有机胺溶液吸收SO2的研究

提出了常压下在鼓泡式反应器中以三种不同的有机胺(乙二胺、二乙烯三胺及三乙烯四胺)溶液作为吸收剂进行吸收及解吸SO2的新工艺。探讨了二乙烯三胺—胺—水多元体系在吸收SO2过程中的特性,考察了溶液初始pH、吸收剂浓度、有机胺配比等因素对SO2吸收量的影响规律,确定了实验室规模下适宜的最佳吸收条件:温度30~40℃,初始pH6~7,吸收液浓度(有机胺/水)为5/200~8/200(体积比),二乙烯三胺/三乙烯四胺体积比为4/1。     

TETA溶液脱除模拟烟气中CO_2的试验研究

CO_2作为全球温室气体,正在危害人类赖以生存的环境,而工业上现正在大力发展有机胺溶液用于脱除烟气中的CO_2,并已得到了广泛的应用和极好的发展趋势.由于三乙烯四胺(TETA)溶液具有稳定性好、吸收效率高等优势,再对比传统胺试剂试验的浓度,试验选取0.2~0.8mol/L体积浓度范围的TETA作为吸收剂吸收模拟烟气中的CO_2.当温度在25~40℃时,其温度对CO_2吸收速率的影响不明显;当溶剂体积浓度在0.2~0.8mol/L和CO_2体积分数在10%~18%时,溶剂体积浓度和CO_2体积分数对CO_2吸收速率的影响明显.     

用混合醇胺吸收燃煤烟气中CO_2的试验研究

研究了用乙醇胺(MEA)和三乙醇胺(TEA)混合物从燃煤烟气中吸收CO2,通过控制变量法获得适宜的工艺参数:反应温度20℃,溶剂组成0.6mol/L(MEA)+0.4mol/L(TEA),CO2体积分数12%,模拟烟气流量500L/h。适宜条件下,混合醇胺的吸收速率为5.67×10-4 mol/s,比纯MEA的吸收速率4.63×10-4 mol/s更快。     

化学法吸收燃煤烟气中CO_2的研究

以乙醇胺(MEA)和四乙烯五胺(TEPA)作为吸收剂吸收燃煤烟气中的CO2。在反应温度20℃、溶剂体积浓度5%、CO2体积浓度13%、模拟烟气流量550L/h时,MEA和TEPA的吸收速率分别为0.659和0.513mmol/s。     

冷却速率对无取向硅钢中夹杂物析出行为的影响

借助高温激光共聚焦显微镜实时观察了无取向硅钢(/%:0.001 8C,0.76Si,0.24Mn,0.074P,0.003S,0.001 Al,0.005 60,0.001 1N)连铸坯切取的试样从1 400℃以5~40℃/s的速率冷却至600℃时组织变化,并在实时观察后用非水溶液电解提取和分析了试样中的夹杂物。结果表明,冷却至987~1 020℃(高温)和830~636℃(低温)两阶段,分别开始有新相析出,并分别于952~918℃和804~636℃析出结束。第一(高温)阶段,随冷却速率增加,新相的开始、结束析出温度均升高,但析出温度区间减小;第二(低温)阶段,随冷却速率增加新相的开始、结束析出温度均降低,但析出温度区间增大;此外在较低冷却速率下,高温阶段有利于新相充分析出,在较高冷却速率下,低温阶段有利于新相充分析出;随着冷却速率增加,夹杂物抑制晶粒长大的效果逐渐减少,试样平均晶粒尺寸先是减少,并在10℃/s时达到最小,而后单调、快速增加。因此,应该选择5℃/s以下或者20℃/s以上的冷却速率,并尽可能避免生成0.21~0.50μm MnS、AlN以及冷却后期析出的Cu_xS夹杂物,使成品获得较好的磁性能。      

氮气压力对锰球氮化反应的影响(Ⅰ)

