《环境科学导论》课程的教学与实践

《环境科学导论》是厦门大学的一门省级精品课程,在课程的建设过程中,通过课程组全体教师的不懈努力,逐渐形成了一套有自我特色的教学风格,并在教学方法与手段等方面进行了有益的探索与实践

Effect of Various Fly Ash Compositions on Mercury Speciation Transformation

以厦门嵩屿燃煤电厂第一电除尘机组前采集的飞灰为样品,筛选出不同粒径的飞灰,采用X射线衍射对样品进行成分检测。建立模拟烟气实验台,采用OnTArIO HydrO方法作为检测方法,对不同粒径、飞灰成分、烟气组分条件下,烟气中影响汞氧化的因素进行实验研究。结果表明:飞灰的成分主要包括Al2O3、SIO2、MgO、CAO、fE2O3,飞灰各组分对汞的氧化都具有促进作用,效果较为明显的是Al2O3和CAO。分析大中小3种粒径对汞氧化的影响,得出大粒径飞灰更能促进汞的氧化。同时也验证了气体组分中O2和HCl对汞氧化的促进作用。Fly ash samples were derived from the 1st electrostatic precipitators of Songyu power plant in Xiamen,and different particle sizes of samples were screened out,the compositions of fly ash has been studied with X-ray fluorescence spectrometry.Using Ontario Hydro method for mercury speciation testing,a bench-scale testing apparatus was constructed to study the effect of various fly ash compositions on mercury speciation transformation.The conclusions are as follows: The main compositions of fly ash are: Al2O3,SiO2,MgO,CaO and Fe2O3,all of them could enhance oxidation of Hg,especially Al2O3 and CaO.The size of fly ash has impact on the mercury transformation,and the conversion ratio of Hg2+ to total Hg increased with increasing the size of fly ash sample.Experiment results show that O2 and HCl can greatly promote the mercury oxidization.国家自然科学基金项目(20707018);福建省科技重点项目(2008I0024);福建省青年人才项目(2006F3118)---

Study on the Mercury Emission From Seawater for Coal-fired Flue Gas De-sulphurization During Aeration Process

作为湿法脱硫工艺的吸收剂,海水在去除烟气中SO2的过程中,也能吸收烟气中的二价汞,但在恢复水质的曝气过程中,已吸附在海水中的二价汞易释放出来。该文采用金丝捕汞法富集曝气池上空大气中的汞,同时采集曝气池海水水样,考察不同运行工况下脱硫海水中的汞向大气释放的浓度水平及变化趋势。结果表明:曝气池上空总气态汞(TOTAl gASEOuS MErCury,TgM)的浓度平均值为10.01ng/M3,高出当地背景值的20倍以上。曝气池上空TgM浓度与池中海水的汞浓度、曝气强度呈正相关性。TgM浓度在白昼时段高于夜间时段,并在中午日光照射较强的时段出现峰值,表明光致还原对曝气池海水中汞的释放起到了重要的促进作用。研究结果有利于评价海水脱硫工艺的环境风险及其对局部区域大气质量的影响。As the absorbent of wet flue gas desulphurization(FGD) technology,seawater can dissolve oxidated mercury during the process of the removal of SO2 in flue gas,but in the process of aeration for the quality improvement of seawater,the mercury dissolved in seawater is inclined to release again.The method of gold amalgamation was employed to sample total gaseous mercury(TGM) in the air above the aeration sink,and the seawater in sink was also sampled to study the concentration and trend of mercury emitted from the aeration sink for the seawater-FGD in different operation conditions.The results showed that the average concentration of TGM was about 10.01 ng/m3,which was 20 times higher than that of local background,and it presented a positive correlation with mercury concentrations in seawater of the FGD system and aeration intensity.The experiment also found that the TGM concentrations in daytime,especially during noon time,were higher than those at night,which could be explained by that the photo-reduction played an important role on mercury emission from seawater in the aeration sink.The result of experiment is in favor of evaluating the environmental risk and the impact on local air quality caused by seawater FGD technology.中国科学院知识创新工程重要方向项目(KZCX2-YW-422-4

