国内硝基苯废水治理研究进展

硝基苯的高毒性、难降解性及其在环境中的积累性，使得硝基苯污染治理成为众多科研工作者关注的课题，本文综述了国内治理硝基苯污染的方法原理，研究进展及今后深入研究的方向。     

不同电解质条件下硝基苯废水的处理研究

实验研究了不同电解质条件下硝基苯的处理研究,发现用NaCl作电解质电解后的溶液中没有苯胺,经研究证明是因为溶液中的氯离子在电解过程中生成活性氯,活性氯对有机物有很强的氧化作用,所以快速与生成的苯胺反应,将其氧化或转化为其它有机物及小分子,使电解效果明显提高。     

EXCESS GIBBS ENERGY FOR THE BINARY MIXTURES OF NITROBENZENE WITH SOME HYDROCARBONS AT 94.95KPA

Bubble point temperatures at 94.95 kPa, over the entire composition range, are measured for the binary mixtures of nitrobenzene with: cyclohexane, n-hexane, n-heptane, n-decane, and o-, m-, and p-xylenes, using a Swietoslawski-type ebulliometer. Liquid phase composition versus bubble point temperature measurements are well represented by the Wilson model. Computed values of the excess Gibbs energy are presented and discussed.     

Biodegradability Improvement of Aqueous 2,4-Dichlorophenol And Nitrobenzene Solutions By Means of Single Ozonation

The possibility of the integration of ozonation and biological processes as an economical way to treat biorecalcitrant organic compounds such as nitrobenzene and 2,4-dichlorophenol was investigated. In the pre-treatment step, stoichiometric coefficients and pseudo first-order kinetic constants were obtained. Biodegradability was monitored throughout the ozonation step, in order to evaluate the optimum ozone doses. The low TOC reduction after these ozone doses allowed much of the organic carbon to be removed in the biological stage. In the case of 2,4-dichlorophenol, the biodegradability improvement was checked in an aerobic bioreactor. By means of the combined ozonation-biological oxidation, up to 80% of the initial organic content was removed. Results presented in this study show the feasibility of using the combination of ozone and conventional biological treatments to treat wastewaters containing these pollutants.     

Removal of 2,4,6‐Trinitrotoluene from “Pink Water” Using Molecularly‐Imprinted Absorbent

Molecularly‐Imprinted Polymers (MIPs) were designed, prepared, and tested for the removal of TNT from “pink water”, which contains 2,4,6‐trinitrotoluene (TNT) and other nitrobenzene compounds (NBCs) produced in army ammunition plants. We have investigated the interactions between TNT template and different monomers using molecular modeling and spectrometric methods, which enables us to optimize the MIP compositions. A suspension polymerization method was utilized to prepare MIP beads with an average diameter of 25 µm, and an imprinting effect of 4.3 was achieved. Furthermore, we have constructed a model absorbance reactor using a flash chromatography system, which was successfully used to monitor the removal of TNT and other NBCs on‐line, and the MIP absorbent was regenerated in‐situ. Compared with granular activated carbon, the capacity of the MIP absorbent is 65‐fold higher. In addition, the MIP absorbent can be regenerated easily, and the capacity only decreases by 7 % after four rounds of regeneration. Besides “pink water”, the MIP absorbent can also be used to remove NBCs in the waste stream from TNT production.     

Photocatalytic Oxidation Processes In The Presence Of Polymers

The objective of the study was to investigate the removal of synthetic organic compounds and THM precursors by two photocatalytic oxidation processes in the presence of synthetic polymers. H₂0₂/UV and O₃/UV processes were tested on solutions of nitrobenzene and aquatic fulvic substances in the absence and presence of Polyethylene Oxide (PEO) and a Betz Polymer. The presence of high concentrations of PEO reduced the removal rate of nitrobenzene by competing with it for hydroxyl radicals. The presence of low concentrations of PEO did not significantly alter the removal rate of nitrobenzene and THM precursors. Experimental results indicated that even in the presence of the polymers, decomposition rather than coupling was the favored reaction pathway.     

废水中苯胺测定方法的对比验证

对测定废水中苯胺的几个方法作了对比验证 ,试验表明 ,改进后的方法能达到与原来苯胺测定方法相类似的结果 ,误差在允许范围内。认为改进后的苯胺测定方法是可行的、适用的。     

Hydrogenation of Nitrobenzene over a Pd/Al2O3 Catalyst – Mechanism and Effect of the Main Operating Conditions

The catalytic hydrogenation of nitrobenzene (NB) was studied in a three‐phase basket reactor with a commercial Pd/Al₂O₃ sample as catalyst. The kinetic experiments allowed a better understanding of the mechanism behind the formation of aniline (ANL) and by‐products, a topic not yet well comprehended. The effect of some operating conditions was studied and the existence of more by‐products than mentioned in the literature was stated; specifically, benzene formation was verified. Both the reaction kinetics and selectivity were found to be strongly dependent on the temperature, while the effect of total pressure is not that pronounced. Moreover, the high selectivity of the catalyst used in the present work was proved, and as such the deep hydrogenation of ANL to form by‐products only occurs in considerable extension when the NB concentration in the reaction mixture becomes negligible.     

Efficient reduction of nitroarenes using supercritical alcohols as a source of hydrogen in flow-type reactor in the presence of alumina

Reduction of nitroarenes using supercritical alcohols as a source of hydrogen was studied in a flow reactor in the presence of alumina at temperatures 515–615 K and residence times not exceeding 6 min. In the reaction of nitrobenzene reduction by 4-methylpentan-2-ol in supercritical (sc) CO₂, the selectivity for aniline reached 95% with a conversion of 71%. If methanol was used as the reducing agent, the main reaction product was N,N-dimethylaniline. It was shown that the use of scCO₂ co-solvent had a significant impact on the course of the reduction process including secondary and side reactions. The conditions for the reduction of halogenated nitroarenes into respective amines with high conversion and nearly 100% selectivity almost without dehalogenation were found.     

硝基苯选择加氢制对氨基苯酚

研究了以０ ．８ ％ Ｐｄ／ Ｃ 为催化剂,硫化物为助催化 剂, 在酸性介质中硝基苯选择 催化氢化合成对氨基苯酚的反应条件。该反应 最佳条 件为：氢气 的压力 ０ ．２ Ｍ Ｐａ , 催化剂 用量为 反应物 质量的 １ ．２ ％ ,助催化剂与催化剂用量摩尔比为０ ．６ ,硫酸溶液的质量分数为１２ ％ ,阳离子表面活性剂０ ．４ ｍ Ｌ,反应温度为（８５ ±１） ℃,反应时间为８０ ｍｉｎ 。研究 结果表明,选用易回收、低浓度 的０ ．８ ％ Ｐｄ／ Ｃ 催化剂,对硝基苯氢化反应具有较高的活性,通过 添加助催化剂可明显提高 反应的选择性。合成产品通过 Ｉ Ｒ、 Ｍ Ｓ 确认其结构,并通过滴定氨基值计算出硝基苯的转化率为９０ ％ 左右,产品的选择性达８０ ％ 。该工艺生产成本比传统工艺低,工业污染小,操作简便,收率高,为工业化生产提供理论依据