活性炭纤维生物挂膜脱除硫化氢

生物脱硫法作为一种高效、高实用性的除硫新技术而受到越来越多的关注。以活性炭纤维为微生物载体,通过活性污泥上清液挂膜驯化,考察硫化氢进气量、喷淋量、pH值和硫酸根离子浓度等条件对脱硫效率的影响。研究结果表明,在室温下,硫化氢负荷为90 g/(m3.h),进气浓度控制在3 g/m3,进气量为60 L/h,喷淋量为250～650 L/(m3.d),pH为2～5的条件下,生物活性炭纤维对硫化氢的去除率可保持在98%以上。     

活性炭吸附硫化氢及微波辐照解吸研究

研究了两种活性炭对硫化氢的平衡吸附性能力,并对活性炭床层的穿透性进行了考察;吸附饱和和活性炭在微波辐射的作用下进行解吸。实验表明,解吸效率与微波作用时间及温度有关,在本实验条件下H2S解吸效率达90．1％。     

Diffusion of hydrogen sulfide and methyl mercaptan onto microporous alkaline activated carbon

Activated carbon kinetic studies show that both H2S and CH3SH yielded pore diffusion coefficients from 10(-6) to 10(-8) cm2/s. Results indicated that pore structures could influence effective diffusivity. Under the same adsorbate concentration, CH3SH exhibited a greater effective pore diffusion coefficient than H2S. This may be attributed to the fact that CH3SH has both polar (-SH) and non-polar (-CH3) functional groups and dissolves into water easier, thus providing more attraction for the activated carbon surface. In addition, the saturation vapor pressure of CH3SH is lower than that of H2S. Therefore, CH3SH is easier to adsorb onto activated carbon than H2S.     

活性炭纤维对染料的吸附性能研究

研究了聚丙烯腈活性炭纤维（P－ACF）、粘胶活性炭纤维（R－ACF）和颗粒活性炭（GAC）对5种红色染料的吸附能力,通过简单的模型,算出5种染料在两种活性炭纤维上的吸附速率常数。结果表明,尽管吸附能力随染料种类不同而有一定的差别,但总体上,聚丙烯腈活性炭纤维的吸附能力略低于颗粒活性炭,而粘胶活性炭纤维的吸附能力则远远优于前两种,对染料有着较大的吸附容量和较快的吸附速率。     

Ozone injection into an activated carbon bed to remove hydrogen sulfide in the presence of concurrent substances

Adsorption using activated carbon is one of the most reliable techniques for preventing odor by substances such as H2S. Concurrent substances in effluent gas often reduce the removal capacity of activated carbon for H2S. As a means of restoring capacity under such conditions, ozone injection into an activated carbon column was examined. When activated carbon was saturated with substances such as toluene, ethanol, n-butanol, or iso-butanol, its capacity to remove H2S decreased in proportion to the amount of the saturating substance. Under such conditions, ozone injection greatly increased capacity. Toluene, which is not easily decomposed by ozone, was displaced by ozone and by oxidized products of H2S. Ethanol, which is adsorbed in small amounts by activated carbon and easily decomposed by ozone, was removed by ozone injection. Butanols, which are also decomposed by ozone and adsorbed in large quantities by activated carbon, showed intermediate behavior between that of toluene and ethanol.     

氮改性活性碳纤维的脱硫作用

为了提高活性碳纤维的脱硫性能,使用三聚氰胺、氯化铵、尿素作为改性剂对活性碳纤维进行改性,得到一系列含氮活性碳纤维(N-ACFs).通过XPS研究了改性活性碳纤维的表面化学结构的变化,并测定了其脱硫性能.实验发现:三聚氰胺改性ACF的最大累积硫容为38.26 mg/g,氯化铵改性ACF的最大累积硫容33.69 mg/g,...     

