共查询到20条相似文献，搜索用时 62 毫秒
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采用溶液插层法,利用壳聚糖和蒙脱土制备了壳聚糖/蒙脱土插层复合物,使用红外光谱和X-射线衍射分析对其结构进行了表征;以此复合物为活性红染料RR136的吸附剂,考察了复合物中壳聚糖与蒙脱土的摩尔比、染料溶液pH值和浓度、吸附温度及吸附剂用量等因素对吸附性能的影响。结果表明,吸附反应的最佳条件是以壳聚糖与蒙脱土摩尔比为5∶1的插层复合物为吸附剂,反应温度20℃,RR136溶液pH为3。壳聚糖/蒙脱土插层复合物对活性红染料的吸附更符合Langmuir模型,吸附热力学参数ΔGo、ΔHo和ΔSo值分别为-3.338kJ·mol-1(30℃),-37.98kJ·mol-1和-114.77J·mol-1·K-1,表明壳聚糖/蒙脱土插层复合物对活性红染料的吸附是自发的、以物理吸附为主的放热反应。 相似文献
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本文研究了不同pH、反应时间、温度、初始糖浓度条件下溶液中褐藻胶低聚糖（AOS）在活性炭上的吸附性能及其吸附动力学和热力学机制。结果表明，溶液pH对活性炭吸附AOS具有重要影响，随pH降低，AOS在活性炭上的吸附增强，pH=1时吸附量可达0.116 g/g。吸附反应在5 min内迅速发生，60 min后达到吸附平衡。活性炭吸附AOS符合准二级吸附动力学过程。吸附热力学研究表明，吸附过程为自发的放热反应，吸附等温线符合Langmuir模型。综上，吸附过程为单分子层均相吸附，降低pH、低温有利于AOS在活性炭上的吸附。 相似文献
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通过静态吸附实验,研究了酸碱度(pH)、两种重金属离子(Pb2+、Cd2+)单独及共同作用对棕壤吸附五氯酚(PCP)的影响。结果表明,棕壤对PCP的吸附量随溶液pH的升高而降低,且随Pb2+和Cd2+浓度的升高,吸附呈先下降后升高的趋势,Freundlich模型能较好的描述棕壤对PCP的吸附行为,吸附呈非线性。pH=4.0~5.9范围时,Pb2+促进棕壤对PCP的吸附,pH=5.9~10.0范围时,Pb2+抑制其吸附;pH=4.0~8.8范围时,Cd2+抑制棕壤对PCP的吸附,pH=8.8~10.0范围时,Cd2+促进其吸附。傅里叶变换红外光谱及紫外-可见光谱分析进一步表明,溶液中PCP与金属离子形成了复合离子(PCP-Me+),PCP-Me+的稳定常数以及金属离子和PCP的形态变化明显影响棕壤吸附PCP,离子强度的变化对PCP的吸附也有一定的影响。 相似文献
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《中国海洋大学学报(自然科学版)》2017,(8)
本文使用溶液插层法制备羧甲基壳聚糖/有机蒙脱土(CMC/OMMT)复合物。以该复合物为吸附剂,去除水中的4-氯酚(4-CP)、2,4-二氯酚(DCP)及2,4,6-三氯酚(TCP)。考察了pH值对吸附性能的影响,并对其吸附动力学和吸附热力学特征进行了研究。结果表明,CMC/OMMT吸附4-CP、DCP和TCP的最适pH值分别为9、7和5。CMC/OMMT对氯酚类化合物的吸附过程符合拟二级动力学模型,且颗粒内扩散不是吸附速率的唯一控制步骤。CMC/OMMT对氯酚类化合物的吸附平衡最符合非线性Tempkin模型。热力学参数ΔGo、ΔHo及ΔSo表明该吸附过程是以物理吸附为主的放热反应。连续进行5次吸附/再生循环后,CMC/OMMT对4-CP、DCP和TCP的再生率分别为50.50%、46.76%和51.05%,表明该复合物具有较好的重复使用潜力。 相似文献
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提要 鱿鱼(Ommastrephes bartrami)皮胶原蛋白提取液为红棕色,不利于在食品中广泛地应用。为了进一步利用鱿鱼皮胶原蛋白,本文采用活性炭吸附法脱除鱿鱼皮胶原蛋白提取液中色素,优化脱色条件。在确定该色素特征吸收波长为420 nm条件下,分别研究了活性炭添加量、脱色时间、溶液pH值和吸附温度对鱿鱼皮胶原蛋白液色素脱除效果影响。在单因素实验基础上,选择吸附时间30 min,进行活性炭添加量、溶液pH值、吸附温度三因素三水平Box-Behnken中心组合响应面分析试验。结果表明：活性炭吸附鱿鱼皮胶原蛋白液色素最佳条件为活性炭添加量4.2%,溶液pH值2.27,脱色温度35 ℃,该条件下鱿鱼皮胶原蛋白液的脱色率为45.6%,蛋白质和氨基酸损耗率分别为19.65%和22.93%。脱色后鱿鱼皮胶原蛋白的甘氨酸含量最高(136.02 mg/g,相对含量23.05%),谷氨酸、精氨酸和脯氨酸含量也较高,而半胱氨酸和蛋氨酸总量不到1%,符合水产蛋白氨基酸和I型胶原蛋白氨基酸特点。 相似文献
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莱州湾南岸地下卤水高浓度溶解铀及其成因研究 总被引：1，自引：0，他引：1
用α能谱法对莱州湾南岸地下卤水中的铀进行分析,发现卤水中溶解铀的浓度范围为3.4～96.0μg/L,80%以上站位卤水铀浓度超过了30μg/L,高于某些铀矿区地下水中铀的浓度。从卤水的形成过程及环境、含水层沉积物的铀含量及地下卤水对沉积物的淋溶作用、地表水下渗等几个方面对高浓度铀的成因进行了分析,发现卤水形成时海水的蒸发浓缩和锰氧化物还原可能是主要成因,藻类的矿化分解使其吸附的大量铀解吸进入地下水也可能是1个重要影响因素。 相似文献
