carbon materials for highly efficient cadmium removal and its mechanisms

ZHU Zhenlong; LI Fangbai; LIU Kai; GAO Baolin; FANG Liping

doi:10.12030/j.cjee.202201114

2022 Volume 16 Issue 6

Article Contents

Previous Article Next Article

ZHU Zhenlong, LI Fangbai, LIU Kai, GAO Baolin, FANG Liping. Novel biomass-derived porous iron/carbon materials for highly efficient cadmium removal and its mechanisms[J]. Chinese Journal of Environmental Engineering, 2022, 16(6): 1779-1788. doi: 10.12030/j.cjee.202201114

Citation:

ZHU Zhenlong, LI Fangbai, LIU Kai, GAO Baolin, FANG Liping. Novel biomass-derived porous iron/carbon materials for highly efficient cadmium removal and its mechanisms[J]. Chinese Journal of Environmental Engineering, 2022, 16(6): 1779-1788. doi: 10.12030/j.cjee.202201114

Novel biomass-derived porous iron/carbon materials for highly efficient cadmium removal and its mechanisms

1.
College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541006, China
2.
Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
3.
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China

Corresponding author: FANG Liping, lpfang@soil.gd.cn
Received Date: 18/01/2022
Available Online: 10/06/2022

Abstract

In this study, a type of novel biomass-derived porous iron/carbon material was prepared by the high-temperature carbothermal reduction method under anaerobic conditions, and its structure and properties were analyzed in detail. The effects of environmental factors during preparation including pyrolysis temperature, pH, and co-existing ions on the performance of cadmium (Cd) removal were investigated, and the corresponding Cd fixation mechanism by this iron/carbon material was revealed. The results show that the specific surface area and pore volume of the material increased with the increase of the pyrolysis temperature, and nanoscale zero-valent iron and iron carbide occurred at 800℃, a magnetic iron/carbon-based functional material (MCFe-800) was prepared, which was beneficial to the magnetic recovery. The adsorption kinetic experiment results show that the removal efficiency of Cd by MCFe-800 was significantly higher than that of other pyrolysis temperatures, and the maximum removal capacity normalized to iron was 463.84 mg·g⁻¹. It is more favorable for Cd removal by MCFe-800 under neutral conditions. The removal mechanisms of Cd were mainly electrostatic adsorption, co-precipitation, and surface complexation. In addition, after four cycles, the removal efficiency of Cd by MCFe-800 in real water was still 75.0%. Filter column experiments show that the treatment capacities of MCFe-800 were 400 BV and 270 BV when the initial concentrations of Cd(II) were 1 000 μg·L⁻¹ and 2 000 μg·L⁻¹, respectively. Therefore, the novel biomass-derived porous iron/carbon material has a great application potential for the remediation of Cd pollution in water.
- iron/carbon materials,
- cadmium,
- water treatment

