Abstract:The fractal dimension is an important parameter of flocculation of traditional Chinese Medicine's water-extraction with chitosan. In this paper, Flocs' fractal dimension is determined by image method, and Zeta potential instrument is applied to determine the ζ potential of flocculation system, so as to explore the mechanism and effect of the flocculation. Chitosan is selected as a flocculant to purify the impurity of water-extract of peony, the flocculation's operating conditions, such as the dosage of flocculant, flocculation temperature, pH value and so on, are adjusted to explore the impact of these factors on the flocculation and the variation of flocs' fractal dimension. When the dosage is increased, the fractal dimension of flocs shows a downward trend. When the temperature or pH value is increased, the fractal dimension of flocs shows a situation that it increases firstly, then decreases. The optimum conditions of peony's water-extract is acknowledged by orthogonal experiment:flocculant dosage is 0.310 g·L-1, flocculation temperature is 30℃, pH value is 3. In this case, the flocculation flocculation rate is 94.32% when the fractal dimension is 1.430.
[1] 张建伟,范红伟.壳聚糖对银杏水提液的絮凝工艺研究[J]. 化学工程,2008,36(2):71-74. ZHANG J W,FAN H W.Study on flocculation of water-extraction solution of ginkgo leaves with chitosan[J].Chemical Engineering,2008,36(2):71-74.
[2] 张建伟,袁园,王春雨.壳聚糖对桑白皮水提液净化除杂的研究[J]. 高校化学工程学报,2010,24(2):346-349. ZHANG J W,YUAN Y,WANG C Y.Purification of water-extraction solution of mulberry root bark with chitosan[J].Journal of Chemical Engineering of Chinese Universities,2010,24(2):346-349.
[3] 张建伟,于婧超,冯颖.2种天然絮凝剂对薄荷水提液的絮凝研究和比较[J]. 浙江大学学报:理学版,2012,39(4):428-433. ZHANG J W,YU J C,FENG Y.Comparison and study of the flocculation effect of peppermint water-extraction solution by two natural flocculants[J].Journal of Zhejiang University:Science Edition,2012,39(4):428-433.
[4] 温海龙,董瑞斌,朱升干.分形维数作为废水絮凝处理效果的表征指标及其影响因素[J]. 南昌大学学报:工科版,2011,33(1):17-21. WEN H L,DONG R B,ZHU S G.Fractal dimension as a characteristic index of flocculation[J].Journal of Nanchang University:Engineering & Technology,2011,33(1):17-21.
[5] 郑典模,朱升干,蒋文天,等.基于DLCA模型的絮凝过程模拟及应用[J]. 南昌大学学报:工科版,2011,33(2):129-133. ZHENG D M,ZHU S G,JIANG W T,et al.Simulation on flocculation process based on DLCA model and its application[J].Journal of Nanchang University:Engineering & Technology,2011,33(2):129-133.
[6] MAGGI F,MIETTA F,WINTERWERP J C.Effect of variable fractal dimension on the floc size distribution of suspended cohesive sediment[J]. Journal of Hydrology,2007,343(1/2):43-55.
[7] MAERZ J,VERNEY R,WIRTZ K,et al.Modeling flocculation processes:Intercomparison of a size class-based model and a distribution-based model[J].Continental Shelf Research,2011,31(10):84-93.
[8] 李春梅,施周,梅胜,等.絮凝条件对絮体分型结构的影响[J]. 环境科学,2006,27(3):489-492. LI C M,SHI Z,MEI S,et al.Effects of flocculation conditions on aggregates fractal structures[J].Environmental Science,2006,27(3):489-492.
[9] 钟润生,张锡辉,肖峰,等.絮体分型结构对沉淀速度影响研究[J]. 环境科学,2009,30(8):2353-2357. ZHONG R S,ZHANG X H,XIAO F,et al.Effects of fractal structure on settling velocities of flocs[J]. Environmental Science,2009,30(8):2353-2357.
[10] 韦伟,杜茂安,朱佳,等.絮凝过程中絮体生长的多重分形行为[J]. 环境科学学报,2014,34(4):79-84. WEI W,DU M A,ZHU J,et al.Multifractal behavior of flocs growth in flocculation processes[J].Acta Scientiae Circumstantiae,2014,34(4):79-84.
