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1.
针铁矿对重金属Pb^2+、Cd^2+的吸附特征   总被引:1,自引:0,他引:1  
肖萍  袁林  魏世强 《四川环境》2009,28(1):17-19
本文采用平衡振荡法,主要探讨了重金属铅和镉在针铁矿上的环境行为。研究结果表明针铁矿对重金属有较强的吸附作用。在pH一定时,针铁矿对Pb^2+和Cd^2+的吸附率随着初始浓度的增加而增大。随着介质pH升高,针铁矿对Pb^2+和Cd^2+的吸附量与吸附率均增大,最大吸附率可达到99.71%和99.46%,而解吸量则随之降低。在高pH条件下,针铁矿对Pb^2+和Cd^2+的结合牢固,且与Pb^2+的稳定度大于Cd^2+。研究表明,环境中针铁矿对铅、镉等重金属的环境化学行为具有重要的影响。利用针铁矿处理含Pb^2+和Cd^2+的污水具有良好的应用潜力。  相似文献   

2.
去除淡水浮游藻类方法的研究进展   总被引:6,自引:0,他引:6  
边归国 《四川环境》2004,23(6):66-70
在春至秋季,由于环境污染的影响,我国许多湖泊和水库中经常发生水华现象。由于浮游藻类的存在以及在生长繁殖和死亡过程中所释放出的各种藻类毒素,对水生生物和人畜安全造成严重的影响。因此,必须采取科学的方法对浮游藻类予以去除。去除浮游藻类主要有物理除藻、化学除藻、生物除藻等方法。  相似文献   

3.
漆文光  陆少鸣 《四川环境》2006,25(3):18-21,49
本文通过分析饮用水深度处理中试工艺各处理单元出水水质指标的变化研究臭氧在臭氧生物活性炭工艺中的作用。试验结果表明:在中试工艺中,臭氧具有很好的氧化、杀藻和消毒的作用;并且两级臭氧氧化分别对常规处理单元和颗粒活性炭去除污染物具有一定的促进作用。  相似文献   

4.
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   

5.
不同环境中存在的抗生素会对人类的健康产生威胁。吸附法作为一种高效、简单的抗生素去除技术是目前的研究热点。然而,不同环境中普遍存在的溶解性有机物(Dissolved Organic Matter, DOM)会对抗生素的吸附过程产生影响。对人工合成材料体系(石墨烯和生物炭)和自然体系(土壤和底泥)中DOM对抗生素吸附过程的影响进行了梳理,同时总结了DOM影响抗生素吸附的机理,并对今后的研究趋势进行展望,以期能为环境中抗生素的吸附去除提供一定的参考。  相似文献   

6.
以牛粪生物炭为吸附剂,通过静态吸附实验研究牛粪生物炭对磷的吸附特性。研究了pH值、投加量等对牛粪生物炭吸附磷的影响。结果表明,牛粪生物炭吸附磷的最佳初始pH值为6.0;当投加量为0.1 g时,对磷的去除较为理想;通过对动力学数据进行分析,发现准二级动力学(R~2=0.999)比准一级动力学方程(R~2=0.5 886)和Elovich方程(R~2=0.927)能更好的拟合动力学数据,颗粒内扩散方程拟合结果发现牛粪生物炭对磷的吸附包括表面吸附和颗粒内扩散两个过程。吸附等温线拟合发现Langmuir吸附等温方程能很好拟合等温吸附数据,表明生物炭对磷的吸附以单分子层吸附模式为主。  相似文献   

7.
干旱区牛粪生物炭对水中磷的吸附特性研究   总被引:2,自引:0,他引:2  
以牛粪生物炭为吸附剂,通过静态吸附实验研究生物炭对磷的吸附特性。通过对动力学数据进行分析,发现准二级动力学(R2=0.999)比准一级动力学方程(R2=0.5886)和Elovich方程(R2=0.927)能更好地拟合动力学数据,颗粒内扩散方程拟合结果发现牛粪生物炭对磷的吸附包括表面吸附和颗粒内扩散两个过程。吸附等温线拟合发现Langmuir吸附等温方程能很好拟合等温吸附数据,表明生物炭对磷的吸附以单分子层吸附模式为主。利用牛粪热解产生的生物炭吸附去除水中磷是可行的,不仅成本低廉并且能够达到干旱区农业废弃物资源化利用及废水除磷的目的。  相似文献   

