吸附分离氯化钙中镁铅离子的试验研究

以去除纯碱副产物氯化钙中的镁铅离子,制取高纯氯化钙为目的,采用吸附的方法,研究了不同吸附剂对镁铅离子的分离效果,以及吸附时间、温度、pH值等因素对改性斜发沸石吸附效果的影响。试验结果表明:改性斜发沸石对氯化钙中镁铅离子有较好的吸附去除效果,吸附时间100min、温度30℃、100ml质量分数为0.5%的氯化钙溶液加吸附剂1.5g、pH10为最优吸附条件。     

改型沸石对氢氧根离子的吸附和再生研究

天然斜发沸石在碱性介质中会吸附OH~-,致使对其他离子的吸附及离子交换能力下降,甚至失去吸附及离子交换能力。研究结果表明,在相同OH~-浓度的碱溶液中,钙型和镁型天然斜发沸石对Ca(OH)_2溶液中的OH~-单位吸附量最大,钙型沸石的饱和吸附量为22.21 mg/g,镁型沸石的饱和吸附量为25.30 mg/g。而且氢氧根离子浓度越高,钙型沸石和镁型沸石的平衡吸附量就越大,随着温度的升高这个趋势更加明显。通过对吸附OH~-后的天然斜发沸石的解吸、再生和改型,所得钠型斜发沸石对海水中K~+的饱和吸附量为18 mg/g左右,仍然符合海水提钾对斜发沸石的质量要求。     

改性沸石去除废水中Zn^2＋的试验

采用NaCl-MnO2联合的方式对天然斜发沸石进行改性,在静态条件下,对改性斜发沸石处理模拟含锌废水进行了试验研究,考察了吸附时间、吸附剂投量、Zn^2＋初始浓度和pH对改性斜发沸石吸附Zn^2＋的影响。结果表明：当温度为25℃、pH为5.0～6.0、Zn^2＋初始浓度≤50 m g/L时,按锌与改性斜发沸石质量比为1：40投加改性斜发沸石进行处理,Zn^2＋去除率可达90%以上,模拟含锌废水经改性沸石处理后,水中锌含量低于国家排放标准。改性斜发沸石对Zn^2＋的吸附规律符合Langm uir吸附等温线和准二级动力学模型,相关系数分别为0.927 5和0.999 2。     

氯化钠联合加热改性沸石处理亚甲基蓝废水的实验研究

氯化钠联合加热对沸石进行改性是一种操作简单、效果比较好的改性方法,主要是改变沸石的内部结构与表面结构来提高其吸附率。本文采用单因素实验法,对天然斜发沸石进行改性,实验结果表明,在氯化钠质量分数为12%、浸泡时间为90min、焙烧时间为120min、焙烧温度为90℃的条件下,改性的沸石对废水中亚甲基蓝吸附率最大。采用正交实验法研究改性沸石对废水中亚甲基蓝的吸附条件,当改性沸石投加量为0.15 g/m L、p H值为7、吸附温度为60℃、吸附时间为40min时,为最佳吸附条件,去除率达95.07%。     

改性沸石对废水中Cu2+、Cr3+的去除作用研究

用Na OH碱熔-水热法处理得到的改性斜发沸石作为吸附交换剂,对模拟废水中以Cu2+、Cr3+为代表的重金属离子进行吸附处理。研究了不同吸附时间、投加量以及初始浓度条件下,改性斜发沸石对Cu2+、Cr3+的去除效果。实验结果表明:改性沸石与水样中Cu2+、Cr3+的质量比分别为18.75∶1、13.33∶1时,对Cu2+、Cr3+的去除率分别达88.0%、87.4%,且为快速吸附平衡过程。此外,用Na Cl溶液和Na Cl溶液加氨水对吸附Cu2+饱和的改性沸石进行再生实验,再生率较高,改性斜发沸石可以多次重复利用。     

