离子色谱法对阴离子分析方法的探讨

通过选择放大倍数、确定样品稀释倍数、加标回收等不同条件,运用离子色谱法对降水、饮用水、地表水中的F-,CL-,NO-2,NO-3加4进行了大量的实验分析。方法具有良好的线性(相关系数在0.9991～0.9997)和重复性(相对标准偏差小于1.9%),NO-3,SO2-标平均回收率为98.6%。方法简便实用,用于实际样品分析,所得结果令人满意。     

Ozone decomposition under the irradiation of 253.7 nm in the presence of methyl bromide

ＩｎｔｒｏｄｕｃｔｉｏｎＯｖｅｒｐａｓｔｔｅｎ ｙｅａｒｓ,ｔｈｅｓｔｒａｔｏｓｐｈｅｒｉｃｏｚｏｎｅｄｅｐｌｅｔｉｏｎｈａｓｂｅｅｎｃｏｎｔｒｉｂｕｔｅｄｔｏｔｈｅａｃｔｉｖｅｃｈｌｏｒｉｄｅａｎｄｂｒｏｍｉｄｅ(Ｈａｒｒｉｓ,1995) .Ａｌｔｈｏｕｇｈｔｈｅｃｏｎｃｅｎｔｒａｔｉｏｎｏｆｂｒｏｍｉｄｅｉｓｍｕｃｈｌｅｓｓｔｈａｎｔｈａｔｏｆｃｈｌｏｒｉｄｅ,ｔｈｅｏｚｏｎｅｄｅｐｌｅｔｉｏｎｅｆｆｉｃｉｅｎｃｙｏｆｂｒｏｍｉｄｅｉｓ 50ｔｉｍｅｓｇｒｅａｔｅｒ (Ｈａｒｒｉｓ,1995;ＭｃＥｌｒｏｙ ,1986)…     

大孔阴树脂及其白球对水中低浓度苯酚吸附行为的研究

研究了作为高分子材料的大孔阴树脂及其对应白球对水中低浓度苯酚的吸附行为，详细考察了吸附过程的吸附容量、速度等吸附参数以及ｐＨ、Ｃａ＾２＋、腐殖质等因素对吸附的影响，并对试验结果从理论上进行了分析与探讨。     

CPAM二次改性有机膨润土的脱色性能研究

分别用十六烷基三甲基溴化铵(CTMAB)和阳离子聚丙烯酰胺(CPAM)改性钠基膨润土,并用CPAM二次改性CTMAB插层膨润土,分析了三种改性后的膨润土的结构并研究了对模拟印染废水的吸附脱色性能。结果表明,经过CPAM二次改性过的CTMAB插层膨润土的层间距d001大于CTMAB改性膨润土、CPAM改性膨润土和钠基膨润土,且二次改性膨润土的脱色效果最佳。用50mg二次改性膨润土处理200mL浓度为30mg/L的活性艳红模拟印染废水时脱色率就可达90%以上,且沉降速度快,表现出良好的吸附、脱色、絮凝沉降的协同效应。     

城市绿地对空气负离子的影响

在南昌市选择有典型特征的城市绿地,对其在不同环境状况下的空气正、负离子浓度进行监测。研究结果表明:(1)城市绿地能有效提高空气负离子数量;(2)乔、灌、草3种不同类型的绿地中,以乔木林对提高空气负离子浓度和改善空气质量的作用最为显著;(3)在城市环境下,不同林分结构类型的乔木片林对空气负离子水平以及空气质量指数(CI)的影响差异不显著;(4)天气条件对绿地的空气负离子水平存在显著影响;(5)喷泉对空气负离子有显著影响。喷泉周围空气负离子浓度节律性振荡周期与喷泉的喷水变化周期相吻合。喷泉对空气负离子浓度以及CI的影响随着距离的增加而迅速减小。     

CuBr2分解缓释-膜催化对零价汞的氧化性能研究

以置于多孔陶瓷膜中的CuBr2受热分解所释放的Br2为氧化剂,利用膜催化装置对Hg0氧化效率进行研究,并设计反应-就地检测一体化装置,避免下游气体管壁效应对实验结果带来的影响.结果表明,MnO x/α-Al2O3催化膜对CuBr2分解所产生Br2的释放有较好的"缓释"作用.Hg0和Br2在催化膜表面的吸附和反应可用Langmuir-Hinshelwood机制描述.Hg0氧化效率随Br2浓度增大而升高,但在达到一定浓度后,Hg0和Br2的吸附速率及两者在催化膜表面的反应速率成为限速因素.473~573 K时Hg0氧化效率变化较稳定.烟气中SO2对Hg0氧化有一定抑制作用,NO无明显影响.     