Retrospect and Outlook on Utilization of Fly Ash

介绍了粉煤灰的物理化学性质和结构,从不同角度分析了粉煤灰的应用情况及存在的问题,并对粉煤灰潜在的综合利用途径进行了探讨和展望,以期为粉煤灰的合理有效利用提供可行依据。Physical and chemical characteristics and structure of fly ash were introduced. Utilization situation and existing problems of fly ash were analyzed from different perspectives. And potential approaches of integrated utilization of fly ash were discussed to provide feasible basis for reasonable and effective application of fly ash

Control Technologies and Evaluation of Mercury in Flue Gas of Waste Incineration

介绍了当前垃圾焚烧烟气中汞形态分布,对利用现有设备脱汞、nA2S喷射、吸附剂捕集等方法在烟气脱汞运用中的优缺点进行分析,建立实验室规模的活性炭吸附-脱附系统,对比氮气氛围不同活性炭对气态汞的吸附性能,以更好地控制垃圾焚烧烟气中气态汞的排放行为。The mercury speciation distribution in flue gas of waste incineration was introduced.The advantages and disadvantages of different ways on mercury controlling were analyzed,including using the existing equipment,Na2S injection and sorbent trapping.A laboratory-scale activated carbon adsorption-desorption system was developed,and the adsorption properties of different activated carbon in nitrogen atmosphere were compared to control gaseous mercury in flue gas of waste incineration

Experimental Study on Modified Activated Carbons for Elemental Mercury Adsorption

在小型固定床实验台上对中孔分子筛(SbA-15)、煤基活性炭(bPl)、不同含水量活性炭、苯酚和苯甲酸改性活性炭进行气态汞的吸附实验。结果表明:相对于中孔而言,微孔更有利于气态汞的吸附。负载羧基样品对气态汞的吸附能力与原始活性炭相比有很大提高。当羧基负载量为28.89Mg羧基/g活性炭时,样品对气态汞的吸附性能达到最佳;经酚羟基改性样品,其对气态汞的吸附能力显著降低,当达到吸附饱和时,原始活性炭的吸附量为306.55μg/g,而酚羟基改性样品最大吸附容量为133.1μg/g,且负载量与气态汞吸附量呈负相关,由此推测酚羟基对气态汞的吸附没有促进作用,而羧基有利于气态汞的吸附。活性炭表面存在适量水分有利于气态汞的吸附,当样品表面含水率为14.49%时,样品的吸附性能达到最佳。A laboratory-scale packed-bed reactor system was used to evaluate the capability of mesoporous molecular sieve(SBA-15),coal-based activated carbon(BPL),activated carbons containing different content of moisture,phenol-modified and carboxyl-modified activated carbons for mercury adsorption.The results show that compared to the mesopore structure,micropore structure on the surface of activated carbons is in favor of capturing mercury from carrier gas.The mercury adsorption capacity of carboxyl-modified activated carbons increases significantly compared to that of original carbons.And the best result obtained at the modification ratio of 28.89 mg carboxyl groups /g activated carbon.While the capacity of phenol-modified activated carbons for mercury adsorption decreases remarkably.When reaches saturation,the mercury adsorption capacity of original activated carbons is 306.55 μg/g,while the highest capacity of phenol-loaded activated carbons is 133.1 μg/g,and there is a positive relation between the amounts of phenol or carboxyl and mercury adsorption.It suggests that the phenol groups may have no effect on mercury adsorption,while the carboxyl groups are beneficial to the mercury adsorption.The presence of moisture on the surface of activated carbons can enhance their mercury adsorption capacities,and when the moisture content is 14.49%,the adsorption capacity reaches the best result.国家自然科学基金项目(20707018);福建省科技重点项目(2008I0024);福建省青年人才项目(2006F3118)---

The Atmospheric Mercury Pollution Survey During Autumn and Winter Seasons in Xiamen