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The adsorption behaviour for uranium of four kinds of amidoxime resinst RNH, RCH, RAH and RPH in seawater has been investigated. It has been found that all these resins are capable of adsorbing rapidly uranium from U-cnriched seawater with a high uranium uptake.RNH was able to adsorb uranium satisfactorily from natural seawater, and the uranium uptake of RNH with a degree of cross-linking of 3-5 mol % was above 200 μg/g-R (adsorption for 15 days). The uranium uptakes of RCH, RAH and RPH from natural seawater were much lower than the uranium uptake of RNH. The factors which caused the difference between resins RCH, RAH, RPH and resin RNH are discussed. 相似文献
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MECHANISM OF URANIUM ADSORPTION ON AMIDOXIME RESIN 总被引：1，自引：0，他引：1
The mechanism of uranium adsorption from seawater by polyacrylamidoxime resin is investigated by means of the experiments of adsorption isotherm and adsorption rate. The uranium uptake increases with the adsorption temperature and varies with the pH of seawater. Thermochemical and kinetic calculation show that the enthalpy change (△H) and the activation energy (E) of the uranium adsorption are 42.4 42.4 kJ mol-1 and 41.2 kJ mol-1 respectively, indicating that the uranium adsorption on the resin proceeds via a certain complex chemical reaction in which the amidoxime group in the resin chelates uranyl ions. 相似文献
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Through introducing amidoxime and carboxyl groups into polyacrylonitrile fiber, a fibrous adsorbent with high capacity and fast adsorption rate was obtained, which could adsorb 4.6 mg uranium/g in 10 days from natural seawater. The influence of the functional group content on equilibrium adsorption capacity Xm and adsorption rate constant K of the adsorbent was studied, thus indicating that the contents of amidoxime and carboxyl groups correlated with Xm and K respectively. It is concluded that the amidoxime group is of reactive adsorption, while the carboxyl group is of promotion in the adsorption of uranium. In this paper, the mechanism of uranium adsorption on the fibrous adsorbent is deduced and the chelating structure of adsorption species is discussed with molecule orbit theory. 相似文献
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1. The adsorption action of basic zinc carbonate adsorbent on uranium in natural seawater can be expressed with the following formula of adsorption isotherm:C=k(U*)n = 8.51× 10-1(U*)0.49,where C is the concentration of uranium on adsorbent; U* is content of uranium in natural seawater employed.2. when the quantity of basic zinc carbonate adsorbent (T) is constant, with the increase of natural seawater quantity through the adsorption column (G), also increased are the adsorption content of uranium of the adsorbent (U), the concentration of uranium on the adsorbent (C) and the concentration of residual uranium (C0*) in natural seawater after adsorbing uranium, while the rate of recovery of uranium (R) is decreased. With the increase of (G) the coefficient of distribution (Kd) decreases to a certain value and then a little rises again. 相似文献
