四川安宁河流域水化学特征及物源探讨

安宁河河谷地区是四川省第二大粮仓,区内人口较多、矿业发达。查明流域水化学特征及物质来源,对于探讨地质背景与人为活动对河流水化学特征的影响具有重要意义。研究显示,安宁河河水整体偏弱碱性,pH均值为8.18,TDS值高于世界河流平均值。河水中阳离子浓度平均值顺序为Ca²⁺ > Na⁺ > Mg²⁺ > K⁺,阴离子浓度平均值顺序为HCO₃^- > Cl^- > SO₄^2- > NO₃^-。空间上,自上游至下游,安宁河河水的TDS值和阴阳离子含量呈整体上升的趋势,SO₄^2-、NO₃^-浓度波动较大。控制流域水化学特征的主要因素是硅酸盐岩的风化,其次是碳酸盐岩的风化。流域内的NO₃^-主要来源于农业活动和土壤有机氮,矿业活动对安宁河河水中SO₄^2-浓度的影响较大,人为活动对安宁河流域水化学的影响不可忽视。     

湛江东海岛海雾雾水化学特征的对比分析

利用2010年和2011年在广东省湛江市东海岛海雾外场观测试验中获得的雾水样本和雾滴谱资料,对南海沿岸海雾化学特性进行研究.结果表明:2010年雾水的p H和电导率(EC)平均值分别为5.20和1884μS·cm-1,2011年的p H和EC平均值分别为3.34和505μS·cm-1.2011年雾水酸性变强的原因主要考虑到酸性物质比重增加.海洋源离子Cl-和Na+的离子浓度很高;SO_2-4和NO-3具有同源性,人为污染的贡献明显.2010和2011年总离子浓度(TIC)的平均值分别为38260μeq·L~(-1)和5600μeq·L~(-1),而实际大气中离子负荷量相差不大,主要是由于2011年观测地点海拔高度的升高会降低湍流因子的影响,减少粒径较大雾滴的沉降,从而促使液态水含量增加,在大气中污染物质浓度变化不大的情况下,离子浓度下降.     

In situ monitoring of atmospheric nitrous acid based on multi-pumping flow system and liquid waveguide capillary cell

In the last four decades, various techniques including spectroscopic, wet chemical and mass spectrometric methods, have been developed and applied for the detection of ambient nitrous acid (HONO). We developed a HONO detection system based on long path photometry which consists of three independent modules i.e., sampling module, fluid propulsion module and detection module. In the propulsion module, solenoid pumps are applied. With solenoid pumps the pulsed flow can be computer controlled both in terms of pump stroke volume and pulse frequency, which enables the attainment of a very stable flow rate. In the detection module, a customized Liquid Waveguide Capillary Cell (LWCC) is used. The customized LWCC pre-sets the optical fiber in-coupling with the liquid wave guide, providing the option of fast startup and easy maintenance of the absorption photometry. In summer 2014, our system was deployed in a comprehensive campaign at a rural site in the North China Plain. More than one month of high quality HONO data spanning from the limit of detection to 5 ppb were collected. Intercomparison of our system with another established system from Forschungszentrum Juelich is presented and discussed. In conclusion, our instrument achieved a detection limit of 10 pptV within 2 min and a measurement uncertainty of 7%, which is well suited for investigation of the HONO budget from urban to rural conditions in China.     

惰性物对爆炸的遏制

利用爆炸激波管技术研究了部分惰性物对爆炸特性的影响。用多通道辐射高温计测量了氮气对汽油爆轰温度的影响。研究表明，增加氮气含量可以较明显地降低汽油爆轰温度。采用化学当量配比氢氧混合物爆轰产生水蒸气的方法研究了水蒸气对汽油爆轰特性的影响。研究表明，水蒸气能明显降低爆炸压力，水蒸气压力增加到0．1MPa时可导致爆炸熄灭；硝基甲烷和氧气混合物中充人氮气后爆炸压力明显下降，采用光多通道分析系统(OMA谱仪)和多台单色谱仪的光谱测量结果表明，反应中间产物的CH3O、CH辐射强度迅速衰减，反应衰竭。     

Selecting safer building products in practice

In recent years the green building movement has focused increased attention on chemical hazards in building products and the need to select safer alternatives. This paper describes a number of tools available to architects and other building professionals and explores the product evaluation process behind one resource, BuildingGreen’s GreenSpec directory, as a window into the imperfect reality of alternatives assessment in the building design field.     

Observation of the nighttime nitrate radical in Hefei, China

Observation of nighttime nitrate radical (NO3) was performed by using long path differential optical absorption spectroscopy (LP-DOAS), on the outskirts of Hefei, China. The time series of NO3 and supporting parameters were simultaneously measured for a week (31 May-7 June 2006). The results indicated that the average concentration of NO3 was 15.6 pptv with an average lifetimes of 96 s, whereas, NO3 production rates varied from 8×105/(cm3·s)to 2.98×107/（cm3·s）. Furthermore, the calculated N2O5 concentration averaged at 380 pptv. Analysis of data indicated that direct sinks were probably dominating the NO3 loss process during this campaign. Finally, the results were compared with other campaigns in the boundary layer.     

浸渍活性炭脱除含硫气体研究进展

介绍了浸渍活性炭脱除含硫气体机理的研究进展,归纳了炭表面化学环境,金属离子及水对转化途径和反应机理的影响,对进气组成和温度、压力、空速等操作条件对脱硫效率的影响进行了讨论,举例说明了浸溃活性炭脱硫应用情况,分析了浸渍活性炭失活原因,对再生方法进行了简要总结。     

无机阴离子对电化学氧化降解水体中4-CP的影响

为了探讨废水中无机阴离子对电化学氧化降解对氯苯酚（4-CP）产生的影响。文章采用了自制圆形电化学反应器,通过改变模拟废水中电解质及其浓度来分析无机阴离子对4-CP去除率及矿化率的影响。试验研究表明,当废水中以OH-为主且浓度约为0.01 mol/L时,4-CP去除率可达81.99%,矿化率最高可达38.09%,而电化学能耗最低仅为35.57 kWh。     

溴氰菊酯在海水养殖区沉积物中的化学降解规律

以水产养殖中应用广泛的溴氰菊酯农药作为研究对象,通过室内生态实验,模拟和分析了溴氰菊酯农药在乳山湾养殖区沉积物环境中的化学降解行为。溴氰菊酯农药在乳山湾沉积物中的化学降解符合一级动力学方程Ct=C0e-kt,根据一级反应原理,模拟其降解方程,得出在符合动力学反应阶段的速率常数(k)。计算出化学降解的半衰期在66.7~72.8 d。化学降解的速率常数与温度均呈正相关,均随温度的升高而增大。     

基于胶体化学和乳状液理论分析乳状液脱稳破乳机理及方法

乳状液中含有大量的油类和表面活性剂,并以微细的颗粒液珠高度分散在水中,具有相当的稳定性,根据胶体化学和乳状液理论,分析乳状液稳定的原因,从而提出相应的对其进行脱稳破乳除油的方法,这是处理乳状液废水的关键之所在,对乳状液的治理具有重要意义.