共查询到18条相似文献,搜索用时 109 毫秒
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以海南椰树壳为原料通过复合物理活化方法制备出2162.84m2/g的高比表面积活性炭,所得活性炭孔径分布范围为1.1-2.5nm.选择对曙红Y染料进行吸附研究,采用分光光度法考查吸附剂用量、pH值、初始浓度、温度与吸附时间对单组分体系染料的吸附量与脱除效果的影响.结果表明在曙红Y浓度1600g ·m-3、pH为2.02、吸附时间10min、温度318K和吸附剂用量0.05g时脱除率可达99.9%. 相似文献
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壳聚糖的吸附行为及其FTIR光谱研究 总被引:12,自引:1,他引:11
用自制的壳聚糖对几种酸性染料和碱性染料模拟废水进行了吸附行为的研究,考察了吸附时间、壳聚糖脱已酰度及废水pH值对吸附效果的影响。研究表明,在吸附开始的20 min内,壳聚糖对碱性品红和番红花红的吸附已基本达到平衡,且用量只为活性炭用量的2/3的情况下,对染料的吸附效果与活性炭几乎相当;它对酸性大红的吸附过程呈现一级反应动力学特征。文章还采用傅里叶变换红外光谱对壳聚糖吸附染料的机理进行了探讨,研究发现,壳聚糖分子中存在的大量羟基参与了对碱性品红和番红花红的吸附。 相似文献
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研究了复合蛋白酶对云南土著白鱼水解的工艺条件。考察了酶用量、温度、pH值、反应时间、底物浓度、复合酶比例等因素对白鱼水解的影响。确定了最佳酶解条件为:复合酶用量(木瓜蛋白酶+风味蛋白酶1∶1)16000U/g,底物浓度30%,温度55℃,pH值7.5,时间4h。在此条件下,水解度达34.12%,氮回收率90.05%。该结果为云南白鱼生产功能食品提供科学依据。 相似文献
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Yanhui Li Qiuju DuTonghao Liu Yan QiPan Zhang Zonghua WangYanzhi Xia 《Applied Surface Science》2011,257(24):10621-10627
Enteromorpha prolifera was pyrolyzed to prepare activated carbon using chemical activation by zinc chloride. The effect of activation parameters such as activation temperature, weight ratio (Enteromorpha prolifera to ZnCl2), and activation time was investigated. The BET results showed that the surface area and pore volume of activated carbons were achieved as high as 1722 m2/g and 1.11 cm3/g, respectively, in the optimal activation conditions. Batch adsorption studies were carried out to study the adsorption properties of cationic red X-GRL onto activated carbon by varying the parameters like initial solution pH, contact time, and temperature. The kinetic studies showed that the adsorption data followed a pseudo second-order model. The isotherm analysis indicated that the adsorption data could be represented by the Langmuir isotherm model. The Langmuir monolayer adsorption capacity of cationic red X-GRL was estimated as 263.16 mg/g at pH 6.0. 相似文献
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重金属污染是一个相当严重的环境问题。镉具有很强的生物毒性和不可降解性,对生态环境和人体健康有极大威胁,被列为优先控制污染物。环境中镉的主要污染源是电镀、采矿和化学工业等部门的废水,如何简单高效去除水中的镉,有重要的社会意义和经济意义。目前,水中重金属的去除方法有化学沉淀、膜分离、离子交换、吸附、电解等,其中吸附法因简单高效而广泛应用。活性炭纤维是一种新型活性炭,孔径小且均匀,表面官能团发达,吸附性能好,逐步应用于水处理领域。以电感耦合等离子体光谱为检测手段,佐以比表面积分析,X射线衍射,元素分析和傅里叶变换红外光谱,研究比较了三种活性炭纤维(纤维炭网、活性炭无纺布、活性炭纤维毡)的结构特点及其对水中镉的吸附性能。三种活性炭纤维结构基本类似,具有较发达的孔隙结构。活性炭无纺布极性较强,表面有丰富的羟基、羧基、醛基等含氧官能团,对水中镉的吸附作用最大。因此,选择活性炭无纺布为吸附剂进行后续实验。研究了活性炭无纺布吸附镉的影响因素,如溶液pH,吸附时间等。溶液pH影响吸附剂表面电荷及水中镉的存在状态。水中镉的去除效率随溶液初始pH的增大而增大,在较低pH时,吸附剂与Cd2+间存在静电斥力,同时H+和Cd2+存在竞争吸附,pH>9时,镉的去除是吸附与沉淀协同作用的结果,选择pH为6~7。在吸附的初始阶段,活性炭无纺布对Cd2+的吸附量迅速增加,10 min时,吸附率达到72%。随着吸附位点逐渐被Cd2+所填充,吸附速率逐渐变慢,300 min时,吸附容量基本无变化,吸附趋于平衡。优化了镉的吸附条件后,进行等温吸附实验和动力学实验。结果表明,25 ℃时,吸附时间为300 min,pH 6.0条件下,当镉的平衡浓度在20.00 mg·L-1时,活性炭无纺布对镉的单位质量吸附量和单位比表面积吸附量分别是3.04 mg·g-1和0.035 mg·m-2。用Langmuir方程(R2=0.997, KL =1.796 L·mg-1)和Freundich方程(R2=0.895, KF=0.918 L·mg-1, n=2.12)拟合活性炭无纺布对镉的等温吸附数据,Langmuir方程计算的理论吸附量为3.07 mg·g-1,与实验值相当,并且线性系数更高,说明该体系的吸附符合Langmuir方程,主要为单分子层吸附。Langmuir分离因子介于0和1之间,表明活性炭无纺布对镉的吸附容易进行。用准一级动力学方程、准二级动力学方程、颗粒内扩散方程和Elovich方程四种动力学模型拟合吸附过程。在吸附的前5 min,镉在活性炭无纺布上的吸附符合颗粒内扩散方程(R2=0.985),吸附主要受颗粒内扩散控制。在吸附的5~300 min,颗粒内扩散方程拟合较差。整个吸附过程符合准二级动力学方程(R2=0.999,k2=0.367 g·mg-1·min-1),Elovich方程(R2=0.981,a=0.271 mg·g-1, b=0.083 mg·g-1·(lg min)-1)和准一级动力学方程(R2=0.927,k1=0.008 8 min-1)次之,颗粒内扩散方程(R2=0.785)最差。活性炭无纺布对镉的吸附过程是一种化学作用为主的吸附过程。对5.00 mg·L-1含镉水样,活性炭无纺布投放量为10 g·L-1时,吸附后水中镉的浓度小于0.10 mg·L-1,符合《污水综合排放标准》(GB 8978-1996)。活性炭无纺布可同时吸附镉,铜,铅,铬等重金属离子,选择性较差。但在电镀、采矿等实际废水中重金属种类复杂,适当提高吸附剂投放量,可同时去除多种重金属。利用活性炭无纺布吸附处理含镉水样,处理效果好、操作简单,可以作为去除水中镉的吸附剂,为含镉废水的处理提供了技术支持和理论基础。 相似文献
