Performance of Dielectric Barrier Discharge Reactors on Elemental Mercury Oxidation in the Coal-Fired Flue Gas

The oxidation of elemental mercury （Hg~） by dielectric barrier discharge reactors was studied at room temperature, where concentric cylinder discharge reactor （CCDR） and surface discharge plasma reactor （SDPR） were employed. The parameters （e.g. Hg^0 oxidation efficiency, energy constant, energy yield, energy consumption, and O3 concentration） were discussed. From comparison of the two reactors, higher Hg^0 oxidation efficiency and energy constant in the SDPR system were obtained by using lower specific energy density. At the same applied voltage, energy yield in the SDPR system was larger than that in the CCDR system, and energy consumption in the SDPR system was much less. Additionally, more 03 was generated in the SDPR system. The experimental results showed that 98% of Hg^0 oxidation efficiency, 0.6 J·L^-1 of energy constant, 13.7 μg·J^-1 of energy yield, 15.1 eV·molecule^-1 of energy consumption, and 12.7 μg·J^-1 of O3 concentration were achieved in the SDPR system. The study reveals an alternative and economical technology for Hg^0 oxidation in the coal-fired flue gas.     

特高压输电工程大气环境效益分析

特高压输电是我国消纳清洁能源,降低化石能源消费比重,控制温室气体排放的关键环节,也是治理中东部地区大气污染的重要举措,被列入国家大气污染防治计划。为量化评估特高压输电工程的环境效益,基于火力发电各污染物及其排放、传输特性分析,提出了大气污染物和温室气体减排效益的评估方法。烟尘、SO2、NOx是局部区域性污染物,其减排效益可以只计算受端区域的减排量。重金属汞的减排效益,只计算单质汞Hg0的减排量。单质汞和温室气体CO2是全局性污染物,其减排量等于特高压工程所输送的电力在受端生产和送端生产的排放量之差。受端区域CO2排放因子可依据CDM约定,采用电量边际排放因子OM和容量边际排放因子BM加权计算。送端区域排放因子依据上网电量中火电所占比例和送端区域火电机组基准线排放因子计算。给出前述各环境因子的减排量计算公式。计算了锡盟—山东1 000k V特高压交流输电工程的环境改善效益,可以使山东区域减排烟尘3 156 t/a,SO213 413 t/a,NOx19 331 t/a,全国减排CO2905万t/a。     

气相沿面放电等离子体反应器降解水中对硝基苯酚的研究

采用气相沿面放电等离子体反应器降解水中对硝基苯酚(PNP).考查了载气流量、氧气体积含量和溶液初始pH值对PNP降解效果的影响.结果表明:PNP的降解率随着载气流量的增加而增加,当载气流量增加到1.50 m3/h时,PNP的降解率可达90％以上;载气中氧气体积含量为41％时,PNP降解率为99％;pH值为弱碱性时,PN...     

生物炭对土壤中释放的石油类污染物的吸附

为探究不同来源生物炭对土壤释放到水中石油烃的吸附性能,选取麦秆炭、椰壳炭、稻壳炭和棉秆炭作为吸附剂。通过批量吸附实验,分别考察反应时间、生物炭投加量、pH值和溶液初始浓度对生物炭吸附石油烃性能的影响,并进行动力学和等温吸附拟合。结果表明：4种生物炭均有较高的比表面积,麦秆炭最大,达到729.12 m2/g。当溶液pH值为5、溶液初始质量浓度125.64 mg/L、稻壳炭投加量40 mg、其他生物炭投加量20 mg、反应5 h时,生物炭对石油烃的吸附效果达到最佳状态。4种生物炭对石油烃的吸附能力大小依次为麦秆炭、椰壳炭、稻壳炭、棉秆炭。准二级动力学模型能更好地描述4种生物炭的动力学过程,结果表明生物炭对石油烃的吸附为表面吸附和内部扩散等多种方式;Freundlich模型能够更好地反映等温吸附过程,结果表明生物炭对石油烃为多分子层吸附。