固相萃取和液液萃取测定水中百菌清和环氧七氯

采用固相萃取与液液萃取测定水中的环氧七氯和百菌清,用带有电子捕获器检测器的气相色谱仪进行测定。百菌清液液萃取的回收率在57%-87%之间,固相萃取的回收率在87%-110%之间。环氧七氯液液萃取的回收率在50%-90%之间,固相萃取的回收率在83%-110%之间。固相萃取法的回收率更高,且方法检出限更低,完全满足《地表水环境质量标准》(GB 3838-2002)的要求。     

采用电导法快速测定不同水中硫酸根的含量

目前测定水中硫酸根的各种方法中，浓度较高时（如海水和卤水）采用硫酸钡重量法，浓度较低时采用比浊法、比色法和示波滴定法。本文采用氯化钡标准溶液滴定，电导法确定终点，方法快捷，准确度高，不受水样的浑浊度、色度等影响，适用于卤水、海水、自来水、深井水、雨水和部分工业废水中硫酸根的测定。     

纳氏试剂分光光度法与气相分子吸收光谱法测定地表水中氨氮

文章探讨了纳氏试剂分光光度法和气相分子吸收光谱法检测地表水中氨氮的方法,主要从工作曲线、准确度、加标回收率以及实际样品分析等方面分别对两种方法进行对比。经实验对比后发现,气相分子吸收光谱法与经预处理后的纳氏试剂分光光度法的分析数据无明显差异,具有一致性,适用于测定地表水中氨氮浓度。     

废水中氨氮测定的工作经验总结

水和废水中氨氮的测定方法通常有纳氏试剂比色法、气相分子吸收法、苯酚-次氯酸盐(或水杨酸-次氯酸盐)比色法和电极法。由于纳氏试剂比色法具有操作简便、灵敏等特点,可适用于地表水、地下水、工业废水、生活污水的测定,因此已成为目前国内外环境监测工作中普遍使用的标准方法之一。由于水样成分的复杂性,在实际操作中存在许多问题,从而影响了分析质量。本文就实验中经常出现的影响因素及其消除方法进行了分析和总结,以期能更好的指导工作。     

低色度工业废水处理

工业废水的排放量大,且有些工业废水中有色有机物含量较高,因而色度较高,经过初步处理后再进行深度处理的难度较大,目前所采用的处理方法一方面处理效果不理想,另一方面处理费用较高.文章通过研制新型的水处理剂处理低色度工业废水,效果较好.     

土壤中挥发性有机物提取方法的研究现状

挥发性有机物(VOCs)在土壤样品中残留浓度低且极易挥发,因此测定时选择合适的提取方法十分重要。文章对土壤中挥发性有机物(VOCs)的前处理方法进行阐述,归纳出当前土壤中挥发性有机物(VOCs)的几种提取方法及优缺点,并阐述提取方法的发展趋势。     

稀释接种法与微生物传感器快速测定法测定生化需氧量的分析比较

稀释接种法是生化需氧量的经典测定方法,该方法的缺点是时间较长,不能快速反映水体的污染状况,优点是可以准确测定各种地表水及工业废水。而生物传感器快速测定法则具有准确、快速测定的特点,缺点是对工业废水的测定具有选择性,对PH过高、过低、毒性大的废水测量误差较大。用上述两种方法测定标准样品、各种污水的生化需氧量进行差异性比较。     

顶空-气相色谱/质谱法测定固体废物中的挥发性有机物

研究采用顶空前处理技术处理固体废物,利用气相色谱质谱联用来分析测定固体废物中37种挥发性有机物(VOCs)。采用内标法绘制了校正曲线,各目标化合物5个浓度水平的响应因子的相对标准偏差均小于20%;测定了方法检出限,采用2g固体废物,各目标化合物方法检出限界于0.3~2.2μg/kg;对一种实际固体废物样品进行了加标回收实验,回收率范围30.9%~124%。     

前处理方法对测汞结果影响分析

通过测定三种前处理方法消解后水样中汞的浓度,分析了前处理方法对测定结果的影响,以及三种前处理方法的适用条件。     

永磁材料磨削集中供液工艺技术研究

文章阐述了一种适用于永磁材料磨削和清洗的集中供液系统的工作原理,解决了清洗废液环保处理的问题,实现了加工过程的污水零排放,同时提出了一种行之有效的固液分离工艺,降低了工人的劳动强度,提高了工作效率和生产安全性.     