天然和改性沸石对铬吸附特征研究

通过不同方法对天然斜发沸石进行改性,研究改性沸石在不同温度和时间条件下对铬的吸附特征。结果表明:硫酸+硫酸铜复合改性吸附效果最好;铬浓度≤25 mg/L时,改性沸石吸附后的铬平衡浓度在1.5 mg/L以下,比天然沸石吸附后铬浓度下降更明显;当铬浓度为25 mg/L时,改性后沸石吸附率从79.844%增加到94.312%。吸附过程用Freundlich方程能较好拟合。1/n1,说明改性沸石对Cr6+吸附较难发生,但改性后吸附强度是天然沸石的8倍;改性沸石可较好用二级动力学模型模拟,理论吸附量Q=0.2367 mg/g,接近实测值0.2319 mg/g。Elovich方程拟合表明,在吸附过程中离子交换起到了较大作用,颗粒内扩散对于吸附过程有影响。     

改性上林沸石吸附选矿废水的研究

分别采用盐酸和氢氧化钠浸渍方法对上林沸石改性,改性沸石在溶液中搅拌情况下,吸附选矿废水中金属离子。考察溶液pH值、沸石粒度、吸附时间对Cu~(2+)和Zn~(2+)离子吸附性能的影响,溶液中金属离子浓度通过原子吸收光谱分析,结果表明,选矿废水中锌、铜离子去除率达99.8%。     

改性沸石去除废水中Zn2+的试验研究

采用Nacl-MnO2联合的方式对天然斜发沸石进行改性,在静态条件下,对改性沸石处理模拟含锌废水进行了试验研究,考察了吸附时间,吸附剂投量、Zn2+初始浓度和pH对改性沸石吸附Zn2+的影响.结果表明,在温度为25℃,pH为5.0～6.0,Zn2+初始质量浓度≤50 mg·L-1,按锌与改性沸石质量比为1.40投加改性沸石进行处理,Zn2+去除率可迭90%以上,模拟含锌废水经改性沸石处理后,水中锌含量低于国家排放标准.采用Langmuir吸附等温线和准二级动力学模型拟合改性沸石对Zn2+的吸附,结果表明,改性沸石对Zn2+的吸附能较好地符合Langmuir吸附等温线和准二级动力学模型,相关系数分别为0.927 5和0.9992.     

改性红辉沸石对水中Fe^3＋的吸附性能研究

为了提高红辉沸石在含金属废水治理方面的应用效果,通过大量实验确定,采用氯化铝和氯化镁共同对红辉沸石进行改性处理,可以大大提高红辉沸石对水溶液中金属离子的吸附效果。在不同改性条件下,研究了改性红辉沸石去除水溶液中Fe3＋的效果。实验结果表明：改性红辉沸石对Fe3＋有较好的吸附效果,改性剂用量、活化温度和活化时间是影响吸附的主要因素;当红辉沸石与改性剂用量比例为95：5（质量比）、活化温度为300℃、活化时间为1h时,改性红辉沸石对水溶液中Fe3＋的去除效果最佳。     

改性斜发沸石对含盐污水中氨氮和总磷吸附性能的研究

研究了NaCl改性斜发沸石对含盐污水中NH3-N和TP的吸附特性,进行了等温吸附实验、不同盐度条件下的吸附实验和动态吸附实验。等温吸附实验结果显示,盐度为1.5%、温度为25℃条件下,改性沸石对NH3-N和TP的饱和吸附量分别为0.912 mg/g和0.504 mg/g,较未改性沸石分别高出81%和66%。盐度升高会降低2种沸石对NH3-N和TP的吸附量,但在各种盐度条件下,改性沸石对NH3-N和TP的去除率均高于未改性沸石,最高可分别高出8个和6个百分点左右。动态吸附实验中,NH3-N在第102天达到吸附饱和,动态饱和吸附量为0.587 mg/g;TP在第16天达到吸附饱和,动态饱和吸附量为7.551μg/g。     