Removal of carbonyl sulfide using activated carbon adsorption

Wastewater treatment plant odors are caused by compounds such as hydrogen sulfide (H2S), methyl mercaptans, and carbonyl sulfide (COS). One of the most efficient odor control processes is activated carbon adsorption; however, very few studies have been conducted on COS adsorption. COS is not only an odor causing compound but is also listed in the Clean Air Act as a hazardous air pollutant. Objectives of this study were to determine the following: (1) the adsorption capacity of 3 different carbons for COS removal; (2) the impact of relative humidity (RH) on COS adsorption; (3) the extent of competitive adsorption of COS in the presence of H2S; and (4) whether ammonia injection would increase COS adsorption capacity. Vapor phase react (VPR; reactivated), BPL (bituminous coal-based), and Centaur (physically modified to enhance H2S adsorption) carbons manufactured by Calgon Carbon Corp. were tested in three laboratory-scale columns, 6 in. in depth and 1 in. in diameter. Inlet COS concentrations varied from 35 to 49 ppmv (86-120 mg/m3). RHs of 17%, 30%, 50%, and 90% were tested. For competitive adsorption studies, H2S was tested at 60 ppmv, with COS at 30 ppmv. COS, RH, H2S, and ammonia concentrations were measured using an International Sensor Technology Model IQ-350 solid state sensor, Cole-Parmer humidity stick, Interscan Corp. 1000 series portable analyzer, and Drager Accuro ammonia sensor, respectively. It was found that the adsorption capacity of Centaur carbon for COS was higher than the other two carbons, regardless of RH. As humidity increased, the percentage of decrease in adsorption capacity of Centaur carbon, however, was greater than the other two carbons. The carbon adsorption capacity for COS decreased in proportion to the percentage of H2S in the gas stream. More adsorption sites appear to be available to H2S, a smaller molecule. Ammonia, which has been found to increase H2S adsorption capacity, did not increase the capacity for COS.     

Direct field observation of the relative humidity effect on the beta-gauge readings

The effect of ambient relative humidity (RH) on hourly particulate matter (PM10) readings of beta-gauge monitors has been studied using two collocated monitors in the field. The inlet air of monitor 1 was conditioned with water vapor to increase its RH, whereas monitor 2 operated normally in ambient conditions. Experimental data showed that PM10 readings of monitor 1 were nearly the same as monitor 2, as long as the RH of its conditioned incoming air did not exceed approximately 80-85%. However, when the RH exceeded approximately 80-85%, PM10 readings of monitor 1 became higher than monitor 2, and the difference increased with increasing RH. The measurement of pressure drop across the filter was also conducted, and the data revealed that the increase of pressure drop per unit of PM10 concentration decreased when RH was higher than approximately 80-85%, as compared with the case when RH was lower than 80-85%. This is perhaps because of more porous structure of deposited particles in the beta-gauge monitor when RH is greater than approximately 80-85%. The theoretical calculation using an evaporation model and a thermodynamic model has been conducted to simulate the beta-gauge readings. The results show that the theoretical PM10 concentrations using the evaporation model are in better agreement with the actual beta-gauge readings than those using the thermodynamic equilibrium model.     

相对湿度对钙基脱硫剂干法烟气脱硫效率的影响

为得到干法烟气脱硫较优的相对湿度,并验证钙基脱硫剂在干法烟气脱硫中的可行性,在模拟干法烟气脱硫实验台上,研究了钙基脱硫剂在不同相对湿度(0~45%)条件下,脱硫剂的出口浓度、脱硫效率和固硫量。结果表明,在相对湿度从0变化至45%时,可以稳定运行的穿透时间由160 min增加到720 min,可达100%脱硫效率的运行时间由0增至580 min,脱硫剂的固硫量从43.37 mg增加到332.09 mg;增加相对湿度能显著提高烟气脱硫效率,在保证烟气不穿透物料且不出现黏壁现象的条件下,较优的相对湿度为45%。研究明确了在低相对湿度条件下此种脱硫剂的可行性并确定了较优化的干法脱硫湿度,为干法脱硫条件的选择提供了参考。     

沙柳活性炭纤维的制备与表征

以（NH4）2HPO4活化沙柳纤维制备活性炭纤维,L16（45）正交实验优化制备工艺条件,重点研究了活化温度对活性炭纤维结构的影响。同时应用扫描电镜（SEM）对其表面形貌进行表征,通过N2吸附-脱附测定其孔结构。结果表明,随着活化温度的升高,活性炭得率逐渐减小,碘吸附值先增大后减小,在浸渍比2.5：1、预氧化温度200℃、预氧化时间90 min、活化温度为800℃、活化时间60 min的条件下,可以制备出比表面积为1 304 m2·g-1、总孔容为1.004 cm3·g-1、得率为31.6%、碘吸附值为1 321 mg·g-1的纤维状活性炭。     