References

[1]	DU Y, HU X F, WU X H, et al. Effects of mining activities on Cd pollution to the paddy soils and rice grain in Hunan province, Central South China[J]. Environmental Monitoring and Assessment, 2013, 185(12): 9843-9856. doi: 10.1007/s10661-013-3296-y CrossRef Google Scholar Pub Med
[2]	TALABI A O, KAYODE T J. Groundwater pollution and remediation[J]. Journal of Water Resource and Protection, 2019, 11(01): 1. doi: 10.4236/jwarp.2019.111001 CrossRef Google Scholar Pub Med
[3]	WANG P, CHEN H, KOPITTKE P M, et al. Cadmium contamination in agricultural soils of China and the impact on food safety[J]. Environmental Pollution, 2019, 249: 1038-1048. doi: 10.1016/j.envpol.2019.03.063 CrossRef Google Scholar Pub Med
[4]	ZHANG S, CUI M, CHEN J, et al. Modification of synthetic zeolite X by thiourea and its adsorption for Cd (II)[J]. Materials Letters, 2019, 236: 233-235. doi: 10.1016/j.matlet.2018.10.100 CrossRef Google Scholar Pub Med
[5]	YAP M W, MUBARAK N M, SAHU J N, et al. Microwave induced synthesis of magnetic biochar from agricultural biomass for removal of lead and cadmium from wastewater[J]. Journal of Industrial and Engineering Chemistry, 2017, 45: 287-295. doi: 10.1016/j.jiec.2016.09.036 CrossRef Google Scholar Pub Med
[6]	ZHANG Y, CAO B, ZHAO L, et al. Biochar-supported reduced graphene oxide composite for adsorption and coadsorption of atrazine and lead ions[J]. Applied Surface Science, 2018, 427: 147-155. doi: 10.1016/j.apsusc.2017.07.237 CrossRef Google Scholar Pub Med
[7]	HAN C, WANG M, REN Y, et al. Characterization of pruned tea branch biochar and the mechanisms underlying its adsorption for cadmium in aqueous solution[J]. RSC Advances, 2021, 11(43): 26832-26843. doi: 10.1039/D1RA04235A CrossRef Google Scholar Pub Med
[8]	ZHANG G, QU J, LIU H, et al. CuFe2O4/activated carbon composite: a novel magnetic adsorbent for the removal of acid orange II and catalytic regeneration[J]. Chemosphere, 2007, 68(6): 1058-1066. doi: 10.1016/j.chemosphere.2007.01.081 CrossRef Google Scholar Pub Med
[9]	KARUNANAYAKE A G, TODD O A, CROWLEY M, et al. Lead and cadmium remediation using magnetized and nonmagnetized biochar from Douglas fir[J]. Chemical Engineering Journal, 2018, 331: 480-491. doi: 10.1016/j.cej.2017.08.124 CrossRef Google Scholar Pub Med
[10]	LI S, LI S, WEN N, et al. Highly effective removal of lead and cadmium ions from wastewater by bifunctional magnetic mesoporous silica[J]. Separation and Purification Technology, 2021, 265: 118341. doi: 10.1016/j.seppur.2021.118341 CrossRef Google Scholar Pub Med
[11]	WANG S, ZHAO M, ZHOU M, et al. Biomass facilitated phase transformation of natural hematite at high temperatures and sorption of Cd2+ and Cu2+[J]. Environment International, 2019, 124: 473-481. doi: 10.1016/j.envint.2019.01.004 CrossRef Google Scholar Pub Med
[12]	WANG Q, LAI Z, MU J, et al. Converting industrial waste cork to biochar as Cu (II) adsorbent via slow pyrolysis[J]. Waste Management, 2020, 105: 102-109. doi: 10.1016/j.wasman.2020.01.041 CrossRef Google Scholar Pub Med
[13]	LIANG X, XIAO J, WENG W, et al. Electrochemical reduction of carbon dioxide and iron oxide in molten salts to Fe/Fe3C modified carbon for electrocatalytic oxygen evolution[J]. Angewandte Chemie International Edition, 2021, 60(4): 2120-2124. doi: 10.1002/anie.202013257 CrossRef Google Scholar Pub Med