8.
生物吸附剂及其吸附性能研究进展   总被引:11,自引:0,他引:11  
昝逢宇  赵秀兰 《青海环境》2004,14(1):15-18,40
用微生物体来吸附水中的重金属是一项新兴的废水生物处理技术。藻类、细菌、真菌等是生物吸附剂的来源 ,它们对多种重金属都有较好的吸附去除效果。文章从细胞壁的结构特性概述了藻类、细菌、真菌等对重金属吸附的机理 ,介绍了它们的吸附性能  相似文献   

9.
以地表水为水源的自来水厂,原水藻类的去处是个极其复杂的课题。某水厂通过对不同除藻防藻技术的实际应用及效果比较,最终形成了生物(鲢鱼)控藻+活性炭吸附+强化常规工艺除藻的联合除藻措施,收到了较好的除藻效果。  相似文献   

10.
以钛酸四丁酯为原料,利用水解法构造了Ti-O-Ti的空间结构,通过添加有机硝酸铁和磷酸氢二铵两种原料,向其空腔内引入Fe、P双元素掺杂,得到P-FeN-TiO2复合材料。使用扫描电镜(SEM)观察了材料的表面形貌,通过吸附等温线、吸附动力学拟合模型分析材料对铊的吸附性能;考察不同溶液pH值、阳离子共存时对铊吸附进程的影响。结果表明:P-Fe-TiO2复合材料具有多孔结构,吸附符合单分子层吸附,Langmuir拟合最大吸附容量283.1 mg/g,吸附大约2 h达到平衡,强酸性环境会抑制铊的吸附,随着p H值的升高吸附容量逐渐增大,K(Ⅰ),Na(Ⅰ)离子的存在对吸附干扰较小,Ca(Ⅱ)离子的存在会与Tl(Ⅰ)竞争有效的吸附结合位点,导致吸附效率降低,根据吸附前后材料的XPS表征分析,P-FeN-TiO2复合材料对Tl(Ⅰ)的吸附机理为Ti-OH、P=O、Fe-OH三种基团与Tl(Ⅰ)发生了络合作用,从而实现铊的去除。  相似文献   

11.
采用室内溶液培养法研究了Pb^2+、Cr^6+、Cd^2+单一及其复合污染对白蝴蝶叶片过氧化氢酶(CAT)和过氧化物酶(POD)活性的影响。结果表明在处理浓度范围内,处理后白蝴蝶叶片CAT活性明显高于对照,随着各处理浓度的增加,表现先升高后降低最后再上升的趋势。经Cd^2+及复合污染处理后,白蝴蝶叶片内POD活性变化趋势与CAT活性相似;但是经Pb^2+、Cr^6+处理后,其POD活性变化趋势与CAT不同,即在高浓度处理下,POD活性明显低于对照。当处理浓度为100mg/L时,POD活性随着处理时间的延长表现出先升高再降低的趋势。可以认为,酶活性升高是由于白蝴蝶对Pb^2+、Cr^6+、Cd^2+单一及其复合胁迫做出的应激反应。  相似文献   

12.
The present study investigated the effectiveness of an inexpensive and ecofriendly alumino silicate clay mineral, sericitic pyrophyllite, as an adsorbent for the possible application in the removal of some divalent toxic metal cations such as Pb(2+), Cu(2+)and Zn(2+) from aqueous systems. Batch scale equilibrium adsorption studies were carried out for a wide range of initial concentration from 24.1 to 2410mumolL(-1) for lead, 78.65 to 7865mumolL(-1) for copper and 76.45 to 7645mumolL(-1) for zinc solutions. The removal of Pb(2+) was almost complete at low concentration (maximum lead removal capacity, LRC, 32mg of lead/g of pyrophyllite) with 10gL(-1) of adsorbent in a 30min equilibration time. The effects of temperature on adsorption of heavy metal ions were studied. The applicability of the Langmuir, Freundlich and Dubinin-Radushkevich adsorption models in each case of lead, copper and zinc adsorption was examined separately at different temperatures. The adsorption process was found to be endothermic and the Freundlich adsorption model was found to represent the data at different temperatures more suitably.  相似文献   