固相萃取-高效液相色谱法测定地表水中微囊藻毒素-LR

建立了固相萃取-高效液相色谱法(SPE-HPLC)测定地表水中微囊藻毒素-LR(MC-LR)的方法。选择HLB固相萃取柱对水样进行富集,采用5%甲醇水溶液淋洗固相萃取小柱,然后使用甲醇完全洗脱。HPLC采用V(0.1%TFA):V(甲醇)=15:85混合溶液为流动相等度洗脱。该法的检测限为0.07ug/L。     

酚二磺酸分光光度法测定水中硝酸盐氮的条件控制

对酚二磺酸分光光度法测定水中硝酸盐氮进行了验证性的探讨,结果表明该方法具有测量范围较宽,显色稳定的优点,但此方法操作繁琐,尤其是对水样的前处理控制不好将对硝酸盐氮含量的测定影响较大。其线性区间在0.02-2.0mg/L范围内,相关系数等于0.9999,硝酸盐氮浓度小于0.02mg/L或大于2.0mg/L时,测量结果将产生一定的误差。     

Negotiating in a multi-plant company

While concluding that there is no rule of thumb method for determining the best structure for industrial relations procedures and negotiations in a multi-plant company, the author maintains that the main board has a vital role to play in developing a vigorous industrial relations policy, in disseminating information, and acting generally as a “guide, philosopher and friend” to the units in the group.     

超临界萃取技术在天然产物中的应用

超临界萃取技术是一种新型的分离技术,具有高效、快速、方便、安全、低能耗、环保、选择性好的特点,用它萃取天然产物中的有效成分已越来越引起人们的注意。文章介绍了超临界萃取的原理、特点及在天然产物开发与研究中的应用,并对其前景做了展望。     

土工实验中的液、塑限测定浅议

文章分析了当前土工实验中的液、塑限测定过程中应当注意的问题及其存在的问题,并论述了如何对其实验数据进行处理和分析的方法。     

A decision model for regional industrial recruitment and development

Although the practice of industrial recruitment is widespread among regions, its objectives and constraints are neither well established nor carefully evaluated in determining the most desirable industries. As a result, many regions frequently resort to a blind scramble for new industries. This paper suggests a decision model for a regional economy to determine the priority in industrial recruitment. The problem is formulated in terms of a mathematical programming model in which the objectives and constraints are explicitly stated. Regional input-output, table provides additional constraints in the model. The input-output table is also used in testing the economic feasibility of optimal solutions.     

电极液位传感器在蒸汽凝结水回收系统中的应用

干黄管液位控制在蒸汽凝结水回收系统中因凝结水温度高而产生老化、短路，故障率高，而采用不锈铜圆电极液位传感器控制液位，性能可靠，结构简单，节能效果显著。     

The Estimation of the Relationships between Water-Natural Gas Usage and Discharge-Emission Permission by Using Binary Logistic Model for the Industrial Establishments

The Thrace region is one of the most important agricultural and industrial regions in Turkey with its plain, deep and productive soil structure. The most important problem is industrial based water and air pollution in this region. In this study, 90 out of 541 establishments that use industrial water in the region were studied representing approximately 17% of the total population. The relationship between water-natural gas usage and discharge-emission permission is estimated by using the binary logistic model. In addition to the economic and social benefits, there are also economic and social losses due to environmental pollution because of the rapid industrialization in the Thrace Region. For example; the rice producers that use Ergene River for irrigation purposes lose efficiency and quality in various levels due to water pollution. According to the research results, an increase in wastewater is a factor that decreases the probability of obtaining discharge permission. Moreover, excessive use of underground water results in decreases in static and dynamic water levels in the region. Because of this result, it is more advantageous for sustainable water management to be directed to the sectors that do not use water for industrial purposes instead of the sectors that use water in their processes.