改性笋壳处理含铬废水的工艺研究

生物吸附法是一项处理重金属离子废水污染的新技术,在处理重金属污染废水和重金属回收方面有着广阔的应用前景,具有较好的经济价值和社会效益。本文主要研究改性笋壳为吸附剂去除废水中的铬离子,探讨振荡时间、吸附剂量、初始浓度、温度、pH对铬离子去除率的影响。结果表明:pH对铬离子去除率有很大影响,pH越低,吸附效果越好。当笋壳用量为0.5 g,、振荡时间为90 min,铬离子吸附率可达40%以上。     

Removal of heavy metals from aqueous solution by poly(acrylamide-co-acrylic acid) modified with porous materials

In this study, a series of poly acrylamide-co-acrylic acid/NaY zeolite, poly acrylamide-co-acrylic acid/MCM-41, and poly acrylamide-co-acrylic acid/clinoptilolite nanocomposites were synthesized. These materials were characterized by using FT-IR spectroscopy, XRD, TGA, and SEM. Removal capacity of Pb(II) and Cd(II) ions in aqueous solutions by using these nanocomposites was investigated with controlled time, initial metal ions concentration, pH values, adsorbent content, and temperature by using atomic absorption spectrometry. Results show that these nanocomposites have further adsorption related to NaY, MCM-41, and clinoptilolite. Poly(AAm-co-AAc)/NaY, poly(AAm-co-AAc)/MCM-41, and poly(AAm-co-AAc)/clinoptilolite exhibit superior Pb(II) (about 90–99%) and Cd(II) (about 88–98%) adsorption behavior at room temperature and the poly(AAm-co-AAc)/NaY nanocomposite had the best adsorption behavior. Finally, the equilibrium removal performance of the composites is analyzed according to the Langmuir and Freundlich adsorption isotherm model that shows result fitted to Langmuir model and have monolayer adsorption.     

Adsorption of cadmium on acid-modified Transcarpathian clinoptilolite

The adsorption properties of acid-modified Ukrainian Transcarpathian clinoptilolite towards aqueous cadmium(II) solutions under dynamic conditions have been investigated. It has been demonstrated that the adsorption capacity of the H-form of clinoptilolite depends on the nature and concentration of acid as well as the duration of contact of clinoptilolite with acid in the process of modification. The most effective adsorption of cadmium(II) was demonstrated by clinoptilolite pre-treated with 1 M of HCl during 24 h. It has been determined that the optimum for concentration of cadmium(II) is the H-form of clinoptilolite obtained without considerable dealumination. Under optimum conditions (diameter of zeolite grains equal to ca. 0.20–0.30 mm; flow rate of cadmium(II) solution of 500 ng/ml concentration through adsorbent equal to 3 ml/min; pH=5.6) the dynamic absorption capacity is 7.41 mg of cadmium per 1 g of acid-modified clinoptilolite. The conditions of desorption of cadmium from acid-modified clinoptilolite have been investigated. The solutions of potassium salts are the best desorbent of the ones that have been approved. The extraction of cadmium in these solutions reaches 88–92%.     

Kinetic,thermodynamic and equilibrium studies on the removal of copper ions from aqueous solutions by natural and modified clinoptilolites

This paper presents the adsorption of Cu(II) ions from aqueous solution on Na and Fe-modified clinoptilolite. The copper adsorption experiments were performed in a batch system considering an optimum contact time of 24 h. Changes in the surfaces and structure were characterized by SEM data. According to the SEM results, it was anticipated that the removal efficiency of Fe-modified clinoptilolite was the highest compared with the natural and Na-modified clinoptilolites. Adsorption of Cu(II) ions by modified clinoptilolites was investigated as a function of the initial Cu(II) concentration, solution pH, and temperature. According to the results, the maximum adsorbed Cu amount onto Fe-modified was 19.40mg/l at the optimum operating condition with a pH value of 5.5 and temperature of 60 °C. According to the thermodynamic evaluations, positive ΔS and negative ΔG were found for the adsorption process showing that the adsorption reaction is a spontaneous process and more favorable at high temperatures. Sorption data have been interpreted in terms of Langmuir and Freundlich, Temkin and Dubinin-Radushkevich. The adsorption equilibrium was best described by the Langmuir adsorption isotherm. In addition, according to the Sips model, the sorption of Cu(II) ions on the Fe-modified clinoptilolite was found to be heterogeneous. The kinetic study showed that the Fe-modified clinoptilolite followed the pseudo-second order model. The results indicated that the clinoptilolite-rich tuff in its iron oxide form could be efficiently used for the removal of copper from aqueous solutions.     