利用自制的密闭氮化系统研究了不同压力下的锰球氮化反应。锰球的制备条件为:锰粉重量100 g、锰粉粒度16~20目、粘结剂添加量质量分数为2%和成球压力354 MPa。氮化炉温为900℃,氮化时间3 600 s。实验记录了在不同的氮气压力下锰球氮化实时增重和温度曲线。实验结果显示,当氮气压力从0.2 MPa升高至0.6 MPa时:(1)反应速率峰值时刻由266 s缩短至86 s,球心温度峰值时间由324 s缩短至138 s,球心温度恢复至炉温时由1 310 s缩短至642 s;(2)球心温度峰值由945℃升高至1 049℃,球心最大温升由55℃升高至159℃;(3)氮化3 600 s时的增重率由6.46%增至8.09%,转化率由81.34%增至93.62%;(4)增重速率峰值由8.15×10~(-3)s~(-1)增至62.7×10~(-3)s~(-1),转化速率峰值由103×10~(-3)s~(-1)增至726×10~(-3)s~(-1);(5)增重率达到6.46%的时间由3 600 s缩短为555 s,缩短84.6%。     

460MPa级海洋平台用钢的高温塑性研究

通过Gleeble-1500D热模拟机来进行EQ47(460 MPa)钢的高温塑性研究,以1×10-3/s的变形速率,在600~1 350℃的温度区间内以每50℃取一间隔做一组高温塑性试验.结果表明:在907~1 270℃之间,断面收缩率均高于60%,钢的高温塑性良好,温度高于1 270℃时,断面收缩率急剧下降,第Ⅲ脆性区在667~907℃之间,在此温度区间内存在明显的塑性低谷,断面收缩率最低值为29.44%.     

酸洗后201×7树脂上金属铜的解吸研究

针对硫酸溶液可以有效洗脱树脂上的氰化物和锌,但不能洗脱铜的工艺问题,选择氨水溶液对酸洗后201×7树脂上的铜进行解吸;试验研究了解吸过程的时间、温度以及超声波作用等条件对解吸率的影响,并进行了X射线荧光分析。试验结果表明,在25℃时,8%的氨水溶液可以有效解吸酸洗后201×7树脂上负载的铜,解吸率可以达到85%,解吸速率常数k=4.93×10-4/s,解吸过程的表观活化能为12.058kJ/mol。     

加热速率对镀锌热成形钢镀层组织的影响

利用扫描电镜(SEM)及附带能谱仪系统(EDS)和辉光放电光学光谱仪(GDOES),研究了不同的加热速率对镀锌热成形钢镀层组织的影响。结果表明,镀层组织主要由Γ相和α-Fe(Zn)组成,随着加热速率的降低,锌镀层中的α-Fe(Zn)相增多,Γ相比例减少。当加热速率为5~15℃/s时,镀层中主要以α-Fe(Zn)为主,Γ相很少,且靠近铁基体侧无Γ相;随着加热速率的降低,镀层中铁质量分数逐渐增多,合金化镀层厚度逐渐增厚;加热速率为15℃/s,镀层中的铁和锌分布地较均匀;加热温度为900℃时,控制加热速率为5~15℃/s,可有效减少或避免液态金属致脆性(LMIE)裂纹的产生。     

201×7树脂负载Fe(CN)3-6的解吸

文中对201×7强碱性离子交换树脂负载的铁氰化物进行了解吸研究,以解决酸洗脱树脂过程中出现的问题。采用水合肼和氯化钠混合溶液可有效解吸树脂上负载的铁氰化物;在室温条件下,解吸溶液为2%水合肼 100g/L氯化钠时,三价铁解吸率可以达到98%以上。在试验条件下,测得解吸速率常数k=8.88×10-4/s,60m in基本达到解吸平衡。随着温度的升高,解吸速率逐渐增大,表明解吸过程是一个吸热过程,升温有利于解吸进行,但解吸过程的表观活化能为0.625kJ/mol,表明反应速率对温度不是很敏感,解吸过程可以在室温下进行。     

Ozonation of Propranolol: Transformation, Biodegradability, and Toxicity Assessment

This work studies the ozonation of the pharmaceutical propranolol (PRO) in aqueous solution. Experimental results demonstrated that ozonation was an efficient method to remove PRO, achieving its complete abatement after 8?min of treatment (ozone dose of 0.47??mmol?L-1), starting from a PRO initial concentration of 0.38??mmol?L-1. The total organic carbon (TOC) analysis indicated that 1?h of ozonation (ozone dose of 3.54??mmol?L-1) was able to achieve only about 5% of the total organic carbon removal. The ozonation of PRO aqueous solutions has not promoted a prompt increase of the ratio of biological oxygen demand to chemical oxygen demand, thus indicating the need for higher ozone doses to initiate the biodegradability enhancement. The acute toxicity increased in the first minutes of reaction with a posterior reduction to values slightly higher than the toxicity of the PRO raw solution. Some early intermediate structures were proposed, and finally, kinetic constants for the direct attack of ozone on PRO structure were calculated. These values are in the order of magnitude of 105??L?mol-1?s-1.     