13.
本实验目的是研究草木灰对吸附亚甲基蓝的去除效果,探讨了亚甲基蓝初始量、吸附时间、pH值等对吸附效果的影响,并运用伪一级、伪二级反应动力学模型和Laugmuir、Freundlich等温线模型进行拟合。结果表明,草木灰对亚甲基蓝溶液的吸附在5 min~30 min速率比较快,约在65 min内达到吸附平衡,pH越大越有利于吸附,浓度在5mg/L时草木灰对亚甲基蓝的吸附最佳。与伪二级动力学曲线模型拟合效果较好,由Laugmuir等温线模型计算得出理论最大吸附容量Qm为2.275 mg/g,吸附性能优异。  相似文献   

14.
不溶性淀粉黄原酸酯处理含镉废水的研究   总被引:3,自引:0,他引:3  
刘志昌  刘凡  唐琼  张一 《四川环境》2006,25(5):12-14
本文以环氧氯丙烷与淀粉进行交联反应,然后再进行黄原酸化反应制得不溶性淀粉黄原酸酯(ISX),用ISX对含镉废水进行了处理试验,对其去除效果及影响因素进行了实验研究,并对其去除机理进行了初步探讨。试验结果表明,当其用量为651mg/L时,Cd^2+离子去除率达99.30%。与其它方法相比,该法具有成本低、操作简单、无毒无害、易于分离、去除率高,回收废渣处理不会引起二次污染等优点。  相似文献   

15.
Adsorption characteristics of Cu and Ni on Irish peat moss   总被引:1,自引:0,他引:1  
Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu(2+) and Ni(2+) from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5-100mg/L. The pH of the solutions containing either Cu(2+) or Ni(2+) was varied over a range of 2-8. The adsorption of Cu(2+) and Ni(+2) on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6 mg/g for Cu(2+) and 14.5mg/g for Ni(2+) at 298 K when the initial concentration for both Cu(2+) and Ni(2+) was 100mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.  相似文献   

16.
Adsorption-desorption characteristics of mercury in paddy soils of China   总被引:1,自引:0,他引:1  
Mercury (Hg) has received considerable attention because of its association with various human health problems. Adsorption-desorption behavior of Hg at contaminated levels in two paddy soils was investigated. The two representative soils for rice production in China, locally referred to as a yellowish red soil (YRS) and silty loam soil (SLS) and classified as Gleyi-Stagnic Anthrosols in FAO/UNESCO nomenclature, were respectively collected from Jiaxin County and Xiasha District of Hangzhou City, Zhejiang Province. The YRS adsorbed more Hg(2+) than the SLS. The characteristics of Hg adsorption could be described by the simple Langmuir adsorption equation (r2 = 0.999 and 0.999, P < 0.01, respectively, for the SLS and YRS). The maximum adsorption values (Xm) that were obtained from the simple Langmuir model were 111 and 213 mg Hg(2+) kg(-1) soil, respectively, for the SLS and YRS. Adsorption of Hg(2+) decreased soil pH by 0.75 unit for the SLS soil and 0.91 unit for the YRS soil at the highest loading. The distribution coefficient (kd) of Hg in the soil decreased exponentially with increasing Hg(2+) loading. After five successive desorptions with 0.01 mol L(-1) KCl solution (pH 5.4), 0 to 24.4% of the total adsorbed Hg(2+) in the SLS soil was desorbed and the corresponding value of the YRS soil was 0 to 14.4%, indicating that the SLS soil had a lower affinity for Hg(2+) than the YRS soil at the same Hg(2+) loading. Different mechanisms are likely involved in Hg(2+) adsorption-desorption at different levels of Hg(2+) loading and between the two soils.  相似文献   

17.
天然硅藻土作为吸附材料处理渗滤液的效果研究   总被引:2,自引:0,他引:2  
利用天然硅藻土在静态条件下对垃圾渗滤液中的氨氮和COD的吸附效果进行了研究。结果表明:天然硅藻土对于氨氮的去除效率只有14.1%;但对COD的去除效率可以达到70.1%;天然硅藻土对于COD的饱和吸附量和吸附速度明显高于其对氨氮的饱和吸附量及吸附速度;在平衡浓度相当高的情况下,每克硅藻土具有吸附65.31mg COD的极限潜力。  相似文献   

