不同热解条件下制备的秸秆炭对铜离子的吸附动力学
Adsorption kinetics of copper ion on straw biochars prepared under different pyrolysis condition
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摘要: 研究了不同热解条件下制备的秸秆生物炭对铜离子的吸附动力学规律.以常见的玉米杆和番茄杆为原料,在限氧升温热解的条件下制备生物炭.研究不同热解温度(300、400、500、600、700℃)和不同热解时间(1、2、4、6、8 h)对秸秆生物炭吸附性能的影响,实验结果表明番茄杆样品T6004和玉米杆样品C6006分别获得对铜离子的最佳吸附效果,其去除率分别为98.40%和98.77%.通过批试验探明秸秆生物炭对Cu2+的吸附动力学特征与机理,秸秆生物炭对Cu2+的吸附动力学数据随时间的变化能很好地用准二级动力学方程进行拟合,说明生物炭对Cu2+的吸附是一个复杂的过程,并不是简单的单层吸附.用颗粒内扩散模型进行拟合分析发现,热解时间和温度对秸秆生物炭的吸附边界层厚度均会产生不同程度的影响.此外,颗粒内扩散并非吸附过程的唯一控速步骤,表面吸附和液膜扩散共同控制吸附反应速率.Abstract: This paper aims to investigate the adsorption kinetic for copper ions on biochars prepared under different conditions. A series of biochars from tomato stem and cornstalk were synthesized at different temperatures (300, 400, 500, 600, 700℃) or different pyrolytic times (1, 2, 4, 6, 8 h) under limited oxygen condition. The sample T6004 and C6006 possess optimum absorption capacity for copper ions, and the removal rates were 98.40% and 98.77% respectively. The adsorption kinetic features of the biochars could be best fitted by pseudo second-order kinetic model regardless of pyrolysis condition, suggesting that the adsorption is related to the adsorption sites on biochar, rather than simple single-layer sorption. The results of intraparticle diffusion model indicated that the adsorption boundary layers are influenced by different pyrolysis temperatures and times. The fitting analyses using the intraparticle diffusion model also showed that the adsorption process was effected by intraparticle diffusion, surface adsorption and liquid film diffusion.
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Key words:
- straw /
- biochar /
- pyrolysis /
- copper ion /
- adsorption kinetics
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[1] CHEN B,ZHOU D,ZHU L. Transitional adsorption and partition of nonpolar and polar aromatic contaminants by biochars of pine needles with different pyrolytic temperatures[J]. Environmental Science & Technology,2008,42(14): 5137-5143. [2] LEHMANN J,JOSEPH S.Biochar for environmental management: Science and technology[M]. London,UK:Earthscan, 2009. [3] YANG G X,JIANG H. Amino modification of biochar for enhanced adsorption of copper ions from synthetic wastewater[J]. Water Research,2014,48: 396-405. [4] ZHANG W,MAO S,CHEN H,et al. Pb(Ⅱ) and Cr(Ⅵ) sorption by biochars pyrolyzed from the municipal wastewater sludge under different heating conditions[J]. Bioresource Technology,2013,147: 545-552. [5] ZHAO X,OUYANG W,HAO F,et al. Properties comparison of biochars from corn straw with different pretreatment and sorption behaviour of atrazine[J]. Bioresource Technology,2013,147: 338-344. [6] HALE S E,ALLING V,MARTINSEN V,et al. The sorption and desorption of phosphate-P,ammonium-N and nitrate-N in cacao shell and corn cob biochars[J]. Chemosphere,2013,91(11): 1612-1619. [7] 安增莉,侯艳伟,蔡超,等. 水稻秸秆生物炭对Pb(Ⅱ)的吸附特性[J]. 环境化学,2011,30(11): 1851-1857 AN Z L,HOU Y W,CAI C,et al. Lead (Ⅱ) adsorption characteristics on different biochars derived from rice straw[J]. Environmental Chemistry,2011,30(11): 1851-1857(in Chinese).