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M. Ghaedi S. Haghdoust S. Nasiri Kokhdan A. Mihandoost R. Sahraie A. Daneshfar 《光谱学快报》2013,46(7):500-510
Activated carbon (AC), multiwalled carbon nanotube (MWCNT), and cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)2-NW-AC) have been used for the removal of safranine O (SO) from wastewater. The effects of various parameters including pH, temperature, concentration of the dye, amount of adsorbents, and contact time on the SO adsorption efficiency for all adsorbents has been investigated. Graphical correlation of fitting experimental data to various adsorption isotherm models like those of Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich for all adsorbents have been calculated. It was found that safranine O adsorption on all adsorbents was endothermic and feasible in nature. Fitting the experimental data to different kinetic models suggests that the adsorption process follows pseudo-second-order kinetics with involvement of the particle diffusion mechanism. 相似文献
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An optimization study using response surface methods on the decolorization of Reactive Blue 19 from aqueous solution by ultrasound 总被引:1,自引:0,他引:1
The decolorization of reactive dye C.I. Reactive Blue 19 from aqueous solution was studied by using ultrasound, activated carbon and combined ultrasound/activated carbon. The combined effects of independent variables, such as ultrasound power, temperature, time, activated carbon concentration, dye concentration and initial pH were investigated on the decolorization by using the central composite design. The decolorization of RB 19 was modelled statistically and optimized by means of the Matlab computer software. The decolorization were accomplished at optimum conditions by using ultrasound, activated carbon and combined ultrasound/activated carbon as 36%, 91% and 99.9%, respectively. The application of ultrasonic irradiation was found to be beneficial for decolorization of RB 19 from aqueous solution by adsorption. 相似文献
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S. Erdo?an C. Akmil-Ba?ar Ç. Sar?c?-Özdemir G. ?çduygu 《Applied Surface Science》2005,252(5):1324-1331
Waste apricot supplied by Malatya apricot plant (Turkey) was activated by using chemical activation method and K2CO3 was chosen for this purpose. Activation temperature was varied over the temperature range of 400-900 °C and N2 atmosphere was used with 10 °C/min heat rate. The maximum surface area (1214 m2/g) and micropore volume (0.355 cm3/g) were obtained at 900 °C, but activated carbon was predominantly microporous at 700 °C. The resulting activated carbons were used for removal of Ni(II) ions from aqueous solution and adsorption properties have been investigated under various conditions such as pH, activation temperature, adsorbent dosage and nickel concentration. Adsorption parameters were determined by using Langmuir model. Optimal condition was determined as; pH 5, 0.7 g/10 ml adsorbent dosage, 10 mg/l Ni(II) concentration and 60 min contact time. The results indicate that the effective uptake of Ni(II) ions was obtained by activating the carbon at 900 °C. 相似文献