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The ductile- brittle transition temperature and its influencing factors of Cr- Co- Mo- Ni bearing steel after solid solution heat treatments at different temperatures were investigated through analysis on ductile- brittle transition temperature and the trend of ductile- brittle transition of impact fracture. Results show that the ductile- brittle transition temperatures of the samples after solid solutions at 1000, 1030 and 1060?? are above 100??. After solid solution at 1090??, the ductile- brittle transition temperature is 70?? and the impact energy is above 47J at -50??. After solid solution at 1120??, the ductile- brittle transition temperature is 52?? and the impact energy is above 46J at -50??. Ductile- brittle transition temperature reduces and original grain size increases with the increasing of solid solution temperature because of big precipitations of M6C at grain boundary.     

Effect of magnesium addition on microstructure and mechanical properties in wheel steel

In order to reveal the effect of Mg in low carbon microalloy steel, low carbon microalloy steel of HR60 wheel steel was smelted in vacuum induction furnace and industrial field respectively. The characteristics of typical non- metallic inclusions and microstructure of experimental steels were both compared by OM, SEM- EDS and INCA Feature with automatically scanning inclusions function. The mechanical properties of the experimental steels were also measured. The results show that alumina inclusions are modified to spinel inclusions with small size after Mg addition. Furthermore, acicular ferrite can be induced effectively by inclusions containing magnesium. The microstructures of experimental steels are changed from ??polygonal ferrite(PF) + pearlite(P)??to ??polygonal ferrite(PF) + degenerate pearlite(DP) + acicular ferrite(AF)?? and refined by Mg treatment. The strength of experimental steels is improved with Mg addition. In industrial experiments, the fatigue limit of Mg- treated steels is greater than 460MPa, while the fatigue limit of Ca- treated steels is about 450MPa. In addition, the fatigue life of Mg- treated steels is generally higher than that of Ca- treated steels under the condition that the stress is greater than the fatigue limit. In laboratory experiments, the contents of Nb and Ti are reduced while Mg content in steel is 18??10-6, the strength of the wheel steel is close to the reference steel. Therefore, the project to reducing production cost by taking advantage of the microalloy role of Mg is feasible.     

树脂法提取茶多酚的工艺研究

利用12种树脂对茶汤中茶多酚的吸附和脱附性能进行研究，得出DM-16X大孔吸附树脂是较优实验树脂.实验重点研究了DM-16X树脂对茶多酚的动态吸附与脱附工艺.结果得出当吸附速度为6 BV/h（1 BV=10 mL树脂体积）时，茶多酚的吸附效果较优；在吸附流速为6 BV/h时，为避免发生穿透现象，含茶多酚浓度为1.51 mg/mL的茶汤在吸附实验中体积控制在12.5 BV以内.在脱附实验中，脱附液为含乙醇70%的溶液，在脱附液体积为80 mL和脱附液流速为8 BV/h时，脱附效果较好.在较优操作工艺条件下，制得的茶多酚纯度可达到76.57%，其中4种儿茶素EGC、EC、ECG、EGCG的总含量达到了65.62%，咖啡碱含量为16.96%.      

快速测定有机胺中氯离子含量

实验以硫氰酸汞乙醇溶液为显色液,采用分光光度法于460 nm波长处测定有机胺中氯离子含量。通过实验对显色剂用量、显色时间、加酸量等条件进行了优化,并进行了干扰离子消除试验。本方法的检出限为0.0342μg/mL,方法回收率93.10%~104.60%,RSD≤1.75%,检测快速、准确、灵敏度高、精密度好,适用于有机胺中氯离子含量的测定。     

Response of Soil Water Chemistry to Simulated Changes in Acid Deposition in the Great Smoky Mountains

