Characteristics of NO reduction with non-thermal plasma

As a new type of NO removal system, NO reduction in N2-NO plasma was applied to solve the difficulties in the traditional methods, such as higher energy-consumption, larger equipment size and high cost, and so on. Using the experimental NO reduction system with single-pair electrode tip discharge structure, the NO reduction characteristics of N~-NO system were revealed to guide the engineering practice; the results of NO reduction with single-pair electrode tip discharge plasma also have the same instructive meaning to the NO reduction with multi-pair electrode tip discharge plasma. The amount of both active N atom and NO removal rate increased with the distance /g increasing between the two electrode tips and then dropped when the distance exceeded a certain value. The NO removal rate increased while the voltage between two electrode tips or the resident time of gas flow increased. The distance is a key geometrical variable factor that can determine the intensity of electric field between two electrode tips and the resident time of gas. In this paper, the effects of the dielectric features on NO reduction using dielectric-barrier discharge plasma system were also studied. The results of NO removal rate with different dielectrics such as Al2O3, CaO. MgO and glass showed that the electric field intensity is different with different dielectric, because it brings different energy to particles in discharge room and thus it causes different NO removal rate.     

2,6-二氨基蒽醌/石墨烯复合电极强化电吸附Pb2+

电吸附高效去除水中重金属离子的关键在于开发性能优异的电极材料.采用2,6-二氨基蒽醌(DA)修饰还原氧化石墨烯(r GO),通过溶剂热法成功制备了DA@rGO复合电极,考察了复合电极的电化学性质及电吸附Pb~(2+)性能.循环伏安测试表明,复合电极电化学性质优异,比电容在电流密度为1 A·g-1时达到304. 4 F·g-1,DA修饰显著提高了复合电极的赝电容.电吸附Pb~(2+)测试表明,施加电压为-1. 2 V时电吸附效果最优,反应60 min后Pb~(2+)去除率达94. 8%.电吸附过程符合一级动力学方程,Langmuir模型拟合得到Pb~(2+)的饱和吸附量为356. 66 mg·g-1,明显高于r GO电极(319. 40 mg·g-1),DA修饰引起的电容增加是复合电极Pb~(2+)吸附量提高的重要原因.使用0. 5 mol·L-1硝酸处理可使电极吸附的Pb~(2+)在5 min内脱附完全,实现吸附剂再生.经过10次电极吸附-脱附循环后,DA@rGO复合电极对Pb~(2+)的吸附去除率保持在88%左右,电极循环性能稳定.     

水体环境中氟化物的测定方法研究

利用离子选择电极法和离子色谱法,比较测定了饮用水、景观水及地表水水体中氟化物的含量,发现对污染程度不同的水体两种方法表现出不同的优势,可以指导分析人员根据水体污染程度选择相应的检测方法。     

电化学传感法测定水中亚硝酸盐

借助于简单可控的在线电聚合方法,溴酚蓝被修饰到玻碳电极表面,制备了聚溴酚蓝修饰玻碳电极。实验表明,聚溴酚蓝薄膜对于亚硝酸盐的电化学氧化具有很好的催化作用。经实验优化,聚溴酚蓝膜的最佳厚度为聚合20圈,最佳的检测底液为pH=4.0的0.01 mol/L磷酸盐缓冲溶液。亚硝酸盐在传感器上的电化学氧化是一个双电子双质子参与的过程。在最佳检测条件下,亚硝酸盐的氧化峰电流与其浓度在0.02~109.1μmol/L范围内有良好的线性关系,检测限低至5 nmol/L(S/N=3),所制备的亚硝酸盐传感器线性范围宽、检出限低、稳定性和重现性好、抗干扰能力强,将传感器应用于东湖水样中亚硝酸盐含量的测定,结果令人满意。     

