气相中乙酸乙酯光解的光子效率:波长和催化剂的影响

采用4种不同波长的准分子光源(Xe Cl*、Kr Cl*、Xe Br*和Kr Br*)降解气相的乙酸乙酯.对比了外加3种负载型光催化剂(有机膜负载Ti O2、有机膜负载石墨烯和纱网负载Ti O2)条件下乙酸乙酯的去除率,考察了光源类型、辐射功率和气体初始浓度对去除率的影响.同时,测定了不同光源的辐射光谱和辐射功率,计算了不同反应条件下的光子效率.结果表明,乙酸乙酯去除率按Kr Br*Kr Cl*Xe Cl*Xe Br*依次降低,而Xe Cl*和Kr Br*光源降解乙酸乙酯气体可以得到较高的光子效率;有机膜负载Ti O2比不加催化剂时乙酸乙酯去除率和光子效率都有所提高,但提高幅度不大.气体流速和乙酸乙酯初始浓度升高,光子效率升高.采用Kr Br*准分子灯直接光解乙酸乙酯,实验条件为:辐射功率0.76 W,乙酸乙酯初始浓度946mg·m-3,气体流速600 m L·min-1,光子效率为5.63%.     

醋酸钙溶液吸收二氧化硫烟气的试验研究

介绍了醋酸钙溶液吸收二氧化硫烟气的小型试验和扩大试验,试验结果表明,醋酸钙溶液对二氧化硫有较强的吸收能力和较快的吸收速度,通过二级吸收后,烟气中二氧化硫的浓度能够低于0.05%的国家排放标准要求。     

双室微生物燃料电池利用乙酸钠和淀粉产电研究

研究了厌氧活性污泥接种的双室微生物燃料电池(Microbial Fuel Cells,MFCs) 分别供给以乙酸钠和淀粉为底物的人工配水的产电情况和有机物去除效果. 结果表明,MFCs中能量的输出与底物的种类有关,使用乙酸钠和淀粉达到的最大输出电压分别为0.43和0.39 V,最大功率密度分别为36.03和 6.32 mW/m2,简单底物的输出电压和功率密度高于复杂底物. MFCs在产电同时还可有效去除水中的有机物,288 h时以乙酸钠和淀粉为底物的MFCs中TOC的去除率分别为91.15%和83.20%,NH₃-N的去除率分别为90.31%和86.20%. 扫描电镜发现,2种底物下MFCs阳极表面的微生物形态差异显著,以乙酸钠为底物的MFCs阳极表面生物相主要为杆菌和弧菌;以淀粉为底物的阳极表面主要是球菌,表明不同底物条件下MFCs中所形成的微生物优势种群也不同.      

全自动淋洗-智能蒸馏联合技术检测土壤中阳离子交换量

针对土壤中阳离子交换量检测国标方法的不足,介绍了一种全自动淋洗法结合自动智能一体化蒸馏的联合技术。通过对实际样品和6种土壤标样的比较实验,表明,淋洗时间设置为20 min、乙醇洗涤次数设置为4次、蒸馏液质量设置为130 g较佳,在该条件下,土壤标样及实际样品的相对标准偏差(0.87%~1.07%)远小于行业标准方法的标准偏差(3.87%~5.18%),方法准确度也均在保证值范围内。该方法自动化程度高、可操作性强且检测结果的准确度、精密度及重现性都符合标准规定,可满足大批量土壤样品分析要求。     

Fabrication and characterization of electrospun porous cellulose acetate nanofibrous mats incorporated with capric acid as form-stable phase change materials for storing/retrieving thermal energy

Electrospun cellulose acetate (CA) nanofibrous mats incorporated with capric acid was studied to fabricate form-stable phase change materials (PCMs) for storing/retrieving thermal energy. Electrospun CA nanofibrous mats with different porous structures and specific surface areas were firstly prepared through regulating the volume ratio of mixture solvent of acetone/dichloromethane (DCM). Effects of different volume ratio of mixture solvent and mat thickness on the morphological structure, specific surface area, and absorption capacity of CA nanofibrous mats were systematically investigated. The results indicated that CA nanofibrous mats were highly porous on the surface; hence, they were capable of absorbing a large amount of capric acid. The maximum absorption capacity of CA mats via electrospinning with volume ratio of acetone/DCM being 5/5 was ~95.8 wt%, due to its higher specific surface area of ~17.1 m²/g. The specific surface area and capric acid absorption capacity of CA nanofibrous mats increased with the increases of mat thickness. As the thickness of nanofibrous mats increased from 10 to 85 μm, the corresponding specific surface area and capric acid absorption capacity of mats increased respectively from 7.2 to 29.0 m²/g and 92.1 to 98.5%. Morphological structures, as well as the properties of thermal energy storage and thermal insulation of the fabricated form-stable PCMs, were studied by scanning electron microscopy, differential scanning calorimetry, and measurement of freezing times, respectively. The results indicated that the resulting form-stable PCMs could well maintain their phase transition characteristics and demonstrated great thermal energy storage capability and temperature regulation ability.     