[14]	Al-WABEL M I, Al-OMRAN A, El-NAGGAR A H, et al. Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes[J]. Bioresource Technology, 2013, 131: 374-379. doi: 10.1016/j.biortech.2012.12.165 CrossRef Google Scholar Pub Med
[15]	RAFIQ M K, BACHMANN R T, RAFIQ M T, et al. Influence of pyrolysis temperature on physico-chemical properties of corn stover (Zea mays L. ) biochar and feasibility for carbon capture and energy balance[J]. PloS one, 2016, 11(6): e0156894. doi: 10.1371/journal.pone.0156894 CrossRef Google Scholar Pub Med
[16]	FAN G, JIANG Y, XIN J, et al. Facile synthesis of Fe@ Fe3C/C nanocomposites derived from bulrush for excellent electromagnetic wave-absorbing properties[J]. ACS Sustainable Chemistry & Engineering, 2019, 7(23): 18765-18774. Google Scholar Pub Med
[17]	TOMCZYK A, SOKOLOWSKA Z, BOGUTA P. Biochar physicochemical properties: pyrolysis temperature and feedstock kind effects[J]. Reviews in Environmental Science and Biotechnology, 2020, 19(1): 191-215. doi: 10.1007/s11157-020-09523-3 CrossRef Google Scholar Pub Med
[18]	孙俊芝, 王静霞, 倪茂君, 等. 改性海藻酸钠微球对Pb吸附性能的研究[J]. 环境科学与技术, 2019(7): 6. Google Scholar Pub Med
[19]	KHAN Z H, GAO M, QIU W, et al. Mechanisms for cadmium adsorption by magnetic biochar composites in an aqueous solution[J]. Chemosphere, 2020, 246: 125701. doi: 10.1016/j.chemosphere.2019.125701 CrossRef Google Scholar Pub Med
[20]	KAKAVANDI B, JONIDI JAFARI A, REZAEI KALANTARY R, et al. Simultaneous adsorption of lead and aniline onto magnetically recoverable carbon: Optimization, modeling and mechanism[J]. Journal of Chemical Technology & Biotechnology, 2016, 91(12): 3000-3010. Google Scholar Pub Med
[21]	AHMADI M, FOLADIVANDA M, JAAFARZADEH N, et al. Synthesis of chitosan zero-valent iron nanoparticles-supported for cadmium removal: characterization, optimization and modeling approach[J]. Journal of Water Supply:Research and Technology—Aqua, 2017, 66(2): 116-130. doi: 10.2166/aqua.2017.027 CrossRef Google Scholar Pub Med
[22]	HUANG P, YE Z, XIE W, et al. Rapid magnetic removal of aqueous heavy metals and their relevant mechanisms using nanoscale zero valent iron (nZVI) particles[J]. Water Research, 2013, 47(12): 4050-4058. doi: 10.1016/j.watres.2013.01.054 CrossRef Google Scholar Pub Med
[23]	KAKAVANDI B, KALANTARY R R, JAFARI A J, et al. Pb (II) adsorption onto a magnetic composite of activated carbon and superparamagnetic Fe3O4 nanoparticles: experimental and modeling study[J]. CLEAN–Soil, Air, Water, 2015, 43(8): 1157-1166. doi: 10.1002/clen.201400568 CrossRef Google Scholar Pub Med
[24]	TANG L, FENG H, TANG J, et al. Treatment of arsenic in acid wastewater and river sediment by Fe@ Fe2O3 nanobunches: The effect of environmental conditions and reaction mechanism[J]. Water research, 2017, 117: 175-186. doi: 10.1016/j.watres.2017.03.059 CrossRef Google Scholar Pub Med
[25]	LIU K, LI F, CUI J, et al. Simultaneous removal of Cd (II) and As (III) by graphene-like biochar-supported zero-valent iron from irrigation waters under aerobic conditions: synergistic effects and mechanisms[J]. Journal of Hazardous Materials, 2020, 395: 122623. doi: 10.1016/j.jhazmat.2020.122623 CrossRef Google Scholar Pub Med
