新开发的烟气脱硫方法——MN法

MN法是成都科技大学化工系近年来在实验室开发研究的一种新的烟气脱硫方法。具有净化剂完全循环使用、无抛弃物、无二次污染,设备处理能力大、能耗特别低等特点。该法系将一定浓度的MN浆液与烟气在三相反应器内及常温下接接触,使MN与SO_2反应生成MN的亚硫酸盐固体物。经过物理分离后在100多度的温度下将此种固体物分解成MN部SO_2,达到循环使用MN和回收SO_2的目的。SO_2可以制成希望的产品。实验表明,在处理含SO_21000～3500ppm的烟气时,一次脱硫率>95％,硫回收率>90％,处理后的排放气中含硫<50     

超低排放CEMS样气预处理系统优化

样气预处理产生的冷凝水会吸收样气中SO_2,逃逸氨在预处理过程中与SO_2发生化学反应,对样气中SO_2进行二次吸收,造成CEMS检测SO_2偏低。特别是超低排放限值标准下,损失率会更大。文章以氨法脱硫装置的热抽取式CEMS系统为研究对象,通过在样气预处理中增加动态磷酸滴定和Nafion管,有效解决CEMS系统中冷凝水、逃逸氨对样气中SO_2吸收的问题。     

SO2对农作物影响及敏感生理生化监测指标筛选

利用田间开顶式熏气装置对油菜、水稻、红薯3种农作物进行SO_2急性伤害实验,研究不同浓度SO_2对受试农作物生理生化指标的影响。结果表明:熏气可造成农作物的急性伤害,导致农作物生理生化指标发生大幅度变化。在熏气处理后,3种农作物的叶片含硫量、细胞膜透性均明显增加,与处理浓度存在显著线性正相关;可溶性蛋白含量明显降低,与处理浓度存在显著线性负相关;过氧化氢酶及超氧化物歧化酶活性与处理浓度没有显著相关性;可选择叶片含硫量、细胞膜透性、可溶性蛋白作为监测SO_2对农作物急性伤害程度的敏感指标。     

大型燃煤电厂“前端”烟气SO_3控制技术

由于SCR脱硝的大规模应用,尽管脱硫实施超低排放之后SO_2得到有效控制,但烟气中的SO_3浓度反而成倍增长,尤其在燃用高硫煤的电厂,烟囱SO_3远远超过SO_2的排放水平。烟气中的SO_3浓度过高,会引起大气环境污染,并严重影响电厂机组的正常运行和经济运行。文章以西南地区某电厂2×600MW机组为例,介绍了燃煤电厂烟气SO_3的形成及危害,硫酸氢铵ABS的形成,"前端"烟气SO_3脱除技术原理,重点阐述"前端"烟气SO_3脱除产生的协同经济效益。对今后同类机组烟气SO_3的控制具有参考和借鉴作用。     

Ti/PbO2电极与Ti/IrO2+Ta2O5电极催化体系降解酸性大红染料废水的比较研究

为比较Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系降解酸性大红(GR)染料废水的处理效果,并确定体系最佳工艺参数。分别对Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系内初始pH、染料初始浓度、电流密度、电解质浓度对GR染料降解率的影响进行了探索,比较工艺参数优化后两催化体系的GR降解率、电极形貌及TOC去除率。结果表明,工艺参数优化后(初始pH 6.38,染料初始浓度100 mg/L,电流密度50 mA/cm²,电解质浓度0.1 mg/L),Ti/PbO₂电极和Ti/IrO₂+Ta₂O₅电极催化体系GR去除率分别可达98.3%和61.1%,TOC去除率为25.4%和13.5%;结合电极表面形貌分析,Ti/IrO₂+Ta₂O_5<...     

乌鲁木齐大气污染物变化特征及综合评价

随着经济发展和城市化速度加快,大气污染已经成为区域性环境问题,基于2001～2018年乌鲁木齐市城市空气质量监测数据,选取SO_2、NO_2、PM_(10) 3种常规大气监测污染物作为乌鲁木齐大气环境体系评价指标,利用AHP层次分析法,建立大气污染物层次构造模型,对乌鲁木齐市大气环境质量作出综合评价。结果表明:乌鲁木齐市大气2001～2014年期间环境质量为三级,2015～2018年环境质量为二级,大气污染物权重排序为:煤改气前PM_(10)SO_2NO_2,煤改气后PM_(10)NO_2SO_2,说明乌鲁木齐市大气颗粒物占主要作用,"煤改气"能源结构调整使SO_2的浓度也有所降低,大气污染类型从以前的煤烟型污染向复合型污染逐渐转化。各年度大气质量优劣依次为2014～2018呈现逐年变好的趋势,2001～2013年有升高也有降低交替存在,整体评价与乌鲁木齐市环境质量状况公报公布的一致。表明大气环境质量改善趋势较明显,研究成果为探索乌鲁木齐市大气环境治理提供重要依据。     