气相色谱法同时测定室内空气中乙苯和乙酸丁酯研究

建立了用气相色谱法同时测定室内空气中乙苯和乙酸丁酯的方法。乙苯和乙酸丁酯经活性炭吸附,二硫化碳解吸,DB～200毛细管柱分离,直接进样分析,氢火焰离子化检测器检测,时间定性,峰面积定量,乙苯回收率为95．3％-105．5％、乙酸丁酯回收率为94．8％-104．8％,当采样体积为30L,乙苯最低检出质量浓度为0．002m∥m。,乙酸丁酯最低检出质量浓度为0．003mg／m’。本方法前处理简便,分离度好,分析灵敏度高,满足室内环境分析要求。     

Investigation of suitable precursors for manganese oxide catalysts in ethyl acetate oxidation

The control of ethyl acetate emissions from fermentation and extraction processes in the pharmaceutical industry is of great importance to the environment. We have developed three Mn₂O₃ catalysts by using different Mn precursors (MnCl₂, Mn(CH₃COO)₂, MnSO₄), named as Mn₂O₃-Cl, -Ac, -SO₄. The tested catalytic activity results showed a sequence with Mn precursors as: Mn₂O₃-Cl > Mn₂O₃-Ac > Mn₂O₃-SO₄. The Mn₂O₃-Cl catalyst reached a complete ethyl acetate conversion at 212℃ (75℃ lower than that of Mn₂O₃-SO₄), and this high activity 100% could be maintained high at 212℃ for at least 100 hr. The characterization data about the physical properties of catalysts did not show an obvious correlation between the structure and morphology of Mn₂O₃ catalysts and catalytic performance, neither was the surface area the determining factor for catalytic activity in the ethyl acetate oxidation. Here we firstly found there is a close linear relationship between the catalytic activity and the amount of lattice oxygen species in the ethyl acetate oxidation, indicating that lattice oxygen species were essential for excellent catalytic activity. Through H₂ temperature-programmed reduction (H₂-TPR) results, we found that the lowest initial reduction temperature over the Mn₂O₃-Cl had stronger oxygen mobility, thus more oxygen species participated in the oxidation reaction, resulting in the highest catalytic performance. With convenient preparation, high efficiency, and stability, Mn₂O₃ prepared with MnCl₂ will be a promising catalyst for removing ethyl acetate in practical application.     

醋酸乙烯生产过程废触媒的资源化回收

采用正交实验研究了微波、超声波条件对废触媒解吸效果的影响，对比实验结果表明，1次微波2次超声波联用技术锌的洗脱率较高，回收的活性炭超过了林业局粉状活性炭二级品指标。用洗脱的醋酸锌溶液制备的磷酸锌符合防锈颜料要求。最终的废液采用电石废渣中和后达到国家废水处理三级排放标准。实现了废触媒的综合回收利用。     

废水产氢产酸／同型产乙酸耦合产酸条件优化

为了更好地发挥产氢产酸／同型产乙酸耦合系统在废水厌氧发酵生产乙酸方面的优势,有必要寻找一种简单有效的方法以获得该系统产酸的优化条件。利用经过加热处理并活化的厌氧污泥作种泥,以模拟废水中的葡萄糖为底物,针对发酵时间、底物浓度、种泥浓度、初始pH进行4因素10水平均匀设计实验,得到了乙酸生产指标与产酸条件之间关系的回归方程;也得到了以高乙酸产量为主要目标导向同时兼顾高乙酸产率和高乙酸生产强度目标的优化条件;优化条件实验乙酸浓度比均匀设计中最高乙酸浓度提高20％左右。研究表明,将均匀设计应用于废水产氢产酸／同型产乙酸耦合产酸条件优化,可以避免盲目性,迅速获得满意结果。