[26]	LV X, HU Y, TANG J, et al. Effects of co-existing ions and natural organic matter on removal of chromium (VI) from aqueous solution by nanoscale zero valent iron (nZVI)-Fe3O4 nanocomposites[J]. Chemical Engineering Journal, 2013, 218: 55-64. doi: 10.1016/j.cej.2012.12.026 CrossRef Google Scholar Pub Med
[27]	MAK M S H, RAO P, LO I M C. Effects of hardness and alkalinity on the removal of arsenic (V) from humic acid-deficient and humic acid-rich groundwater by zero-valent iron[J]. Water research, 2009, 43(17): 4296-4304. doi: 10.1016/j.watres.2009.06.022 CrossRef Google Scholar Pub Med
[28]	TANBOONCHUY V, GRISDANURAK N, LIAO C H. Background species effect on aqueous arsenic removal by nano zero-valent iron using fractional factorial design[J]. Journal of hazardous materials, 2012, 205: 40-46. Google Scholar Pub Med
[29]	TYROVOLA K, NIKOLAIDIS N P, VERANIS N, et al. Arsenic removal from geothermal waters with zero-valent iron—effect of temperature, phosphate and nitrate[J]. Water Research, 2006, 40(12): 2375-2386. doi: 10.1016/j.watres.2006.04.006 CrossRef Google Scholar Pub Med
[30]	LIU R, LIU F, HU C, et al. Simultaneous removal of Cd (II) and Sb (V) by Fe–Mn binary oxide: Positive effects of Cd (II) on Sb (V) adsorption[J]. Journal of hazardous materials, 2015, 300: 847-854. doi: 10.1016/j.jhazmat.2015.08.020 CrossRef Google Scholar Pub Med
[31]	GROSVENOR A P, KOBE B A, BIESINGER M C, et al. Investigation of multiplet splitting of Fe 2p XPS spectra and bonding in iron compounds[J]. Surface and Interface Analysis:An International Journal devoted to the development and application of techniques for the analysis of surfaces, interfaces and thin films, 2004, 36(12): 1564-1574. Google Scholar Pub Med
[32]	HU Y, JENSEN J O, ZHANG W, et al. Hollow spheres of iron carbide nanoparticles encased in graphitic layers as oxygen reduction catalysts[J]. Angewandte Chemie, 2014, 126(14): 3749-3753. doi: 10.1002/ange.201400358 CrossRef Google Scholar Pub Med
[33]	LI J, LAN H, LIU H, et al. Intercalation of nanosized Fe3C in iron/carbon to construct multifunctional interface with reduction, catalysis, corrosion resistance, and immobilization capabilities[J]. ACS applied materials & interfaces, 2019, 11(17): 15709-15717. Google Scholar Pub Med
[34]	MISHRA D, FARRELL J. Understanding nitrate reactions with zerovalent iron using tafel analysis and electrochemical impedance spectroscopy[J]. Environmental science & technology, 2005, 39(2): 645-650. Google Scholar Pub Med
[35]	ZHU S, ZHAO J, ZHAO N, et al. Goethite modified biochar as a multifunctional amendment for cationic Cd (II), anionic As (III), roxarsone, and phosphorus in soil and water[J]. Journal of Cleaner Production, 2020, 247: 119579. doi: 10.1016/j.jclepro.2019.119579 CrossRef Google Scholar Pub Med
[36]	WAN S, YU C, LI Y, et al. Highly selective and ultrafast removal of cadmium and copper from water by magnetic core-shell microsphere[J]. Chemical Engineering Journal, 2021, 405: 126576. doi: 10.1016/j.cej.2020.126576 CrossRef Google Scholar Pub Med
[37]	LIU C M, DIAO Z H, HUO W Y, et al. Simultaneous removal of Cu²⁺ and bisphenol A by a novel biochar-supported zero valent iron from aqueous solution: Synthesis, reactivity and mechanism[J]. Environmental pollution, 2018, 239: 698-705. doi: 10.1016/j.envpol.2018.04.084 CrossRef Google Scholar Pub Med