生物吸附剂及其在重金属废水处理中的应用进展

重金属离子严重危害人体健康,因此在废水处理中必须将其去除。传统去除重金属离子的方法很多,但都存在某些不足,近年发展起来的生物吸附技术,在水处理领域具有很好的应用前景。综述了近年来生物吸附剂在重金属废水处理中的应用情况,同时探讨了今后生物吸附法去除重金属的发展趋势。     

Efficient technology for the removal of iron and manganese ions from artesian water using clinoptilolite

A method and technology for the deposition of strongly bonded high-disperse manganese dioxide onto the external surface of clinoptilolite grains is developed. The optimal conditions for the application of thus prepared material for the purification of artesian water are determined. A two-stage process of water purification is proposed, which involves usual clinoptilolite filter at the first stage to remove the main amount of iron, and the filter with modified clinoptilolite on the second stage to remove the residual iron and bivalent manganese ions. The proposed technology of preparation and application of modified clinoptilolite is tested in industrial conditions.     

Fenton氧化-沸石吸附联合处理化学镀镍废水

以Ni~(2+)、总磷和氨氮为考察对象,采用Fenton氧化和沸石吸附联合处理化学镀镍废水。探讨了Fenton破络及协同氧化非正磷酸盐时,H_2O_2的质量浓度、m(Fe~(2+))∶m(H_2O_2)、初始pH值对Ni~(2+)和总磷去除率的影响。另外,研究了沸石吸附氨氮时,沸石量、吸附时间、吸附pH值对氨氮去除率的影响。结果表明:当H_2O_2的质量浓度为6.66g/L、m(Fe~(2+))∶m(H_2O_2)为0.06、初始pH值为3时,破络完全,非正磷酸盐转化率为99.45%;同时,Ni~(2+)和总磷的去除率分别达到99.72%和91.88%。当沸石量为8g/100mL、pH值为7、反应时间为60min时,氨氮的去除率为86.30%。     

Investigation of coagulation and electrokinetic behaviors of clinoptilolite suspension with multivalent cations

This paper presents the results of investigations concerning the influence of magnesium, copper, aluminum and ferric cations on the coagulation and electrokinetic behaviors of clinoptilolite suspension. While clinoptilolite exhibited a negative surface charge over a broad pH range and had no isoelectric point (iep), especially the trivalent ions strongly changed the sign and magnitude of the zeta potential of the mineral depending on pH and cation concentration. The coagulation of clinoptilolite particles with these metal cations also showed sharp dependences on pH and cation concentration. That is, the coagulation process significantly took place in the pH and concentration ranges in which metal hydroxides existed in the suspension. Moreover, the coagulation behavior of clinoptilolite at pH values below the iep of metal hydroxides was usually consistent with its zeta potential variation, indicating a coagulation process by the charge neutralization mechanism. However, at pH values larger than the iep of these hydroxides, sweep coagulation of clinoptilolite suspension occurred and a clear correlation between surface charge and the onset of coagulation was not determined.     

吸附法去除溶液中Mg~(2+)、Pb~(2+)的试验研究

以去除纯碱副产物氯化钙中的Mg2+和Pb2+,制取高纯氯化钙为目的,采用吸附的方法,研究了不同吸附剂对Mg2+、Pb2+的分离效果,以及吸附时间、温度、pH值等因素对改性斜发沸石吸附效果的影响。试验结果表明:改性斜发沸石对氯化钙中Mg2+、Pb2+有较好的吸附去除效果,吸附时间100min、温度30℃、100ml质量分数为0.5%的氯化钙溶液加吸附剂1.5g、pH10为最优吸附条件。