阳极溶出伏安法中电极体系的安装与使用

电极是完成阳极溶出伏安法分析测试的关键。本文就其电极的选择、处理、使用、维护等作了较详细的说明,以保证获得准确的测定数据     

磷酸—磷酸氢二钠法测定尿、血液中的碘元素

尿、血液中碘的测定前处理方法很多,本法用磷酸—磷酸氢二钠离子强度缓冲液加抗坏血酸分解样品,无需分离,在ｐＨ２的条件下用碘离子选择电极直接浓度直读法测定尿、血液中的碘。本法检出限为１０μｇ·ｍｌ－１,标准偏差为０３５０μｇ·ｍｌ－１,精密度为３５８％,具有简便、快速等特点。     

水中痕量苦味酸PVC膜离子选择性电极的研究

本文用苦味酸溴代十六烷基吡啶离子对作为电活性物质,以邻苯二甲酸二辛酯为增塑剂,研制成以ＰＶＣ为基质膜的苦味酸离子选择电极。苦味酸离子浓度在４０×１０－６～１０×１０－１Ｍ范围内,电极电位服从于Ｎｅｒｎｓｔ方程,线性响应级差为－５８０ｍＶ／Ｐ苦味酸,在ｐＨ＝３０～１０５时电极不受ｐＨ影响,苦味酸离子浓度≥４０×１０－６Ｍ时电极电位的标准偏差小于０９９ｍＶ。测定了电极对硝酸根等干扰离子的选择性系数,仅２,６二硝基酚、２,４二硝基酚和钼酸根的选择性系数大于１０×１０－２。     

氧化法处理水中酚的研究方法综述

目前氧化法处理含酚废水的方法有化学氧化法即臭氧氧化法、Fenton试剂氧化法等，酶催化氧化法以及光化学氧化法即光敏化氧化、光催化氧化法等；分析了它们的优势及存在的问题；并提出了今后的研究方向，即臭氧-生物活性炭、臭氧辐射、臭氧-H2O2技术，水溶性酶制剂连接到固体载体上制成固化酶，H2O2－BAC、O3－H2O2－BAC联用技术等。     

单原子环境催化研究进展

单原子催化剂不仅实现了对金属原子最大化利用,而且具有较高催化活性和选择性,还是理想的催化理论研究位点,近年来引起了广泛关注。环境催化在环境保护和污染修复中扮演着重要的角色。单原子催化剂在环境催化领域越来越受关注并有望应用于解决环境问题。单原子催化剂研究的重点和难点集中在单原子催化剂可控合成和催化位点分析表征。为推进单原子催化剂在环境催化领域中的应用,本文综述了单原子的主要制备方法和常规表征手段以及单原子催化剂在环境催化中应用的典型案例,并对单原子催化剂在环境催化中的应用将面临的挑战进行了展望。     

Use of catalytic wet air oxidation (CWAO) for pretreatment of high-salinity high-organic wastewater

Catalytic wet air oxidation (CWAO) coupled desalination technology provides a possibility for the effective and economic degradation of high salinity and high organic wastewater. Chloride widely occurs in natural and wastewaters, and its high content jeopardizes the efficacy of Advanced oxidation process (AOPs). Thus, a novel chlorine ion resistant catalyst B-site Ru doped LaFe_1-xRu_xO_3-δ in CWAO treatment of chlorine ion wastewater was examined. Especially, LaFe_0.85Ru_0.15O_3-δ was 45.5% better than that of the 6%RuO₂@TiO₂ (commercial carrier) on total organic carbon (TOC) removal. Also, doped catalysts LaFe_1-xRu_xO_3-δ showed better activity than supported catalysts RuO₂@LaFeO₃ and RuO₂@TiO₂ with the same Ru content. Moreover, LaFe_0.85Ru_0.15O_3-δ has novel chlorine ion resistance no matter the concentration of Cl⁻ and no Ru dissolves after the reaction. X-ray diffraction (XRD) refinement, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and X-ray absorption fine structure (XAFS) measurements verified the structure of LaFe_0.85Ru_0.15O_3-δ. Kinetic data and density functional theory (DFT) proved that Fe is the site of acetic acid oxidation and adsorption of chloride ions. The existence of Fe in LaFe_0.85Ru_0.15O_3-δ could adsorb chlorine ion (catalytic activity inhibitor), which can protect the Ru site and other active oxygen species to exert catalytic activity. This work is essential for the development of chloride-resistant catalyst in CWAO.

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