Access History

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142

Figures(5) / Tables(2)

Export Citation

PDF

XML

Article Metrics

Article views(2893) PDF downloads(130) Cited by(0)

Access History

HTML

由于矿山开采、金属冶炼^[1]、不合格农药使用等人类生产活动而导致大量含有重金属的废水进入自然环境，已造成严重的土壤和地下水污染^[2]。根据2014年原环境保护部与原国土资源部联合发布的全国土壤污染调查公报，我国污水灌溉区超标点位占26.4%，重金属元素镉(Cd)的超标率位列第一。而且，Cd具有不能被分解或降解的特性，对环境中的生物体表现不同程度的毒性，会通过食物链进行传递，严重威胁人类身体健康^[3]。

近年来，已有多种物理和化学技术应用于水体中Cd(Ⅱ)的污染修复，其中包括化学沉淀、离子交换、膜分离和吸附^[4]。在这些方法中，吸附方法因其能高效固定水体中的重金属且操作简单而被广泛应用。目前，已有多种吸附材料已经被用于水体中Cd(Ⅱ)的污染修复，包括活性炭、沸石、生物炭等^[5]。有研究表明，生物炭因其具有高比表面积、高阳离子交换容量(CEC)、丰富的含氧官能团和高矿物质含量，能够将Cd(Ⅱ)吸附在其表面，成为Cd(Ⅱ)污染修复应用中的有效吸附剂^[6]。HAN等利用生物炭吸附水体Cd(Ⅱ)，其最大吸附量为74.04 mg·g^−1[7]。然而，传统生物炭存在对Cd(Ⅱ)的吸附效果不理想，难以分离和回收重金属资源，并且容易引起二次污染等问题^[8]，因而限制了其在水污染修复中的应用。有研究表明，铁改性生物炭不仅可以增强Cd(Ⅱ)的吸附能力，而且可磁性回收^[9]。纳米零价铁(nZVI)因其粒径小、表面积大、活性强，在反应过程中产生的铁氧化物能够高效吸附Cd(Ⅱ)^[10]，被广泛应用于生物炭改性吸附剂。然而，之前研究中通过化学还原方法制备的nZVI改性生物炭存在易氧化和抗干扰性不足，还原剂成本高等问题，故难以广泛应用。因此，如何研发出既能高效吸附Cd(Ⅱ)，同时抗干扰能力强，且可以回收的铁炭复合材料是当前Cd(Ⅱ)污染修复的关键和难点。

综上所述，本研究使用废弃木屑生物质和铁盐为原料，使用碳热厌氧还原方法制备出一种新型多孔生物质铁炭基功能材料，并采用多种固相技术对材料的组成、结构和性质进行了表征和分析；研究了材料对水体Cd(Ⅱ)的吸附效果及其构效关系，考察了pH和干扰离子等对Cd(Ⅱ)吸附的影响；揭示了新型多孔生物质铁炭基功能材料对Cd(Ⅱ)的固定机制。

1. 材料与方法

1.1. 实验试剂

氢氧化钠、无水亚硫酸钠、氯化镉、乙醇、30%过氧化氢等化学试剂均为分析纯(广州化学试剂厂)，九水硝酸铁(分析纯)购自上海阿拉丁生化科技有限公司(中国上海)。所有实验均使用超纯水(18 MΩ·cm⁻¹)。

1.2. 材料制备

将废弃的球状天然毫米木球浸泡在NaOH和Na₂SO₃的混合溶液中，超声30 min后转移到反应釜中，并在100 ℃中反应10 h。反应后将木球取出，用超纯水冲洗，然后转移到反应釜中并加入H₂O₂，加热至100 ℃，继续保持6 h，反应后冷冻干燥，所得生物质简称为MC。将MC浸泡在Fe(NO₃)₃·9H₂O溶液中，持续振荡10 h，使得Fe³⁺充分吸附在MC上。最后置于氮气保护的真空管式炉中，分别在热解温度为400、600、800 ℃条件下保持1 h，升温速率为10 ℃·min⁻¹。制备出新型多孔生物质铁炭基功能材料，分别简称为MCFe-400、MCFe-600、MCFe-800。其中，将MC置于氮气保护的真空管式炉中在热解温度为800 ℃，其他条件与制备无铁负载的生物炭材料(BC)相同。

1.3. 材料表征

扫描电子显微镜(SU8220，HIT ACHI，日本)用于分析MCFe的形貌。比表面积和孔隙分析仪(Tristar II 3020 M，Micromeritics，美国)用于分析MCFe的比表面积和孔容。此外，使用Smartlab X射线衍射仪在2θ为10~90°(9 kW)内使用Cu靶测量反应前后样品的X射线衍射。X射线光电子能谱(ESCALAB 250Xi，Thermo Fischer，美国)用于对反应前后MCFe表面元素组成和价态进行表征。振动样品磁强计仪(PPMS-9，Quantum Design，美国)用于表征MCFe的磁滞回线。

1.4. 吸附实验

使用不同热解温度制备的MCFe和生物炭(MCFe-400、MCFe-600、MCFe-800、BC)进行动力学实验，以研究材料对水体Cd(Ⅱ)的吸附性能。实验材料的投加量为0.8 g·L⁻¹；Cd(Ⅱ)的初始质量浓度为10 mg·L⁻¹；反应体系为40 mL。所有批次实验均在50 mL离心管中进行(200 r·min⁻¹，(25±1) ℃)。反应一段时间(0、5、15、30、60、90、120、240、360 min)后，取反应混合液过0.22 μm的滤膜，用于Cd(Ⅱ)质量浓度的测定。所有实验均设置3组平行。

