煤热解过程中无机有害元素的变迁规律

在自行设计的加压密闭快速热解反应器中研究了神华和义马煤中Na、K、Pb和Mn等无机有害元素在氮气条件下随温度（300℃-700℃)的变化规律,进一步考察了热解气氛（氮气、氢气和二氧化碳）、压力对神华煤中这4种元素逸出规律的影响。结果表明：Na、K、Pb和Mn等元素在半焦中的残留量随温度的升高而减少,减少量随煤种而异,如在700℃时,神华煤中Na、K、Pb和Mn的析出率分别是义马煤的3、4．2、1．4和2．4倍;低压快速加氢热解有利于这4种元素的逸出。Pb是挥发性最强的元素,与热力学计算结果一致。     

用微波炉溶解分析样品

<正> 不久前我们发表了一个联合多种技术分析煤和煤飞灰中多种元素的方案。在该方案中,犬部分元素是在用Parr酸分解弹(一种带钢套的聚四氟乙烯耐压密封容器)溶解样品后进行测定的。这个方法需要预先在马弗炉(8小时)或低温射频灰化器(3天)中灰化煤样,然后将灰份混合酸在Parr弹中加热约两小时,进行溶解。虽然我们的实验室和其他实验室已经普     

Gas chromatographic separation and determination of chloroanthracene isomers on fly ash

An efficient, reproducible and rapid fused silica capillary column gas chromatographic method, in splitless mode, for analysing of the three chloroanthracene isomers is described. The method affords efficient separation and good linearity for each isomer in the range of 0.2 -200 μg/ml. The method can also be used in separation and determination of another thirty three aromatic and their halosubstituted compounds. This paper also presents the applications of the method in analysing of complex products mixture from reaction of the selected aromatic compounds with hydrogen chloride on fly ash surface from municipal incinerator.     

加拿大制浆造纸废水厌氧处理的进展

1960～980年间,加拿大用于清除制浆造纸工业污染的经费约达6.6亿美元。采取这些措施后,到1980年加拿大72％的制浆造纸厂达到了国家控制废水BOD排放的规定。进一步改进达标状况的措施之一是对许多新制浆厂的高浓度废水采用厌氧处理技术。但需首先要了解制浆造纸工业在采用厌氧技术以前,在几方面的数据(表1)。 1.制浆造纸废水的适应性、生化可降解性及毒性     

酸雨的大气物理化学机理

1.输送过程中的化学转化对北美洲雨水样品的分析表明:雨水的酸度在很大程度上取决于它的硫酸盐和硝酸盐离子浓度,因此本文将着重讨论这两种污染物的形成过程。虽然,大气中有少量的硫酸盐和硝酸盐是被直接排放出来的,但据认为,降雨中这两种盐类的主要来源是硫氧化物和氮氧化物的进一步氧化。然而在燃油发电厂和炼油厂附近,硫酸盐的直接排放量还是较大的。由上述情况可以看出,了解排放点和接受点之间排     

24、用电化学和紫外检测的高压液相色谱法测定卤代苯胺及有关化合物

卤代苯胺可以从各种渠道包括农药、除莠剂、杀菌剂的代谢作用,工业废料和硝基取代芳香化合物的还原而进入环境中。由于苯胺类化合物有毒所以要求在环境中监测。以前用气相色谱法,需要进行衍生化;而且某些被卤代的代谢物还不能被分离。本文研究的高压液相色谱法可在无衍生化步骤的情况下进行分离,并检测出亚毫微克量的物质。这些化合物是用商品c-18键合相柱分离的,并用价廉的电化学检定器检测至亚毫微克量级。同时还研究了快速但灵敏度很低的紫外线方法。列举了各种化合物的色谱图和灵敏度数据。讨论了电化学检定的应用和限度。     

大孔强碱阴树脂去除饮用水中微量有机物

比较了大孔强碱阴树脂和颗粒活性炭在饮用水的深度处理中对有机物的去除效果。结果表明：(1)大孔强碱阴树脂的吸附容量比颗粒活性炭的大。在pH为8时,大孔强碱阴树脂对TOC的去除率最高。pH6～8时,对TOC的去除率没有明显的区别,而颗粒活性炭在pH为2时。对TOC的去除率最高;水温低能提高2种吸附材料的吸附容量。(2)在动态实验条件下。当流速相同,大孔强碱阴树脂的穿透时间明显比颗粒活性炭的长,大孔强碱阴树脂的制水量约是吸附床的10000倍。而颗粒活性炭却只有吸附床的4000倍。在饮用水的深度处理中,大孔强碱阴树脂可作为活性炭的最佳替代品。     

Persistent organochlorine residues in soils from tropical and sub-tropical Asian countries

Soil samples from paddy fields, uplands, and urban areas (gardens and roadsides) collected from Vietnam, Thailand, and Taiwan were analysed to determine the residual levels of persistent organochlorine compounds such as DDTs, HCHs, and PCBs. DDT concentration in soil samples from Vietnam were found to be highest, with a mean value of 110 ng g(-1), and were followed by those in Taiwanese soils with a mean value of 20 ng g(-1). HCH concentrations were highest in soil samples from Vietnam (a mean value of 4.8 ng g(-1)) and were followed by those from Taiwan (a mean value of 1.4 ng g(-1)). Concentrations of PCBs were found to be highest in Taiwanese soil samples, with a mean of 95 ng g(-1). Interestingly, relatively high concentrations of PCBs in rural cultivated-soil samples from Vietnam were recorded with a mean value of 25 ng g(-1), probably suggesting PCB release from different kinds of weapons used during the Second Indochina war. The lowest concentrations of DDTs, HCHs, and PCBs were obtained in soil samples from Thailand, with mean values of 8.3 ng g(-1), 0.4 ng g(-1), and 2.7 ng g(-1), respectively.     

Some epidemiologic features of disasters in guatemala

Epidemiological procedures can be organised under disaster conditions by means of a simple surveillance system and with few personnel.
In the aftermath of the 4 February 1976 earthquake in Guatemala, an information system was organized by which the requisite information for decision-making was obtained with adequate speed and promptness.
The initial epidemiologic informution was based on reports collected during the early days on symptoms observed at hospitals and health centers and in localities and villages in the stricken area.
At a second, post-emergency stage a more elaborate surveillance system was instituted to provide guidance in the investigntwn of outbreaks, evaluate the health activities and establish basic criteria for preventive and control measures.