吸附法净化低浓度废气实验研究

本文探讨了用活性炭吸附低浓度苯类废气进，空塔气速和气流在吸附层的接触时间对吸附过程的影响，研究了活性炭在已经吸附若干质量的苯类物质以后的吸附。据此绘制了空塔气速一吸附效率和活性炭含苯率一吸附效率等关系曲线，工进行了活性炭再生的研究。研究表明，使用活性炭可以有效地净化低浓度苯类废气。     

吸附法净化低浓度废气实验研究

本文探讨了用活性炭吸附低浓度苯类废气时,空塔气速和气流在吸附层的接触时间对吸附过程的影响;研究了活性炭在已经吸附若干质量的苯类物质以后的吸附性能.据此绘制了空塔气建-吸附效率和活性炭含苯率-吸附效率等关系曲线,并进行了活性炭再生的研究.研究表明:使用活性炭可以有效地净化低浓度苯类废气.     

活性炭处理甲苯气体吸附再生实验研究

研究了活性炭对甲苯废气的吸附穿透过程及热空气解吸过程.穿透曲线实验结果表明,在常规空塔气速范围内,传质区高度基本在5.06～9.75 cm,传质区不饱和度在0.4～0.7.在动态运行情况下,活性炭对甲苯的饱和吸附容量在0.16～0.24 g/g.热空气吹脱实验表明,适宜的脱附工况条件为脱附温度180 ℃、脱附空气流速0.106 m/s、脱附时间40 min.     

烧结纤维承载活性炭复合材料在苯蒸气脱除中的应用

以8μm的镍纤维和煤基活性炭为原材料,通过抄制和烧结工艺制备了烧结纤维承载活性炭粉末复合材料。为了减轻床层总重量,将这种材料和通常的颗粒状活性炭进行联合装填形成复合层,并进行了苯蒸气的吸附穿透实验。利用Wheeler方程对床层的饱和吸附容量和吸附速率常数进行了测定。结果表明,在相同的测试条件下,联合装填层比单独的颗粒炭装填层具有更好的苯蒸气脱除性能;对两种床层而言,其各自的饱和吸附容量是一个不随比速而变化的常数,而随着气流比速的增加,两种床层的吸附速度都呈增加的趋势。     

颗粒活性炭去除水中甲基叔丁基醚的可行性研究

随着甲基叔丁基醚（MTBE）作为汽油添加剂被持续大量使用，其已成为一种地下水中常见的有机污染物。本文通过纯净水、自来水和地下水中MTBE的平衡吸附容量和微型快速穿透实验（MCRB），比较了5种不同种类活性炭对MTBE的吸附性能。结果显示，苯酚值可准确预测活性炭样品对MTBE的平衡吸附容量大小次序，而丹宁酸值则可大致估计活性炭在实际处理应用时的吸附速度和吸附容量利用率。水样中共存的有机成分降低了活性炭对纯净水中MTBE的吸附容量，在背景TOC较低的去离子水中，活性炭对于MTBE的吸附性能反而比在地下水中降低得更多。穿透实验数据显示双柱串联的处理方式是高效应用活性炭吸附水中MTBE的优选工艺。使用环境友好的竹质活性炭去除地下水中MTBE具有良好的可行性和较高的性价比。     

颗粒活性炭吸附去除水中三氯乙烯的研究

通过吸附容量实验及微型快速穿透(MCRB)实验,考察了7种活性炭对水样中三氯乙烯(TCE)的去除效果.结果表明,表征活性炭对小分子化合物吸附容量的苯酚值可以预测各种活性炭对TCE的吸附容量;国内常用炭型对TCE的吸附性能与国际常用炭型相当.性价比更高;不同TCE初始浓度及低浓度甲醇对TCE吸附容量没有明显的影响,而自来水中天然有机物(NOM)的竞争吸附作用会降低活性炭对TCE的吸附容量;MCRB实验数据提供了较为准确的TCE平衡吸附容量.验证了各种活性炭对TCE的相对吸附容量,并显示使用2个串联活性炭炭床可以提高吸附容量利用率,节省处理费用,确保出水达标.     

