纳米TiO2/活性炭复合光催化剂的制备及其对甲醛气体降解

研究了纳米TiO2/活性炭复合光催化剂对空气中典型污染气体甲醛的光催化降解特性。采用扫描电镜(SEM)表征复合催化剂的表面特征。结果显示,经改性后的纳米TiO2在复合催化剂表面分布均匀,呈球状。对甲醛气体的降解实验显示TiO2负载量为1%时对甲醛的去除效果最好,6 h去除率为61.7%。结果显示复合催化剂把甲醛气体分解成CO2,可以直接排空,无二次污染。     

甲醛生产火灾爆炸危险性分析、评价及安全措施

在分析甲醛生产过程中火灾爆炸危险因素的基础上,运用美国道化学公司的火灾、爆炸危险指数评价方法对甲醛生产装置进行了安全性评价。针对其工艺情况,对其中的氧化单元从一般工艺危险性、特殊工艺危险性和安全补偿措施等方面进行系统分析与评价,并根据评价结果,提出了预防事故的安全措施,为甲醛的安全生产与管理提供了切实可行的参考。     

汽车乘务舱半物理环境模拟的甲醛光净化效果分析

汽车乘务舱半物理环境模拟系统,以测试室作为汽车乘务舱的模拟环境,采用平衡子系统作为甲醛污染物生成装置,用于研究在不同条件下甲醛污染物的光净化效果。实验结果表明:良好的通风条件可以改善甲醛的降解效果;甲醛初始浓度升高后虽然其降解效果有所下降,但是降解效果仍然可以达到80%以上;用改变电压来改变光强,9V和12V不同光强条件下,12V的效果好于9V;光照面积的增加可以明显地改善光催化降解的效果;玻璃和皮革作为载体时,皮革载体的降解效果要远好于玻璃载体。实验研究证明,光净化材料完全可以应用于汽车内环境中,且对甲醛空气污染物具有良好的净化效果。     

Fenton氧化-生物接触氧化工艺处理甲醛和乌洛托品废水

采用Fenton氧化一生物接触氧化工艺处理含甲醛和乌洛托品的模拟废水（简称废水），在H2O2（体积分数30％）加入量2．5g／L、H2O2与Fe^2＋质量浓度比3．75、反应时间3h、不调节废水初始pH的Fenton氧化预处理最佳操作条件下，废水COD从1000mg／L左右降至300mg／L，COD去除率达72％。原废水完全无法直接进行生化处理，经Fenton氧化预处理后其BOD，／COD约为0．5，易于生化处理。Fenton氧化一生物接触氧化工艺处理废水，生物接触氧化停留时间为12h时，废水COD去除率高达94％，处理后出水COD小于70mg／L，处理效果很好。     

催化臭氧氧化法处理甲醛废水

用异丙醇钛盐表面改性法制备TiO2／SiO2催化剂，对甲醛废水进行催化臭氧氧化处理。通过比表面积的BET测定法、X射线衍射和拉曼光谱等分析方法对TiO2／SiO2催化剂进行了表征，考察了TiO2／SiO2催化剂加入量、臭氧流量及溶液pH等因素对甲醛催化臭氧氧化效果的影响。实验结果表明，在SiO2表面，TiO2微晶粒子以锐钛矿型高度分散；在甲醛质量浓度700mg／L、COD1000mg／L、TiO2／SiO2催化剂加入量2．0g、臭氧流量2．5mg／min、溶液pH8．5的条件下，催化臭氧氧化反应30min后，甲醛质量浓度由700mg／L降至39mg／L，COD去除率认到87．5％．     

示波极谱测定空气中甲醛含量的方法及其应用

本文研究了用示波极谱测定室内空气中甲醛含量的方法，其结果为：本法测定甲醛的检测下限为３４μｇ／Ｌ，加标回收率为８７５～１１００％，变异系数为４２５～８６３％，该法灵敏度高，甲醛含量与极谱峰高的线性关系好，是一种可靠的测定室内空气中甲醛含量的方法。同时还研究了缓冲液的ｐＨ值及吸收液放置时间对甲醛测定结果的影响，并将该法应用于评价空气净化器去除室内空气中甲醛的效果。     

室内空气中的甲醛检测及控制

随着人们对居室装修要求的不断提高，人造板及油漆等在室内装修中已经广泛使用，随之而来的是由于装修引起的室内空气化学污染问题，室内空气中有害化学物质对人们身体健康的危害也越来越大，其中甲醛对人体的危害尤为严重。室内空气中甲醛的检测及控制已经得到各发达国家和国内的高度重视，对甲醛的检测和控制技术的改进也成为社会各界普遍关注的问题。     

Kinetics of hydrogen peroxide-sulfur (IV) reaction in atmospheric precipitation

The kinetics of the reaction of dissolved S(IV) with H2O2 was studied on 59 precipitation samples collected in Southwestern China, during the period of June 1988 to October 1989, from which the oxidation rates of the reaction were measured. The extent of reaction was followed by continuous amperometric measurement of the concentrations of the reagents. The two systems (i. e. rainwater and purified water) have been studied with the same methodology under identical reaction conditions (e. g. reagent concentrations, ionic strength and temperature). The kinetics was studied in no buffer solutions. The effect of formaldehyde on the reaction has also been studied, including kinetic studies in laboratory and model calculations, and it is indicated that formaldehyde with typical atmospheric concentration exerts no influence on the reaction of dissolved S(IV) with H2O2. In addition, the activation energy of the reaction was also measured in purified water as reaction medium for temperature range 0-50℃ at pH 4.0     

Application of cleaner production technology in chemical industry: a near zero emission

The main objective of this study is to investigate and evaluate opportunities for implementation of pollution prevention and waste minimization in a chemical industrial company producing poly sulfonated naphthalene formaldehyde which is used as a super plasticizer for concrete. Environmental problems encountered were mainly the highly polluted wastewater and a semi-solid cake containing considerable amount of the final product. Possible modules for remedial measures and their cost estimation were investigated. The proposed remedial modules included recycling of retained water discharge in filter press, recycling of washing water of reaction vessels (reactors), closed circuit cooling system for high-pressure pump, good housekeeping through control of leakage of raw material, products and water and finally utilization of retained residual product from the solid waste. The implemented pollution control measures proved to be cost effective and have short payback periods. Also, minimization of the hydraulic and organic loads in the final effluent was achieved.     

Carbonyls in the metropolitan area of Mexico City: calculation of the total photolytic rate constants Kp(s(-1)) and photolytic lifetime (tau) of ambient formaldehyde and acetaldehyde

A great number of studies on the ambient levels of formaldehyde and other carbonyls in the urban rural and maritime atmospheres have been published because of their chemical and toxicological characteristics, and adverse health effects. Due to their toxicological effects, it was considered necessary to measure these compounds at different sites in the metropolitan area of Mexico City, and to calculate the total rate of photolytic constants and the photolytic lifetime of formaldehyde and acetaldehyde. Four sites were chosen. Sampling was carried out at different seasons and atmospheric conditions. The results indicated that formaldehyde was the most abundant carbonyl, followed by acetone and acetaldehyde. Data sets obtained from the 4 sites were chosen to calculate the total rate of photolysis and the photolytic lifetime for formaldehyde and acetaldehyde. Maximum photolytic rate values were obtained at the maximum actinic fluxes, as was to be expected.