Simultaneous removal of sulfur dioxide and polycyclic aromatic hydrocarbons from incineration flue gas using activated carbon fibers

Incineration flue gas contains polycyclic aromatic hydrocarbons (PAHs) and sulfur dioxide (SO₂). The effects of SO₂ concentration (0, 350, 750, and 1000 ppm), reaction temperature (160, 200, and 280 °C), and the type of activated carbon fibers (ACFs) on the removal of SO₂ and PAHs by ACFs were examined in this study. A fluidized bed incinerator was used to simulate practical incineration flue gas. It was found that the presence of SO₂ in the incineration flue gas could drastically decrease removal of PAHs because of competitive adsorption. The effect of rise in the reaction temperature from 160 to 280 °C on removal of PAHs was greater than that on SO₂ removal at an SO₂ concentration of 750 ppm. Among the three ACFs studied, ACF-B, with the highest microporous volume, highest O content, and the tightest structure, was the best adsorbent for removing SO₂ and PAHs when these gases coexisted in the incineration flue gas.

ImplicationsSimultaneous adsorption of sulfur dioxide (SO₂) and polycyclic aromatic hydrocarbons (PAHs) emitted from incineration flue gas onto activated carbon fibers (ACFs) meant to devise a new technique showed that the presence of SO₂ in the incineration flue gas leads to a drastic decrease in removal of PAHs because of competitive adsorption. Reaction temperature had a greater influence on PAHs removal than on SO₂ removal. ACF-B, with the highest microporous volume, highest O content, and tightest structure among the three studied ACFs, was found to be the best adsorbent for removing SO₂ and PAHs.     

甲苯气体的动态吸附净化及吸附剂再生实验研究

研究了活性炭纤维(ACF)对甲苯气体的动态吸附净化过程及热空气解吸脱附再生过程.采用3种经验方程对ACF的吸附等温线进行拟合,其中Langmuir方程拟合效果最好,拟合相关系数R2 =0.9960,说明在给定的浓度范围内,ACF对甲苯的吸附是以单分子层吸附为主.穿透曲线实验表明,ACF对甲苯吸附效果较好,Yoon-Ne...     

Dynamic NO adsorption characteristics of iron-treated activated carbon fibers

The breakthrough curve for NO adsorption on the activated carbon fibers treated in iron salt solutions was determined. They can adsorb much more NO than granular activated carbon by a factor of more than 10 from a flowing 300 ppm NO-N₂ mixed gas at 100°C and 20 ml min⁻¹; the most effective one of the iron-treated carbon fibers of 0.2 g is able to reduce the NO concentration from 300 ppm to 30 ppm. These adsorbents can adsorb the same amount of NO from even a 300 ppm NO-500 ppm SO₂-10% CO₂-10% H₂O-1% O₂-N₂ mixed gas.     

多层生物滤塔净化硫化氢废气研究

以木屑为填料,采用多层生物滤塔净化H2S气体,研究其适宜的工艺条件及生物降解宏观动力学.结果表明,填料分层可提高H2S去除率,当进气容积负荷＜153.2 g H2S/(m3·d)时,H2S的去除率保持在90%以上;进气浓度低于70 mg/m3,下层200mm填料对H2S总去除率的贡献在50%以上;填料含水率为50%～6...     

碱处理和掺氮耦合改性对活性炭纤维吸附甲醛性能的影响

甲醛作为一种常见的挥发有机化合物（VOC）,对人体健康构成长期危害。为提高活性炭纤维（ACF）对甲醛等有害气体的吸附去除能力,采用不同浓度的碱处理和不同温度的氮修饰对ACF进行耦合改性,对共同改性后的ACF进行SEM、BET和XPS等分析测试,获得相关物理化学参数,并评价其吸附去除甲醛气体的性能。研究结果表明：碱处理后的ACF获得了发达的微孔结构和较高的比表面积。氮修饰后,ACF表面含氮官能团数量明显提高。改性后的ACF去除甲醛的性能得到了明显的提升,对初始浓度为4 mg·m-3的甲醛去除率高达98%。吸附去除甲醛性能的提高应该归因于比表面积的大幅度提升和表面含氮官能团数量增加的共同作用。     