Watershed recovery from acidic deposition, such as the Noland Divide Watershed in the Great Smoky Mountains National Park, is difficult to predict because of complex biogeochemical processes exhibited in soils. Laboratory soil columns and in?situ pan lysimeters were used to investigate soil solution response to simulated reductions in acid deposition. Controlling for influent SO42-, NO3-, and NH4+ concentrations in the column experiments, effluent pH declined similarly to 4.4 among five experimental scenarios from an initial pH of approximately 4.7 and 6.1. Influent-effluent chemical comparisons suggest nitrification and/or SO42- desorption controls effluent pH. Sulfate adsorption occurred when SO42- influent was greater than 25??μmol?L-1 and desorption occurred below 15??μmol?L-1, which would equate to approximately a 61% reduction in current SO42- deposition levels. Base cation depletion occurred in column experiments, in which 64–60??μmol?L-1 Ca2+ and 24–27??μmol?L-1 Mg2+ reductions were measured. Cation depletion rates were pH dependent, primarily caused by soil cation exchange and not weathering. In these soils with base saturation below 7%, complete Ca2+ and Mg2+ depletion was estimated as 90 to 140?years. Protons released by SO42- desorption via ligand exchange are expected to cause further base cation depletion, thereby delaying watershed recovery. Field experiments found SO42- sorption dynamics to be limited by kinetics and hydrologic interflow rates, illustrating how precipitation intensity can influence ion transport from soil to stream. Results from this study provide important information for predicting watershed recovery in the future and suggest needs for further research.     

铬天青S光度法测定赤泥-钛白废水综合回收中的微量钪

采用铬天青S作显色剂,研究了在赤泥-钛白废水综合回收过程中微量钪的分光光度法测定。考察了反应条件、共存离子等因素对检测结果的影响,确定了硫酸浸出液中钪的最佳检测条件为采用伯胺N₁₉₂₃为萃取剂,HCl为反萃剂,相比为1.0,萃取时间为10 min,显色剂铬天青S(CAS)的体积为4.00 mL,显色溶液的pH值为1.0~1.5,显色时间为30 min。加入1.00 mL盐酸羟胺溶液、2.00 mL邻菲罗啉溶液作为掩蔽剂可消除残留于溶液中少量Fe的干扰。试验结果表明,络合物的最大吸收波长为615 nm,表观摩尔吸光系数为2.85×10⁵L·mol^-1·cm^-1,钪的质量浓度在0 ~ 0.18 mg/L范围内符合比尔定律,校准曲线的相关系数为0.999 1。对钛白废水实际样品进行分析,实验方法与ICP-AES法测钪的相对误差在5%之内,钪测定结果的相对标准偏差(RSD,n>6)为2.4%~4.1%。     

矿山含铜氰废水资源化利用工艺研究

采用"活性炭吸附—解吸联合工艺"处理某矿山的含铜氰废水。吸附阶段考察了吸附液pH和吸附方式对含铜氰废水中铜吸附率的影响,解吸阶段考察了解吸方式、时间、解吸液的硫酸和双氧水浓度对含铜炭中铜解吸率的影响。结果表明,先将含铜氰废水pH调至8左右,然后在5级串联吸附条件下吸附1.5h,铜的吸附率均稳定在90%以上,吨炭铜含量为31.4kg;所得含铜炭采用淋滤解吸,并在解吸液的双氧水和硫酸浓度分别为2g/L和3%条件下解吸7h,铜解吸率为87.60%,整个工艺铜的直收率达78%以上。     

Migration of Heavy Metals in Saturated Sand and Bentonite/Soil Admixture

Heavy metal migration through compacted, saturated sand and bentonite/soil admixtures were investigated using kinetic, batch sorption tests, and column tests. Sorption of Pb, Zn, and Cd at pH 5 by bentonite is found to be 411.2, 163.4, and 71.8 mL/g, respectively. The permeability of the compacted sand (8×10?4?cm/s) is found to be 6 orders of magniture higher than that of bentonite/soil admixture (about 8×10?10?cm/s) when permeated with metal solutions under an effective stress of 34.5 kPa (5 psi). The permeation of metal solutions into bentonite/soil admixture columns does not result in a significant increase in permeability. Experimental results of batch sorption and hydraulic conductivity tests were also analyzed with a computer-based simulation model, POLLUTE, to determine the transport parameters (effective porosity, dispersion coefficient, retardation) of chloride ions and heavy metals in a homogeneous compacted sand and bentonite/soil admixture using a curve fitting technique.