为探究MCFe对Cd(Ⅱ)的吸附行为，采用伪二级动力学模型(式(1))对实验数据进行拟合。采用Langmuir(式(2))和Freundlich(式(4))模型对实验结果进行拟合^[11]。

式中：q_t和q_e分别是在平衡和t时刻的吸附量，mg·g⁻¹；k₂是吸附速率常数，g·(mg·min)⁻¹。

式中：q_e为吸附达到平衡时的吸附量，mg·g⁻¹；Q_m为最大吸附量，mg·g⁻¹；C_e为平衡时溶液中污染物的质量浓度，mg·L⁻¹；K_L为Langmuir模型中结合位点的附着性相关吸附平衡常数，L·mg⁻¹；K_F为Freundlich吸附平衡常数；n为非均质性因子。

本研究考察了pH和共存的阳离子或阴离子对吸附效果的影响。实验的初始条件同上。使用HCl (0.1 mol·L⁻¹)和NaOH (0.1 mol·L⁻¹)将水溶液的初始pH调至4、6、7、9，反应6 h后测定反应体系中Cd(Ⅱ)的质量浓度。此外，磷酸根(PO₄^3-)、硫酸根(SO₄^2-)、碳酸氢根(CO₃^2-)、硝酸根(NO₃⁻)、钙离子(Ca²⁺)和镁离子(Mg²⁺)为水体终常见的阴阳离子，研究其对MCFe吸附效果的影响。

研究MCFe-800对实际水体中Cd(Ⅱ)的吸附效果。选用湖泊水、农田灌溉水和河水配制初始质量浓度为10 mg·L⁻¹的Cd(Ⅱ)溶液，用于循环吸附实验，其他实验条件同上。反应1 h后，将MCFe-800从溶液中分离出来，加入准备好的40 mL溶液中，重复4次。在带有恒温水浴夹套的层析柱(长100 mm，直径10 mm)中进行实验。每根柱子填满MCFe-800。将含有1 000 µg·L⁻¹和2 000 µg·L⁻¹ Cd(Ⅱ)的农田灌溉水(pH=7.15±0.2)由蠕动泵(LongerPump，中国)以2 mL·min⁻¹的恒定流速自下而上模式连续送入层析柱，空床接触时间(EBCT)为4 min。在预设时间收集流出溶液样品，并分析Cd(Ⅱ)的质量浓度以确定吸附效率。

1.5. 分析方法

采用电感耦合等离子体发射光谱仪(ICP-OES)测定Cd(Ⅱ)的质量浓度。将材料分散到不同pH的溶液中，超声至充分分散的悬浊液，使用Zeta电位仪测定材料表面在不同pH条件下的电位。将不同材料负载在工作电极上，然后浸入0.1 mol·L⁻¹ KCl溶液中在CHI-920d电化学工作站上进行腐蚀电流测定。

3. 结论

1)对本研究制备的新型多孔生物质铁炭基功能材料的表征结果表明，随者热解温度升高，MCFe比表面积和孔容增加，在800℃制备的MCFe-800材料表面为分散均匀的纳米零价铁颗粒;磁滞回线表明，MCFe-800的磁性最强，更容易实现固液分离。

2) MCFe-800对水体Cd(Ⅱ)的去除率明显高于其他热解温度，符合伪二级动力学，并且根据Langmuir等温线模型，MCFe对Cd(Ⅱ)的最大吸附量高达463.84 mg·g⁻¹。当pH为6~7时，其对Cd(Ⅱ)的吸附效果最佳，高浓度的CO₃^2-和PO₄^3-会抑制材料对Cd(Ⅱ)的吸附。MCFe800固定Cd(Ⅱ)的主要机制有静电吸附、共沉淀和表面络合。

3) MCFe-800对Cd(Ⅱ)的吸附具有较强的抗干扰能力，还能实现多次循环。滤柱实验结果显示，该材料能够将农田灌溉水中1 000 μg·L⁻¹和2 000 μg·L⁻¹的Cd(Ⅱ)快速降低至饮用水标准，其有效处理量分别为400 BV和270 BV。

Figure (5) Table (2) Reference (37)

Novel biomass-derived porous iron/carbon materials for highly efficient cadmium removal and its mechanisms