高强紫外球形灯光解氧化硫化氢气体

提出了采用可产臭氧的高强球形紫外灯光解氧化硫化氢气体。考察了硫化氢初始浓度、湿度、含氧量、停留时间对硫化氢去除效率的影响。实验结果表明,硫化氢浓度在低浓度范围内,对硫化氢的去除效率可以达到99％以上。反应体系内气体湿度比含氧量对硫化氢的去除效率的影响更明显。气体湿度控制在45％～60％和反应停留时间控制在6～10s范围内为最佳。高强紫外球形灯处理硫化氢过程分别存在直接光解和臭氧氧化作用及两者的协同作用。     

不同预处理方法对活性炭纤维结构和吸附性能的影响

以商品活性炭纤维为原材料,采用水洗和HNO3、H3PO4和HF酸洗方法对其进行预处理。利用扫描电镜、比表面积测定仪及傅立叶红外光谱仪对其表面形貌和结构进行表征,并通过测定灰分含量、碘值和苯酚值考察其吸附性能。结果表明:预处理后活性炭纤维的形状和尺寸变得相对规整,表面酸性官能团数量增加,吸收谱峰变得尖锐,比表面积和总孔容增大。HF水浴去灰分效果最佳可达84.8%;H3PO4活化炭化的碘和苯酚吸附值最高,分别为1 925 mg/g和226 mg/g;而HNO3活化会造成表面刻蚀,碘和苯酚吸附值最低。确定H3PO4活化炭化为本实验最佳预处理方法。     

Surface chemistry of activated carbons and its relevance for effects of relative humidity on adsorption of chlorinated organic vapors

The effects of relative humidity (RH) on the adsorption of methylene chloride (METH) and 1,1,1-trichloroethane (TCEA) on two commercial activated carbons, made from bituminous coal (carbon BPL) and coconut shell (carbon PCB), were studied. Three levels of RH were tested by tracking the breakthrough curves of each adsorbate eluted from a fixed-bed adsorption column. Adsorption capacities for these adsorbates were decreased with increase of RH. The magnitude of the effect of water vapor on adsorption is greater for carbon BPL and METH than for carbon PCB and TCEA. The results of the effect of water vapor on the adsorption capacity observed in this study were further examined based on the chemical characterization of activated carbons and the fundamental physical differences between the adsorbates.     

硫化氢的强化分离及其对产酸脱硫生物反应系统的影响

在完全混合式产酸脱硫生物系统中,利用负压抽提法强化H2S的气液分离,以NaOH溶液吸收H2S气体。抽提装置实现对H2S自动、连续抽提与吸收,在60mmH2O柱负压力范围分离出H2S的量与抽提压力呈线性正相关。抽提作用可促进SRB对碳源底物的转化,显著提高硫化物的气/液比例,增加系统中硫化物的转化率。抽提后硫化物的气/液比例(摩尔比)由0044上升到061、分离出的H2S在硫化物总生成量中的比例由42%增加到356%,硫化物转化率由平均494%提高至610%。抽提作用可以提高系统的硫酸盐去除率和酸碱缓冲能力,同时可以纯化和浓缩H2S。     

Oxidation of gas mixtures containing dimethyl sulfide, hydrogen sulfide, and methanethiol using a two-stage biotrickling filter

A biofiltration technique was developed for removing a mixture of hydrogen sulfide (H2S), methanethiol (MeSH), and dimethyl sulfide (Me2S) from waste gases. Since H2S, especially at high concentrations, disturbs the removal of Me2S, two biotrickling filters with different microbes and operating pH levels were connected in series to create a two-stage system. Different loads of these gases were studied in order to determine their impact on the removal capacity of the system. The microbial consortia for these filters were enriched from the sludge of a Finnish refinery with bubbling H2S or Me2S. Acclimation for Me2S took 2 weeks, though no acclimation time was needed for the other gases. The first filter, at a pH of 2, removed most of the H2S and some of the MeSH and Me2S. The second filter, at a pH of approximately 6.5, removed the rest of the MeSH and most of the Me2S. The total maximum loads of the whole two-stage biotrickling filter were 1150 g/m3/day for H2S-S (suffix S indicates the results are counted as sulfur amounts), 879 g/m3/day for Me2S-S, and 66 g/m3/day for MeSH-S treated in a gas mixture. The average removal efficiencies for all gases tested were 99% or higher.