[8] XU X,CAO X,ZHAO L,et al. Removal of Cu,Zn,and Cd from aqueous solutions by the dairy manure-derived biochar[J]. Environmental Science and Pollution Research,2013,20(1): 358-368. [9] 陈宁,吴敏,许菲,等. 滇池底泥制备的生物炭对菲的吸附-解吸. 环境化学,2011,30(12): 2026-2031. CHEN N,WU M,XU F,et al. Sorption and desorption of phenanthrene in the biochar derived from DIANCHI sediment[J]. Environmental Chemistry,2011,30(12): 2026-2031(in Chinese).
[10] ZHENG H,WANG Z,DENG X,et al. Characteristics and nutrient values of biochars produced from giant reed at different temperatures[J]. Bioresource Technology,2013,130: 463-471. [11] WANG D,ZHANG W,HAO X,et al. Transport of biochar particles in saturated granular media: Effects of pyrolysis temperature and particle size[J]. Environmental Science & Technology,2013,47(2): 821-828. [12] 李坤权,王艳锦,杨美蓉,等. 多胺功能化介孔炭对Pb (Ⅱ)的吸附动力学与机制[J]. 环境科学,2014,35(8): 3198-3205. LI K Q,WANG Y J,YANG M R,et al. Adsorption kinetics and mechanism of lead (Ⅱ) on polyamine-functionalized mesoporous activated carbon[J]. Environmental Science,2014,35(8): 3198-3205(in Chinese).
[13] LAGERGREN S. About the theory of so-called adsorption of soluble substances[M]. Kungliga Svenska Vetenskapsakademiens Handlingar,1898,24(4):1-39. [14] HO Y S,MCKAY G. Pseudo-second order model for sorption processes[J]. Process biochemistry,1999,34(5): 451-465. [15] Weber W,Morris J. Proceeding of the international conference on water pollution symposium[J]. Oxford: Pergamon Press,1962,2: 235-266. [16] SEGUN ESAN O,NURUDEEN ABIOLA O,OWOYOMI O,et al. Adsorption of brilliant green onto luffa cylindrical sponge: equilibrium,kinetics,and thermodynamic studies[J]. ISRN Physical Chemistry,2014,2014. [17] CHEN B,CHEN Z,LV S. A novel magnetic biochar efficiently sorbs organic pollutants and phosphate[J]. Bioresource Technology,2011,102(2): 716-723. [18] KOłODYńSKA D,WNęTRZAK R,LEAHY J,et al. Kinetic and adsorptive characterization of biochar in metal ions removal[J]. Chemical Engineering Journal,2012,197: 295-305. [19] 徐楠楠,林大松,徐应明,等. 玉米秸秆生物炭对Cd2+的吸附特性及影响因素[J]. 农业环境科学学报,2014,(5): 958-964. XU N,LIN D S,XU Y M,et al. Adsorption of aquatic Cd2 +
by biochar obtained from corn stover[J]. Journal of Agro-environment Science,2014,(5): 958-964(in Chinese).[20] 余峻峰,陈培荣,俞志敏,等. KOH活化木屑生物炭制备活性炭及其表征[J]. 应用化学,2013,30(9): 1017-1022. YU J F,CHEN P R,YU Z M,et al. preparation and characteristic of activated carbon from sawdust biochar by chemical activation with KOH[J]. Chinese Journal of Applied Chemistry,2013,30(9): 1017-1022(in Chinese).
[21] 许端平,褚海艳,徐雪松. 褐煤对废水中酸性红B的吸附去除[J]. 环境工程学报,2012,6(6): 1961-1965. XU D P,CHU H Y,XU X S. Adsorption and removal of dye Acid Red B from wastewater by lignite[J]. Chinese Journal of Environmental Engineering,2012,6(6): 1961-1965(in Chinese).
[22] 马锋锋,赵保卫,钟金魁,等. 牛粪生物炭对磷的吸附特性及其影响因素研究[J]. 中国环境科学,2015,35(4): 1156-1163. MA F F,ZHAO B W,ZHONG J K,et al. Characteristics phosphate adsorption onto biochars derived from dairy manure and its influencing factors[J]. China Environmental Science,2015,35(4): 1156-1163(in Chinese).
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