脱灰煤基活性炭吸附处理含镉废水简

考察了硝酸脱灰煤样自制活性炭对Cd（Ⅱ）的吸附去除特征。结果表明，随煤样粒径的减小，活性炭的吸附能力增强，吸附过程符合分形动力学特征；随着镉浓度的升高，活性炭对镉的吸附量增加，活性炭吸附镉符合Langmuir 等温方程，镉离子在活性炭上的吸附属单分子层吸附；煤基活性炭适宜的吸附除镉条件为粒径0.054 mm、Cd（Ⅱ）初始浓度35 mg/L、活性炭用量0.05 g、吸附时间1 h，此时的吸附容量达40 mg/g。     

脱灰煤基活性炭吸附处理含镉废水

考察了硝酸脱灰煤样自制活性炭对Cd（Ⅱ）的吸附去除特征。结果表明，随煤样粒径的减小，活性炭的吸附能力增强，吸附过程符合分形动力学特征；随着镉浓度的升高，活性炭对镉的吸附量增加，活性炭吸附镉符合Langmuir等温方程，镉离子在活性炭上的吸附属单分子层吸附；煤基活性炭适宜的吸附除镉条件为粒径0．054mm、Cd（Ⅱ）初始浓度35mg／L、活性炭用量0．05g、吸附时间1h，此时的吸附容量达40mg／g。     

污泥活性炭固定床吸附甲苯

采用ZnCl2化学活化法制备的污泥活性炭用于固定床吸附甲苯实验,研究了吸附剂床层厚度、甲苯初始浓度、气体线速等操作条件对其吸附性能的影响,并建立了污泥活性炭吸附甲苯的传质模型,计算不同操作条件下的传质区长度和物质总传质系数。结果表明,当床层厚度从3 cm增加到7 cm,传质区长度基本不变,物质总传质系数增加了66.66%;当甲苯初始浓度增大3.36倍,传质区长度增加了17.19%,而物质总传质系数降低了22.05%;在实验流速范围内,气体线速变为原来的2倍,物质总传质系数增加了65.27%,说明污泥活性炭对甲苯吸附属于外扩散控制。     

改性污泥活性炭对水中镉离子的吸附性能

以城市污水处理厂的剩余污泥为原料,氯化锌为活化剂制备污泥活性炭,对一部分污泥活性炭用6.0 mol/L的硝酸进行改性,并研究了未改性和改性的污泥活性炭对Cd2＋的吸附行为的影响。结果表明,在pH为5.0、Cd2＋初始浓度为100 mg/L、吸附剂投加量为2.0 g/L、反应温度为25℃时,未改性的污泥活性炭吸附容量为8.45 mg/g,硝酸改性的污泥活性炭吸附容量达到了23.35 mg/g。改性和未改性的污泥活性炭对Cd2＋都有较好的吸附容量,硝酸改性大幅度提高了污泥活性炭对Cd2＋的吸附性能。常温下改性污泥活性炭对Cd2＋的吸附符合Langmuir吸附等温式。     

新生MnO2对水中酸性媒介深黄GG的吸附脱色作用

以化学法合成的新生MnO2作吸附，对水中酸性媒介深黄GG进行吸附脱色研究，探讨了影响吸附的因素，结果表明，该吸附剂在PH1．5以下，投加量为0.3mg/L，温度为15℃条件下，饱和吸附量达1320mg/g，脱色率达96％以上，具有很高的吸附脱色能力。PH值是能力吸附能力的关键因素，温度，染料浓度和MnO2投加量影响程度较小。     

The adsorptive capacity of vapor-phase mercury chloride onto powdered activated carbon derived from waste tires