文章采用两次金汞齐-冷原子荧光光谱法对厦门地区秋冬季节大气汞的污染状况作了初步调查分析,结果表明厦门地区大气中汞的浓度平均为11.037 ng/M3,其含量高于北半球大气气态总汞含量的背景值(1.5--2.0 ng/M3),表明该地区已受到一定程度的大气汞污染;在一定的采样区域,大气汞浓度与温度、太阳辐射量、大气压、空气湿度成正相关,与风速成负相关;气态汞的含量在80%左右,这与该地区的人为活动多有关,与其他地区报道的类似区域情况的汞污染状况相符;工业区,学校实验室周边区域,生产过程中以汞为原料的工厂等附近区域,大气中汞的含量较高,开阔区域的海边含量较低,交通繁忙区域最低(所选采样点与交通要道有一定的距离),这种浓度分布说明了大气中汞的存在具有区域性特征。In this paper,the atmospheric mercury pollution during autumn and winter seasons in Xiamen was analyzed with the method of two-stage gold amalgamation-cold vapor atomic fluorescence spectroscopy.The results show that the average concentration of atmospheric mercury in Xiamen is 11.037ng/m3,which is higher than the background value(1.5ng/m3--2.0ng/m3) of the atmospheric mercury in the northern hemisphere.It indicates that there is a certain degree of mercury pollution in Xiamen.there is a positive relationship between mercury concentration and temperature、solar radiation、atmospheric pressure and humidity,while there is a negative relationship between mercury concentration and wind speed.The content of gaseous mercury in Xiamen is about 80%,which shows analogous level compared to the mercury concentration in other areas.The high content of gaseous mercury in Xiamen maybe related to the human activities.The mercury concentration is high in some regions such as industrial zone,areas around school laboratories,factories which use mercury as raw materials,while the mercury concentration is a little lower in the open area of the seaside,and the mercury concentration is the lowest in traffic busy areas(there is some distance between sampling locations and traffic busy in this study).The distribution of mercury concentration indicates that there is a regional character of atmospheric mercury in Xiamen

垃圾焚烧飞灰酸洗废水的处理技术研究

介绍垃圾焚烧飞灰酸洗废水的来源及危害,综述酸洗废水的处理技术,重点介绍了化学沉淀和物理化学处理手段。并对某垃圾焚烧电厂飞灰酸洗废水进行硫化物沉淀试验研究,讨论药剂投加量、PH值、重金属浓度对沉淀效果的影响

二次酸洗工艺对垃圾焚烧飞灰重金属脱除效果的影响研究

以某垃圾焚烧电厂采集的飞灰研究为例,在普通酸洗处理后加入有机酸二次酸洗,分析不同浓度酸液及酸洗时间,对飞灰重金属的洗脱效果影响情况

Effects of flue gas components and fly ash on mercury oxidation

模拟研究O2、SO2和HCl三种烟气气体与飞灰存在状态对汞形态转化的影响,并探讨温度对其转化的作用.结果表明:在不同气氛中,反应温度升高有利于汞的氧化,但n2--SO2的烟气体系则相反;O2、SO2和HCl单独存在于烟气中时,对汞的氧化起到不同程度的促进作用,其中HCl的效果最好;烟气中含有O2和HCl将使汞的氧化率明显提高;当SO2与HCl同时存在于烟气中时,SO2会通过与HCl反应抑制汞的氧化过程.飞灰为氧化反应提供反应介质和催化剂,促进烟气中汞的形态转化.The effects of gas components such as O2,SO2 and HCl,the existence of fly ash,and temperature on mercury speciation were investigated.It is shown that high temperature is positive to mercury oxidation in most of the simulated flue gas system except for the N2-SO2 system.The existence of O2,SO2 and HCl in the system separately improves the oxidation process,and among them HCl performs the best.When both SO2 and HCl are in the system,the oxidation efficiency of HCl decreases due to the reaction between SO2 and HCl.Fly ash provides,reaction media and catalysts for the mercury oxidation reaction,and consequently,the existence of fly ash in the simulated flue gas can increase mercury speciation.国家自然科学基金资助项目(No.20707018);福建省科技重点资助项目(No.2008I0024);中央高校基础业务费资助项目(No.2010121078);厦门市科技计划资助项目(No.3502Z20103014