石灰石-石膏湿法烟气脱硫效率影响因素

从石灰石-石膏湿法烟气脱硫工艺的流程、基本原理,研究了脱硫效率的影响因素:石灰石浆液pH值、钙硫比、液气比、吸收塔进口粉尘含量、烟气中SO_2浓度、烟气含氧量等烟气脱硫工艺条件对脱硫效率的影响。根据上述研究结果,从工艺及设备运行角度探讨如何控制适宜的工艺条件,优化提高石灰石-石膏湿法烟气脱硫工艺的脱硫效率,使烟气中SO_2排放浓度控制在25 mg/m~3左右,达到GB 13223—2011《火电厂大气污染物排放标准》中SO_2小于200 mg/m~3的排放标准。     

降低SnO2基CO气敏材料工作温度的方法

本文简要说明了SnO2的结构及其对CO的气敏原理。针对SnO2基CO气敏材料工作温度较高、能耗较大的缺点，提出了降低其工作温度的几种方法：扩大比表面积、掺入适当的杂质和添加适当的催化剂。     

填料塔胺法脱硫实验研究

建立了填料塔胺法脱硫实验装置,以乙二胺/磷酸溶液为吸收剂,通过条件实验,考察了操作参数对SO_2吸收率的影响。结果表明:脱硫率随液气比、填料层高度的增加而增大,随空塔气速、气相入口SO_2浓度及吸收贫液中四价硫S(IV)浓度的增大而减小,其中,空塔气速和贫液S(IV)浓度对吸收率的影响显著;实验条件下,吸收液气比不宜低于1.73L/m3,贫液S(IV)浓度宜控制在0.1mol/L以下;增大吸收液流量或降低贫液S(IV)浓度均会降低液相传质阻力。     

“填料＋丝网”除雾在氨法脱硫的工业应用

为解决"烟气拖尾"、烟囱雨、气溶胶等问题,克拉玛依石化公司动力厂在燃煤锅炉上采用氨法双塔脱硫工艺技术,经过浓缩塔后的烟气在吸收塔内先经过三级浆液喷淋逐步降低SO_2的浓度,后经"填料+丝网"除雾消除气溶胶。装置投用后,脱硫效率达到98%以上,出口SO_2小于30 mg/m~3,烟尘小于10 mg/m~3,达到了《全面实施燃煤电厂超低排放和节能改造工作方案》中SO_2不大于35 mg/m~3,烟尘不大于10 mg/m~3超低排放要求。     

Removal of o-nitrophenol from water by electrochemical degradation using a lead oxide/titanium modified electrode

This study examined o-nitrophenol removal from aqueous solutions by electrochemical oxidation employing a modified electrode. The modified electrode was produced by electrodepositing lead oxide onto a titanium substrate. Following electrochemical oxidation of o-nitrophenol-containing solutions, the remaining o-nitrophenol concentration and chemical oxygen demand (COD) values were determined. The optimum parameters were current density of 40 mA cm(-2), pH of 2.47, 60 min of electrolysis time, 4 g L(-1) NaCl electrolyte solution and temperature of 30 degrees C. Under these optimum conditions of electrochemical degradation using a lead oxide/titanium modified electrode complete removal of o-nitrophenol and COD was achieved.     

The use of electrolyte redox potential to monitor the Ce(IV)/Ce(III) couple

Mathematical modelling of the oxidation reduction redox potential (ORP) of an electrolyte has been carried out for a batch system comprising an electrochemical reactor and an electrolyte circuit containing a redox couple. The ORP can be useful to monitor the environmental impact of chemical species in solution that represent a risk to the environment. Considerations of four fundamental equations, namely, the Nernst equation, a mass balance, Faraday's laws of electrolysis and a first order kinetic equation, leads to an expression for the electrolyte redox potential as a function of the batch time, the electrical charge and the redox concentration. Such an expression facilitates graphical plots which can be used to estimate kinetic parameters, current efficiency and the relative redox concentration. The Ce(IV)/Ce(III) system has been chosen as a model reaction for electrolyte redox potential measurement in a batch recycle system consisting of a pumped flow through a divided FM01-LC parallel-plate electrochemical reactor (64cm(2) projected electrode area) and a well mixed tank (3600cm(3)). The differences between experimental and model predictions are discussed.     

Novel electrochemical half-cell design and fabrication for performance analysis of metal-air battery air-cathodes

Metal-air batteries (MABs) are considered promising candidates for sustainable energy storage & conversion applications. Air-cathodes have been identified to be the major challenge towards the commercialization of MAB technology. In development of air-cathodes effectively, a method, or a device is desired for cathode evaluation at operating conditions that are as close as possible to that of an actual battery. In this paper, for diagnosing, evaluating and analyzing the electrochemical performance of MAB air-cathodes, a novel electrochemical half-cell has been designed and fabricated. This half-cell is a three-electrode system, in which the air-cathode is used as the working electrode, a platinum wire with large area as the counter electrode and a saturated calomel electrode (SCE) as the reference electrode. The working electrode is designed to allow the surface of gas diffusion layer to be exposed to the air and the catalyst layer to be exposed to the electrolyte. This half-cell is validated by commercially available and in-house made air cathodes using electrochemical linear scan voltammetry (LSV) method in both neutral and alkaline solutions at various temperatures, enabling the in-situ performance evaluation and analysis of air-cathodes in an environment much closer to that of a primary aqueous metal-air battery while offering a more controlled laboratory environment and economic way for down-selecting and optimizing the air-cathodes.     