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采用Fenton试剂对模拟染料废水的降解效果进行研究。结果表明,H2O2投加量、Fe2+投加量、pH值条件、超声处理时间的改变对染料废水的处理效果影响很大。对酸性染料:当pH为4.5,30%H2O2投加的体积分数为30mL/L,Fe2+投加的质量浓度为400mg/L,反应时间为40min时为降解反应的最佳操作条件。对碱性染料,正交试验表明当pH为4、30%H2O2投加的体积分数16mL/L、Fe2+投加的质量浓度为300mg/L、反应时间为60min时为降解反应的最佳操作条件,其降解率达98.46%,COD的去除率达到96.7%。 相似文献
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M. S. Podder 《Composite Interfaces》2016,23(4):327-372
The granular activated carbon/MnFe2O4 composite with a mass ratio of 2:1 was synthesized using a simple chemical coprecipitation procedure and used for the removal of As(III) and As(V) from synthetically prepared wastewater. Physicochemical analysis of the composite was carried out through Brunauer, Emmett and Teller surface area and total pore volume, Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Micrograph and Energy-Dispersive X-Ray Spectroscopy (SEM-EDX). The impact of various adsorption parameters such as the initial pH, adsorbent dose, contact time, temperature and initial arsenic concentration were systematically investigated to evaluate the optimum operating conditions. Nonlinear regression analysis was employed to identify the best-fit isotherm on the basis of three correlation coefficients and three error functions and also to predict the parameters involved in one one-parameter, six two-parameter, nineteen three-parameter, three four-parameter and one five-parameter isotherms. The maximum adsorption capacities estimated using the Langmuir model were 1253 mg/g for As(III) and 1314 mg/g for As(V) at 30 °C temperature and 70 min contact time. The results showed that As(III) and As(V) removal was strongly pH-dependent with an optimum pH value of 7.0 and 4.0, respectively. The mean adsorption energy (E) calculated from the D–R model indicated the nature of adsorption being ion exchange type. 相似文献
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Activated carbon (AC) has been widely used in water treatment because of its rich pore structure, large specific surface area, simple production process, low preparation cost and wide source of raw materials. In this paper, the regeneration efficiency of low-frequency ultrasonic pretreatment (40 kHz, 115Μw/cm3) on biological activated carbon (BAC) is investigated, and its principle is discussed. The results show that the micro-jet and micro-liquid flow with high temperature and pressure produced by micro-bubble rupture during ultrasonic cavitation play an important role in the regeneration of activated carbon. And optimum ultrasonic treatment time is determined (5 min). In addition, the preparation of cu-loaded activated carbon by ultrasound-microwave method is investigated to pretreat wastewater produced in paracetamol production. The results show that Cu and Cu oxides can be loaded on activated carbon surface by ultrasonic-microwave pretreatment. Finally, the pretreatments of activated carbon by physical, chemical and physical–chemical method are investigated. The effects of the above different pretreatment methods on the structure and adsorption properties of activated carbon are compared and evaluated 相似文献