[11] 王慧,曾令可.分形理论及其在材料科学中的应用[J]. 材料开发与应用,2010,15(5):39-43. WANG H,ZENG L K.Fractal theory and its application in materials science[J].Development and Application of Materials,2010,15(5):39-43.
[12] 成秋明.多重分形与地质统计学方法用于勘查地球化学异常空间结构和奇异性分析[J]. 地球科学,2001,26(2):161-166. CHENG Q M.Multifractal and geostatistical methods for characterizing local structure and singularity properties of exploration geochemical anomalies[J].Earth Science,2001,26(2):161-166.
[13] MEAKIN P.Fractal aggregates[J].Advances in Colloid and Interface Science,1988,28:249-331.
[14] LOGAN B E,KILPS J R.Fractal dimensions of aggregates formed in different fluid mechanical environments[J].Water Research,1995,29(3):443-453.
[15] 王晓昌,丹保宪仁.絮凝体形态学和密度的探讨-Ⅰ.从絮凝体分型构造谈起[J]. 环境科学学报,2000,20(3):257-262. WANG X C,NORIHITO T.A study on the morphology and density of flocsⅠ.The fractal structure of floc[J].Acta Scientiae Circumstantiae,2000,20(3):257-262.
[16] 李警阳,张忠国,孙春宝,等.基于分形学的絮凝理论研究进展[J]. 化工进展,2012,31(12):2609-2614. LI J Y,ZHANG Z G,SUN C B,et al.A review of flocculation theories incorporating fractal geometry[J].Chemical Industry and Engineering Progress,2012,31(12):2609-2614.
[17] 于婧超. 薄荷水提液的絮凝工艺研究[D].沈阳:沈阳化工大学,2012. YU J C. Study on Flocculation of Water-Extraction Solution of Peppermint[D].Shenyang:Shenyang University of Chemical Technology,2012.
[18] CHAKRABORTI R K,ATKINSON J F,BENSCHOTEN J E V,et al.Characterization of alum floc by image analysis[J].Environmental Science and Technology,2000,34(18):3969-3976.
[19] 卢佳,王毅力,杜白雨,等.聚合氯化铁腐殖酸(PFC-HA)絮体的粒度和分形维数的动态变化[J]. 环境科学学报,2008,28(4):624-633. LU J,WANG Y L,DU B Y,et al.Dynamic change of particle size and fractal dimensions of polyferric chloride-humic acid (PFC-HA) flocs[J].Acta Scientiae Circumstantiae,2008,28(4):624-633.
[20] 孙姣,秦莉,李桂水,等.壳聚糖对小儿咳喘灵原药提取液絮凝除杂效果研究[J]. 中草药,2013,44(2):174-179. SUN J, QIN L, LI G S, et al. Effect of chitosan on flocculation impurity removal of extract from Xiao'er Kechuanling oral liquid[J].Chinese Traditional Herbal Drugs,2013,44(2):174-179.
[21] 郑丽娜. 复合型生物絮凝剂絮凝特性及絮凝絮体分形特性研究[D].哈尔滨:哈尔滨工业大学,2007. ZHENG L N.Evaluation of the Flocculating and Fractal Characteristics of Compound Biological Flocculants[D]. Harbin:Harbin Institute of Technology,2007.
[22] 王晓昌,丹保宪仁.絮凝体形态学和密度的探讨-Ⅱ.致密性絮凝体形成操作模式[J]. 环境科学学报,2000,20(4):385-390. WANG X C, NORIHITO T. A study on the morphology and density of flocsⅡ. Operation modes for compact floc formation[J].Acta Scientiae Circumstantiae,2000,20(4):385-390.
[23] KRANENBURG C. The fractal structure of cohesive sediment aggregates[J].Estuarine Coastal and Shelf Science,1994,39(6):451-460.
[24] XIA X M, LI Y, YANG H, et al. Observations on the size and settling velocity distributions of suspended sediments in the Pearl River Estuary, China[J].Continental Shelf Research,2004,24(16):1809-1826.
[25] FOX J M, HILL P S, MILLIGAN T G, et al. Floc fraction in the waters of the Po River prodelta[J].Continental Shelf Research,2004,24(15):1699-1715.