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I. INTRODUCTION AHP resin is a new type of adsorbent and has been studied by the units concernedfor several years. There is little report about this work so far. AHP resin was synthesizedin aqueous phase with tetra-ethylene pentamine (TEPA), epichlorohydrin (ECH) andC-reagent as raw materials, and basic zinc carbonate (P_Z_n) and rubber solvent oil (120Gasoline) as pore-forming material. Compared with the technique of the amorphous lumpresin and that of the resin synthesized in oil phase, the new technique of resin synthesizedin aqueous phase manifests many advantages, such as raising the capacity of uranium-adsorption of the resin, simplifying the after-treatment process, reducing the cost, etc. Sea water, in which all kinds of cation and anion exist, is a system of electrolytes,and the concentrations of many ions are higher than the concentration of uranium for 相似文献
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日本的海水化学资源提取技术研究 总被引：3，自引：0，他引：3
海水化学资源例如铀、锂提取技术已进入海水现场小规模试验。以纤维状偕胺肟类化合物为吸附材料 ,每公斤吸附剂的提铀量为 1 g。添加质量分数为 2 0 %聚氯乙烯的尖晶石型锰氧化物粒状海水提锂吸附剂 ,每克吸附剂的提铀量为 1 8mg。浮体式吸铀装置可用于深海作业。流动床或船舶提锂系统 ,可规模化海水提锂。吸锂剂的脱附以及脱锂液的浓缩分离已初步达到小型生产的程度。用吸附法从海水中提取的碳酸锂纯度达 99%以上 ,海水锂回收率为 2 7%。 相似文献
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应用有机吸附剂从海水中提取铀,资料上已有若干报道.Davies.R.J,等曾经报道过用甲醛、间苯二酚胂酸缩合的树脂,虽然这种树脂交换容量大(通水112天,1010微克铀/克),选择性好,提取率高,但它在水中缓慢水解,吸附能力下降,溶损也较大(2.3%初量/周),因而没有得到进一步的发展.Bayer,E.提出用聚乙二醛三氨基苯酚和经硅藻土烧结的聚丙烯氧肟酸树脂,从海水中提取铀和铜等金属,但吸附量不很高,树脂的强度也差,因此很快就中断了研究.苏联一些学者也报道了用AH、等阴离子交换树脂提取铀的研究工作.AH-2Φ树脂具有一定的吸附量(30微克铀/克),在海水中比较稳定,但交换容量很低,价格也较贵. 相似文献
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-The i. r. spectra of Na4 [UO2 (CO3)3], Na [UO2 (OH)3] and the surface species of uranium on HTO underthe condition of flowing natural seawater and concentrated seawater (NaCl-NaHCO3-U) were recorded, with the bands of urany! of surface species obtained and the finding that iigands of surface species besides HTO are mainly water and OH, and there are some CO32- groups under the condition of natural seawater. Some relations between the complex properties and the j. r. spectroscopic characters for uranyl complexes were studied, and the transferred change quantity of surface complex was calculated.Structure models for surface species of adsorption are herein presented and the mechanism for uranium adsorption is deduced. 相似文献