首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到16条相似文献,搜索用时 78 毫秒
1.
铀在土壤中的吸附动力学   总被引:1,自引:0,他引:1  
胡立  梁斌  周敏娟 《四川环境》2011,30(1):21-25
以四川盆地红层丘陵区涪江河谷两岸广泛分布的第四系中更新统亚粘土为对象,用动态法测定了铀在该土壤中的平衡吸附量,为极低放废物的处置提供一些理论依据。研究了流速、土壤粒度及铀溶液初始浓度对土壤吸附铀的影响,并用常用的吸附动力学方程对实验数据进行了拟合。结果表明:土壤粒度小的平衡吸附量较大;流速越小、平衡吸附量越大;铀溶液的初始浓度越大,平衡吸附量越大;在用动力学方程拟合时,E lovich方程的拟合度最好;该土壤对铀的最大吸附率为61.1%,吸附性能较差。  相似文献   

2.
铀吸附实验研究现状   总被引:3,自引:0,他引:3  
李爽  倪师军  张成江 《四川环境》2007,26(1):77-79,84
介绍了铀吸附实验的研究现状,对吸附铀的各种载体进行了总结。目前,主要采用静态法(批示法)和动态法(柱法)进行铀的吸附实验研究。吸附铀的载体主要有粘土,金属的水合氧化物等肢体,藻类及菌类,树脂等。主要考察pH值、温度、吸附时间、阴离子、阳离子、细菌浓度、铀浓度等对吸附速率及吸附量的影响。  相似文献   

3.
生物吸附法处理水体中的重金属的现状与展望   总被引:5,自引:0,他引:5  
对生物吸附法处理水体中的重金属进行了综述,得出微生物对重金属表现出良好的吸附性能,吸附机理比较复杂,与离子交换有密切关系,常用吸附等温线评价微生物对重金属的吸附能力。由于该研究历史比较短,生物吸附的工艺应用、机理分析、生物固定化等研究还不够深入,有待进一步的研究探索,使其应用于工业生产。  相似文献   

4.
有机物生物吸附研究进展   总被引:6,自引:0,他引:6  
生物吸附是有效处理难降解有机物的技术之一。本文从生物吸附的概念、生物吸附过程、吸附剂的制备及再生、生物吸附影响因素等方面进行了综述,同时阐述了生物吸附有机物的技术研究进展和应用前景展望。  相似文献   

5.
生物吸附研究进展   总被引:24,自引:1,他引:24  
生物吸附法是目前处理含金属废水的一种较有效的方法,特别是对于低浓度废水的处理优势明显。生物吸附法处理废水亦可达到以废治废的目的。本文就生物吸附领域目前研究状况进行了概述,主要包括了生物吸附剂对金属离子的吸附作用,生物吸附机理以及固定化吸附的应用研究。  相似文献   

6.
生物吸附法处理水体中的重金属的现状与展望   总被引:1,自引:0,他引:1  
对生物吸附法处理水体中的重金属进行了分析,得出微生物对重金属表现出良好的吸附性能;吸附机理比较复杂,与离子交换有密切关系;常用吸附等温线评价微生物对重金属的吸附能力。由于研究的历史比较短,生物吸附的工艺应用、机理分析、生物粒化方面的研究还不够深入,有待进一步的研究,使其应用于工业生产。  相似文献   

7.
生物吸附法处理水体中的重金属的现状与展望   总被引:8,自引:0,他引:8  
对生物吸附法处理水体中的重金属进行了综述,得出微生物对重金属表现出良好的吸附性能。吸附机理比较复杂,与离子交换有密切关系,常用吸附等温线评价微生物对重金属的吸附能力。由于研究的历史比较短,生物吸附的工艺应用、机理分析、生物固定化方面的研究还不够深入,有待进一步的研究,使其应用于工业生产。  相似文献   

8.
重金属生物吸附研究进展   总被引:10,自引:0,他引:10  
本文综述了生物吸附剂的种类、生物吸附的机理和影响因素,并介绍了生物吸附的有关研究进展。  相似文献   

9.
挥发性有机废气净化技术研究进展   总被引:16,自引:4,他引:16  
樊奇  羌宁 《四川环境》2005,24(4):40-44,49
本文对生物净化技术、等离子体净化技术、吸附和催化氧化技术在控制废气中挥发性有机物的研究进展及应用进行了综述。气体生物净化技术在VOCs混合物和改进设备工艺方面开展的研究工作较多,等离子体净化技术与催化技术的组合越来越受到关注。吸附和催化氧化方面则着重在吸附剂(活性炭和沸石)吸附性能的进一步研究和新型催化剂的研制。  相似文献   

10.
改性木屑吸附剂对印染废水的脱色性能研究   总被引:1,自引:0,他引:1  
本文介绍了以廉价易得的杨树木屑为原料,经环氧氯丙烷交联,制备的一种新的生物吸附剂,研究各种反应因素(氢氧化钠浓度、环氧氯丙烷用量、反应温度、木屑粒径等)对反应过程和吸附剂性能的影响,检验了其对品红及孔雀石绿在不同条件下的吸附性能,并探讨了它的吸附动力学曲线和再生性能。  相似文献   