Injection of powdered activated carbon (PAC) upstream of particulate removal devices (such as electrostatic precipitator and baghouses) has been used effectively to remove hazardous air pollutants, particularly mercury-containing pollutants, emitted from combustors and incinerators. Compared with commercial PACs (CPACs), an alternative PAC derived from waste tires (WPAC) was prepared for this study. The equilibrium adsorptive capacity of mercury chloride (HgCl2) vapor onto the WPAC was further evaluated with a self-designed bench-scale adsorption column system. The adsorption temperatures investigated in the adsorption column were controlled at 25 and 150 degrees C. The superficial velocity and residence time of the flow were 0.01 m/sec and 4 sec, respectively. The adsorption column tests were run under nitrogen gas flow. Experimental results showed that WPAC with higher Brunauer-Emmett-Teller (BET) surface area could adsorb more HgCl2 at room temperature. The equilibrium adsorptive capacity of HgCl2 for WPAC measured in this study was 1.49 x 10(-1) mg HgCl2/g PAC at 25 degrees C with an initial HgCI2 concentration of 25 microg/m3. With the increase of adsorption temperature < or = 150 degrees C, the equilibrium adsorptive capacity of HgCl2 for WPAC was decreased to 1.34 x 10(-1) mg HgCl2/g PAC. Furthermore, WPAC with higher sulfur contents could adsorb even more HgCl2 because of the reactions between sulfur and Hg2+ at 150 degrees C. It was demonstrated that the mechanisms for adsorbing HgCl2 onto WPAC were physical adsorption and chemisorption at 25 and 150 degrees C, respectively. Experimental results also indicated that the apparent overall driving force model appeared to have the good correlation with correlation coefficients (r) > 0.998 for HgCl2 adsorption at 25 and 150 degrees C. Moreover, the equilibrium adsorptive capacity of HgCl2 for virgin WPAC was similar to that for CPAC at 25 degrees C, whereas it was slightly higher for sulfurized WPAC than for CPAC at 150 degrees C.     

超声波及其联用技术降解废水中的氯苯

研究了在降解含氯苯废水的过程中，超声波分别与H2O2、O2、空气联用对氯苯降解效率的影响。结果表明，超声波分别与H2O2、O2、空气联用比单独使用超声波降解效率分别提高40、30、18个百分点。并且随H2O2用量的增加，降解效率明显升高。对于O2、空气，当气体流量小于0．3754mL／s时，降解效率随O2、空气流量的增大而明显升高。     

分散填料曝气塔多相流态分析与传氧性能表征

针对分散填料曝气塔中多相流的流态与传氧过程,实验了布气方式以及海绵和陶粒2种填料对于体系的气含率εg、流态以及气-液传质性能的影响。在表观气速U范围(0.01～0.18 m/s)内观察到81孔布气板(Φ1 mm)体系出现3个明显相区,孔数过少(25孔),或者孔间距较小(225孔)均没有明显过渡区,在湍流区(U>0.118 m/s)3种布气板的气含率没有明显差别。海绵填料体积分数εs<25%时体系的气含率没有明显变化,35%时气含率下降且过渡区提前出现。在非均相区,海绵填料明显提高了体系的传质系数KLa。陶粒填料降低了气含率,固含率对εg的影响差别不明显,同时降低了多相流体系的KLa,且随着固含率的增加KLa降低。对比多种操作条件,单位体积空气传氧能力KLa/εg无明显差别,但在81孔布气板的过渡区KLa/εg出现一个明显的极小区间,说明过渡区传氧效率较低。在特定的实验操作条件下,KLa/εg较为稳定,这为深入理解两种气泡群体的共存体系在传氧性能方面各自的权重,提供了重要的量化参考。     

旋风静电除尘器流场分布测试研究

利用五孔探针系统对直筒式旋风静电除尘器模型的三维流场进行了测定与分析.结果表明:随着入口风速、供电电压增加,旋风静电除尘器内气流的切向和径向速度分别增加,各截面轴向速度沿半径的分布基本相似;与旋风除尘器相比,旋风静电除尘器内气流的切向速度和径向速度的变化更为平缓,入口风速为8.5 m/s时,在0.3～0.5倍简体直径时,切向速度达最大.     

自由旋片除雾器脱水性能实验研究

提出一种新型除雾装置——自由旋片除雾器。在实验室条件下,从除雾效率、压力损失两方面研究了自由旋片除雾器的性能。实验结果表明,风速在11 m/s左右时,自由旋片除雾器的除雾效率达到最大值。对比实验发现,自由旋片除雾器的除雾效率远高于固定叶片除雾器的除雾效率,二者的除雾效率最大值相差约10%。自由旋片除雾器的除雾效率变化曲线在6~13 m/s的流速范围内相当平滑,说明自由旋片除雾器对含雾气流流速的波动有很好的适应性。另外,增加液气比和雾滴粒径会提高自由旋片除雾器的除雾效率。自由旋片除雾器压力损失系数仅为4.3,而固定叶片除雾器压力损失系数为6.6。所以,自由旋片除雾器的阻力特性远优于固定叶片除雾器。     