A comparative study and evaluation of sulfamethoxazole adsorption onto organo-montmorillonites

Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole（SMX） were investigated. The surfactants used were cetyltrimethyl ammonium bromide（CTMAB）, 3-（N,N-dimethylhexadecylammonio） propane sulfonate（HDAPS） and 1,3-bis（hexadecyldimethylammonio）-propane dibromide（BHDAP）. The properties of the organo-montmorillonites were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption isotherm measurements. Results showed that the interlayer spacing of montmorillonite was increased and the surface area as well as the morphology were changed. Batch adsorption experiments showed that the surfactant loading amount had a great effect on the adsorption of SMX. The adsorption process was p H dependent and the maximum adsorption capacity was obtained at p H 3 for HDAPS-Mt, while CTMAB-Mt and BHDAP-Mt showed a high removal efficiency at 3–11. The adsorption capacity increased with the initial SMX concentration and contact time but decreased with increasing solution ionic strength.Kinetic data were best described by the pseudo second-order model. Equilibrium data were best represented by the Langmuir model, and the Freundlich constant（n） indicated a favorable adsorption process. The maximum adsorption capacity of SMX was 235.29 mg/g for CTMAB-Mt, 155.28 mg/g for HDAPS-Mt and 242.72 mg/g for BHDAP-Mt. Thermodynamic parameters were calculated to evaluate the spontaneity and endothermic or exothermic nature. The adsorption mechanism was found to be dominated by electrostatic interaction,while hydrophobic interaction played a secondary role.     

Synthesis of mesoporous Cu/Mg/Fe layered double hydroxide and its adsorption performance for arsenate in aqueous solutions

The mesoporous Cu/Mg/Fe layered double hydroxide(Cu/Mg/Fe-LDH) with carbonate intercalation was synthesized and used for the removal of arsenate from aqueous solutions.The Cu/Mg/Fe-LDH was characterized by Fourier transform infrared spectrometry,X-ray diffraction crystallography,scanning electron microscopy,X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller.Effects of various physico-chemical parameters such as pH,adsorbent dosage,contact time and initial arsenate concentration on the adsorption of arsenate onto Cu/Mg/Fe-LDH were investigated.Results showed that it was efficient for the removal of arsenate,and the removal efficiency of arsenate increased with the increment of the adsorbent dosage,while the arsenate adsorption capacity decreased with increase of initial pH from 3 to 11.The adsorption isotherms can be well described by the Langmuir model with R 2 > 0.99.Its adsorption kinetics followed the pseudo second-order kinetic model.Coexisting ions such as HPO42-,CO32-,SO42and NO3could compete with arsenate for adsorption sites on the Cu/Mg/Fe-LDH.The adsorption of arsenate on the adsorbent can be mainly attributed to the ion exchange process.It was found that the synthesized Cu/Mg/Fe-LDH can reduce the arsenate concentration down to a final level of < 10 μg/L under the experimental conditions,and makes it a potential material for the decontamination of arsenate polluted water.     

Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies

The effects of dissolved organic matter (DOM) on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 (A300) and Purolite A 520E (A520E), would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Freundlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t 1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.     

离子色谱法中高浓度盐基体对无机阴离子分析影响规律的研究

本文首次研究高浓度盐基体中，大量盐的存在对无机阴离子的保留时间，峰高峰面积等参数的影响规律，并对其影响机理进行了初步探讨，实验证明，在样品中离子总浓度不超过柱容量孤情况下，虽然由于某些离子的浓度过高，使待测离子的保留时间变短，峰形改变，但用峰面积和标准加入外推法计算，仍可得到较即的结果。