18.
Resting (living) bio-sludge from a domestic wastewater treatment plant was used as an adsorbent of both direct dyes and organic matter in a sequencing batch reactor (SBR) system. The dye adsorption capacity of the bio-sludge was not increased by acclimatization with direct dyes. The adsorption of Direct Red 23 and Direct Blue 201 onto the bio-sludge was almost the same. The resting bio-sludge showed higher adsorption capacity than the autoclaved bio-sludge. The resting bio-sludge that was acclimatized with synthetic textile wastewater (STWW) without direct dyes showed the highest Direct Blue 201, COD, and BOD(5) removal capacities of 16.1+/-0.4, 453+/-7, and 293+/-9 mg/g of bio-sludge, respectively. After reuse, the dye adsorption ability of deteriorated bio-sludge was recovered by washing with 0.1% sodium dodecyl sulfate (SDS) solution. The direct dyes in the STWW were also easily removed by a GAC-SBR system. The dye removal efficiencies were higher than 80%, even when the system was operated under a high organic loading of 0.36kgBOD(5)/m(3)-d. The GAC-SBR system, however, showed a low direct dye removal efficiency of only 57+/-2.1% with raw textile wastewater (TWW) even though the system was operated with an organic loading of only 0.083kgBOD(5)/m(3)-d. The dyes, COD, BOD(5), and total kjeldalh nitrogen removal efficiencies increased up to 76.0+/-2.8%, 86.2+/-0.5%, 84.2+/-0.7%, and 68.2+/-2.1%, respectively, when 0.89 g/L glucose (organic loading of 0.17kgBOD(5)/m(3)-d) was supplemented into the TWW.  相似文献   

19.
Phosphorus removal in vegetated filter strips   总被引:5,自引:0,他引:5  
Vegetated filter strips (VFS) are used recently for removal, at or near the source, of sediment and sediment-bound chemicals from cropland runoff. Vegetation within the flowpath increases water infiltration and decreases water turbulence, thus enhancing pollutant removal by sedimentation within filter media and infiltration through the filter surface. Field experiments have been conducted to examine the efficiency of vegetated filter strips for phosphorus removal from cropland runoff with 20 filters with varying length (2 to 15 m), slope (2.3 and 5%), and vegetated cover, including bare-soil plots as control. Artificial runoff used in this study had an average phosphorus concentration of 2.37 mg L(-1) and a sediment concentration of 2700 mg L(-1). The average phosphorus trapping efficiency of all vegetated filters was 61% and ranged from 31% in a 2-m filter to 89% in a 15-m filter. Filter length has been found to be the predominant factor affecting P trapping in VFS. The rate of inflow, type of vegetation, and density of vegetation coverage had secondary influences on P removal. Short filters (2 and 5 m), which are somewhat effective in sediment removal, are much less effective in P removal. Increasing the filter length beyond 15 m is ineffective in enhancing sediment removal but is expected to further enhance P removal. Sediment deposition, infiltration, and plant adsorption are the primary mechanisms for phosphorus trapping in VFS.  相似文献   

20.
Carbonaceous adsorbents (CAs) are developed from used tire rubber (UTR) and tested as adsorbents of Cd(2+) in aqueous solution. In the preparation of the CAs, UTR was treated thermally at 400-900 °C for 2 h in N(2) and at 850 °C for 2 h in steam. Concentrated NaOH, HCl, H(2)SO(4), HNO(3) and H(2)O(2) solutions were also used. UTR and H900 (i.e. UTR pyrolyzed at 900 °C) were treated with O(3) at 25 °C for 1 h and with air at 250 °C for 1 and 24 h. CAs were characterized texturally by N(2) adsorption at -196 °C, mercury porosimetry, and density measurements. The surface groups were analyzed by FT-IR spectroscopy. Using the batch method, the adsorption process of Cd(2+) was studied mainly from the kinetic standpoint at various pH values of the adsorptive solution. Significant porosity developments are achieved only when UTR is heat-treated, in particular in steam. However, the variety and concentration of surface groups are low in CAs. This is so even for CAs prepared using oxidizing agents as strong as O(3) and H(2)O(2), which has been associated with a lack of available or accessible surface active sites for oxidation in UTR and H900, respectively. Thermal and thermal-chemical treatments are usually more effective than chemical treatments to increase the adsorption of Cd(2+) in aqueous solution. The adsorption process of Cd(2+) is first fast and then much slower. Adsorption-time data fit better to a pseudo-second order kinetic equation than to a pseudo-first order kinetic equation. The extent to which the adsorption process occurs is strongly dependent on the pH of the Cd(2+) solution, being larger at pH 4.6 or 7.0 according to the adsorbent.  相似文献   

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