The Adsorptive Capacity of Vapor-Phase Mercury Chloride onto Powdered Activated Carbon Derived from Waste Tires

Abstract

Injection of powdered activated carbon (PAC) upstream of particulate removal devices (such as electrostatic precipitator and baghouses) has been used effectively to remove hazardous air pollutants, particularly mercury-containing pollutants, emitted from combustors and incinerators. Compared with commercial PACs (CPACs), an alternative PAC derived from waste tires (WPAC) was prepared for this study. The equilibrium adsorptive capacity of mercury chloride (HgCl₂) vapor onto the WPAC was further evaluated with a self-designed bench-scale adsorption column system. The adsorption temperatures investigated in the adsorption column were controlled at 25 and 150 °C. The superficial velocity and residence time of the flow were 0.01 m/sec and 4 sec, respectively. The adsorption column tests were run under nitrogen gas flow. Experimental results showed that WPAC with higher Brunauer–Emmett–Teller (BET) surface area could adsorb more HgCl₂ at room temperature. The equilibrium adsorptive capacity of HgCl₂ for WPAC measured in this study was 1.49 × 10^?1 mg HgCl₂/g PAC at 25 °C with an initial HgCl₂ concentration of 25 μg/m³. With the increase of adsorption temperature ≤150 °C, the equilibrium adsorptive capacity of HgCl₂ for WPAC was decreased to 1.×34 10^?1 mg HgCl₂/g PA≤C. Furthermore,WPAC with higher sulfur contents could adsorb even more HgCl₂ because of the reactions between sulfur and Hg²⁺ at 150 °C. It was demonstrated that the mechanisms for adsorbing HgCl₂ onto WPAC were physical adsorption and chemisorption at 25 and 150 °C, respectively. Experimental results also indicated that the apparent overall driving force model appeared to have the good correlation with correlation coefficients (r) >0.998 for HgCl₂ adsorption at 25 and 150 °C. Moreover, the equilibrium adsorptive capacity of HgCl₂ for virgin WPAC was similar to that for CPAC at 25 °C, whereas it was slightly higher for sulfurized WPAC than for CPAC at 150 °C.     

Gas phase transport in gravity sewers--A methodology for determination of horizontal gas transport and ventilation.

A method was developed for determination of horizontal gas transport and ventilation in gravity sewers. This was achieved by changing the composition of the sewer atmosphere by pulse injection of oxygen gas and subsequently measuring the oxygen concentration in a downstream manhole. Conventional tracer techniques may require sampling and may also affect the environment. The method developed is simple, based on direct monitoring and without environmental or toxic effects. The method was developed based on measurements in an intercepting gravity sewer. The horizontal gas transport processes were quantified by measuring the velocity and dispersion of the gas in the sewer atmosphere. Based on 54 measurements, the gas velocity was found to vary between 0.05 and 0.22 m/s. The coefficients of dispersion were calculated to be in the range 0.05 to 1.1 m2/s. Climatic conditions did not significantly influence the gas phase transport.     

水吸收法处理低浓度氮氧化物废气的中试研究

对水在中试规模下吸收低浓度的氮氧化物废气进行了研究。分别研究了喷淋密度、温度、压力、气速以及氮氧化物浓度对吸收效果的影响,结果表明,综合考虑各种因素,喷淋密度在20 m3/（m2·h）,水温在15℃以下,气速小于0.28 m/s,废气浓度在400 mg/m3左右时,氮氧化物的平均脱除率可以达到50%左右;同时,随着压力的增大,吸收效率也增加。     

尿素/三乙醇胺吸收烟气NO_x的实验研究

以尿素作为吸收液,与NOx反应生成N2和CO2,脱除烟气中的氮氧化物。以一套双级串连的填料塔为主体反应器,分别对气速、液气比、反应物浓度、添加剂浓度和反应温度等参数对尿素溶液吸收NOx反应的影响进行了实验研究,获得了优化实验工况,研究结果显示,在气速为0.1 m/s、液气比为16 L/m3、三乙醇胺为0.01%（质量比）、尿素浓度为13%（质量比）工况下,反应温度为30~70℃,脱硝总效率可达50%以上,且随着NOx体积分数增加而提高。