提高化学需氧量质控合格率的研究

大庆油田化工总厂废水中化学需氧量（COD）的测定采用库仑法。为了提高质控合格率，从人员素质、仪器设备、电级内液等9个方面分析寻找导致误差的主要影响因素并制定对策。同时对影响电极内液及消解的因素进行正交实验确定最佳条件。结果使库仑法质控合格率由90％提高到95％，测定38次标样全部合格。     

Electrocoagulation of palm oil mill effluent as wastewater treatment and hydrogen production using electrode aluminum

Palm oil mill effluent (POME) is highly polluting wastewater generated from the palm oil milling process. Palm oil mill effluent was used as an electrolyte without any additive or pretreatment to perform electrocoagulation (EC) using electricity (direct current) ranging from 2 to 4 volts in the presence of aluminum electrodes with a reactor volume of 20 L. The production of hydrogen gas, removal of chemical oxygen demand (COD), and turbidity as a result of electrocoagulation of POME were determined. The results show that EC can reduce the COD and turbidity of POME by 57 and 62%, respectively, in addition to the 42% hydrogen production. Hydrogen production was also helpful to remove the lighter suspended solids toward the surface. The production of Al(OH)XHO at the aluminum electrode (anode) was responsible for the flocculation-coagulation process of suspended solids followed by sedimentation under gravity. The production of hydrogen gas from POME during EC was also compared with hydrogen gas production by electrolysis of tap water at pH 4 and tap water without pH adjustment under the same conditions. The main advantage of this study is to produce hydrogen gas while treating POME with EC to reduce COD and turbidity effectively.     

Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr and daminozid in aqueous suspensions of titanium dioxide

Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr (1) and daminozid (2), has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing the UV Spectroscopic analysis technique and depletion of Total Organic Carbon (TOC) content as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and catalyst concentration, different types of TiO2 and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate (NH4)2S2O8 in addition to molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient as compared with other photocatalysts. The pesticide derivative triclopyr (1) was found to degrade faster as compared to daminozid (2). An attempt was also made to identify the intermediate products formed during the photooxidation process using GC/MS analysis. Probable pathways for the formation of products have been proposed.     

各类固体表面处理及改性进展

表面改性,即对固体的表面进行处理,改变其表面性质,以达到我们需要的理想结果。研究表面性质的方法就是引入某种“探针”考察它与表面的相互作用,通过这种方法对改性前后的样品进行表征。现以催化剂载体表面、电极材料表面及塑料表面为例对表面改性的最新研究进展进行概述。     

纳米TiO2膜阳极在丁二酸电解合成上的应用

研究了以钛酸四丁酯为原料制备纳米TiO2膜电极的方法，并使用纳米TiO2膜电极作电解阳极，以铅板作阴极，在顺丁烯二酸还原为丁二酸的电解装置中运用，结果产品的收率和电流效率较高，极板的使用寿命长，并且减少了环境污染和劳动强度。     

浅析篮球训练和比赛中合理补水的重要性

在篮球训练和比赛中,运动员丢失大量的汗液,使机体内水、电解质平衡紊乱.因此,运动前、中、后的合理补水对保持体内水和电解质的平衡,提高耐力,延迟疲劳的出现,从而提高运动能力非常重要.     

Adsorption of cadmium, copper, nickel, and zinc to a poly(tetrafluorethene) porous soil solution sampler

Suction cups made of poly(tetrafluorethene) (PTFE) are widely used for sampling of soil solution. A brand (Prenart) of PTFE cups was tested for adsorption of Cd, Cu, Ni, and Zn at low concentrations under different conditions. In a laboratory experiment adsorption from a 10 microg L(-1) heavy metal solution with a 0.01 M NaCl background electrolyte was investigated at pH 3.6, 4.5, and 5.8 by pumping the solutions through the cups. The effect of three different ionic compositions was also investigated using 0.01 M CaCl2, 0.01 M NaCl, and no background electrolyte at pH 4.5. In 0.01 M NaCl electrolyte at pH 5.8 the cups acted as effective filters. At pH 3.6 after 300 mL of solution had passed through the cup, equivalence between the Cd and Ni concentrations in influent and effluent was found. No equivalence between effluent and influent concentrations was found for Zn and Cu at pH 4.5 and 5.8. With Ca as the electrolyte, no adsorption of Cd, Ni, or Zn was found. In Na electrolyte, equivalence between influent and effluent concentrations for Cd, Ni, and Zn was reached. The difference between effluent and influent concentrations of Zn, Ni, and Cd remained significant in the absence of electrolyte. For all pH values and electrolytes the difference between effluent and influent concentrations of Cu was significant. It is concluded that PTFE cups affect the concentrations of heavy metals sampled at low soil solution concentrations. Cadmium, Cu, Ni, and Zn adsorb to the cup at pH > 4.5 and low ionic strength.