11.
The microalgae Chlamydomonas reinhardtii was used for the biosorption of Hg(II), Cd(II) and Pb(II) ions. The maximum adsorption of Hg(II) and Cd(II) ions on Chlamydomonas reinhardtii biomass was observed at pH 6.0 and the corresponding value for Pb(II) ions was 5.0. The biosorption of Hg(II), Cd(II) and Pb(II) ions by microalgae biomass increased as the initial concentration of Hg(II), Cd(II) and Pb(II) ions increased in the biosorption medium. The maximum biosorption capacities of microalgae for Hg(II), Cd(II) and Pb(II) ions were 72.2+/-0.67, 42.6+/-0.54 and 96.3+/-0.86 mg/g dry biomass, respectively. The affinity order for algal biomass was Pb(II)>Hg(II)>Cd(II). FT-IR analysis of algal biomass revealed the presence of amino, carboxyl, hydroxyl and carbonyl groups, which were responsible for biosorption of metal ions. Biosorption equilibrium was established in about 60 min and the equilibrium was well described by the Freundlich biosorption isotherms. Temperature change in the range of 5-35 degrees C did not affect the biosorption capacity. The microalgae could be regenerated using 0.1 M HCl, with up to 98% recovery, which allowed the reuse of the biomass in six biosorption-desorption cycles without any considerable loss of biosorption capacity.  相似文献   

12.
Dye wastewater is one of the most difficult to treat. There has been exhaustive research on biosorption of dye wastewater. It is evolving as an attractive option to supplement conventional treatment processes. This paper examines various biosorbents such as fungi, bacteria, algae, chitosan and peat, which are capable of decolorizing dye wastewaters; discusses various mechanism involved, the effects of various factors influencing dye wastewater decolorization and reviews pretreatment methods for increasing the biosorption capacity of the adsorbents. The paper examines the mismatch between strong scientific progress in the field of biosorption and lack of commercialization of research.  相似文献   

13.
利用黑曲霉常用液体培养基对黄孢原毛平革菌进行扩大培养,得到的菌丝球用于吸附废水中的Cd^2+和Zn^2+。本研究考察了初始pH、吸附时间以及共存离子对P.chrysosporium菌丝球吸附Cd^2+和Zn^2+的影响。在相同的实验条件下,研究重金属溶液初始浓度对吸附的影响发现其吸附曲线呈L2型,对重金属终浓度以及吸附量进行线性转换,发现Langmuir和Freundlich吸附模型能较好的描述P.chrysosporium菌丝球对Cd^2+和Zn^2+的吸附。将P.chrysosporium吸附Zn^2+和Cd^2+前后的红外光谱图作比较,发现P.chrysosporium吸附Zn^2+和Cd^2+后的主要成分和结构保持完整,3302cm^-1叫峰位分别移动61cm^-1和94cm^-1。  相似文献   

14.
Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures.As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g?1 for copper(II) and from 23.74 to 26.27 for lead(II).Activation energy was higher for lead(II) (22.40 kJ mol?1) than for copper(II) (20.36 kJ mol?1). The free energy of activation was higher for lead(II) than for copper(II) and the values of ΔH* and ΔS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption.Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin–Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism.  相似文献   

15.
The cupuassu shell (Theobroma grandiflorum) which is a food residue was used in its natural form as biosorbent for the removal of C.I. Reactive Red 194 and C.I. Direct Blue 53 dyes from aqueous solutions. This biosorbent was characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption curves. The effects of pH, biosorbent dosage and shaking time on biosorption capacities were studied. In acidic pH region (pH 2.0) the biosorption of the dyes were favorable. The contact time required to obtain the equilibrium was 8 and 18 h at 298 K, for Reactive Red 194 and Direct Blue 53, respectively. The Avrami fractionary-order kinetic model provided the best fit to experimental data compared with pseudo-first-order, pseudo-second-order and chemisorption kinetic adsorption models. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Radke-Prausnitz isotherm models. For both dyes the equilibrium data were best fitted to the Sips isotherm model.  相似文献   

16.
Phenol and substituted phenols are toxic organic pollutants present in tannery waste streams. Environmental legislation defines the maximum discharge limit to be 5–50 ppm of total phenols in sewers. Thus the efforts to develop new efficient methods to remove phenolic compounds from wastewater are of primary concern. The present work aims at the use of a modified green macro alga (Caulerpa scalpelliformis) as a biosorbent for the removal of phenolic compounds from the post-tanning sectional stream. The effects of initial phenol concentration, contact time, temperature and initial pH of the solution on the biosorption potential of macro algal biomass have been investigated. Biosorption of phenol by modified green macro algae is best described by the Langmuir adsorption isotherm model. Biosorption kinetics of phenol onto modified green macro algal biomass were best described by a pseudo second order model. The maximum uptake capacity was found to be 20 mg of phenol per gram of green macro algae. A Boyd plot confirmed the external mass transfer as the slowest step involved in the biosorption process. The average effective diffusion coefficient was found to be 1.44 × 10−9 cm2/s. Thermodynamic studies confirmed the biosorption process to be exothermic.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号