JHC－1型COD自动检测仪在污水处理场的应用

选用ＪＨＣ一且型ＣＯＤ自动检测仪对生化进口的ＣＯＤ值连续在线监测，在一年多的运行中检验了仪器的检测精度和准确度，并根据仪器的现场运行情况对仪器进行了一些完善，使之能较好地运行在实际生产中．     

凤眼莲生态工程在炼油废水深度处理中的应用研究

在炼油废水氧化塘中建设凤眼莲生态工程。该工程较显著地提高出水水质及透明度，对其中污染物质均有不同程度的去除能力。在炼油废水氧化塘中实施凤眼莲生态工程的最佳运行控制条件为：６５ｍｇ／Ｌ≤ＣＯＤ≤１３１ｍｇ／Ｌ，最高临界ＣＯＤ为２６３ｍｇ／Ｌ，故凤眼莲生态工程适用于炼油废水的深度处理。对凤眼莲去除炼油废水中污染物的机理进行了初步探讨。     

单位波长吸光度改变量-分光光度法优化后用于减小浊度对废水中Cr(Ⅵ)检测结果的影响

对基于单位波长吸光度变化幅度与被测物浓度间关系的单位波长吸光度改变量-分光光度法进行了优化,使其在减小样品浊度对检测结果影响方面的效果得到进一步提高,以获得更高准确度的检测结果。以570~590 nm拟合波长段为例,筛选不同的参比波长段,筛选依据主要为模拟浊度梯度样品的检测结果、回收率及其RSD。结果表明,当参比波长段分别为540~555 nm、540~560 nm、540~565 nm和540~570 nm时,可获得非常好的方法检出限(1.0~1.6μg/L),加标样品结果具有良好的准确度(回收率为79.8%~111%)、精密度(RSD为0.15%~32%)。     

Assessment of the temporal and spatial distribution of atmospheric PCNs and their air–soil exchange using passive air samplers in Shanghai,East China

A total of 47 passive air samples and 25 soil samples were collected to study the temporal trend, distribution, and air–soil exchange of polychlorinated naphthalenes (PCNs) in Shanghai, China. Atmospheric PCNs ranged from 3.44 to 44.1 pg/m³ (average of 21.9 pg/m³) in summer and 13.6 to 153 pg/m³ (average of 40.0 pg/m³) in winter. In the soil samples, PCN concentrations were 54.7–1382 pg/g dry weight (average of 319 pg/g). Tri-CNs and tetra-CNs were two dominant homolog groups in air samples, while di-CNs were also found at comparable proportions to tri-CNs and tetra-CNs in soil samples. Most air and soil samples from the industrial and urban areas showed higher PCN concentrations than those from suburban areas. However, some soil samples in urban centers presented higher PCN concentrations than industrial areas. Analysis of PCN sources indicated that both industrial thermal process and historical usage of commercial PCN mixtures contributed to the PCN burden in most areas. The fugacity fraction results indicated a strong tendency of volatilization for lighter PCNs (tri- to hexa-CNs) in both seasons, and air–soil deposition for octa-CNs. Moreover, air–soil exchange fluxes indicate that soil was an important source of atmospheric PCNs in some areas. The results of this study provide information for use in the evaluation of the potential impact and human health risk of PCNs around the study areas.

     

Suspension Polymerization of Poly(l-lactide-co-p-dioxanone) in Supercritical Carbon Dioxide

Biodegradable copolymers of l-lactide(l-LA) and p-dioxanone(PDO) were synthesized in supercritical carbon dioxide (scCO₂) with stannous octoate as the ring-opening catalyst and a fluorocarbon polymer surfactant as an stabilizer. Fine powderous products were achieved when more than 90% (w/w) l-LA was fed. Scanning electron micrographic images and laser diffraction particle size analysis of the products showed the mean diameter of particles greatly increased as the content of PDO increased. The obtained polymers had the number-average molecular weights ranging from 15,000 to 26,000 g mol⁻¹ (polydispersity index ranging from 1.3 to 2.1) according to the gel permeation chromatography measurements. The polymer structure was characterized by NMR spectroscopy, indicating the formation of copolymers. Thermal properties of the obtained polymers investigated using differential scanning calorimetry showed that the morphology of products was directly relevant to the crystallinity of the copolymers. The polymerization of l-LA and PDO copolymers in scCO₂ is also proposed as a novel production technique for high-purity, biodegradable polymers.     

Synthesis and Properties of Poly(d,l-lactide-co-p-dioxanone) Random and Segmented Copolymers

Two different polymerization routes, one-step and two-step bulk ring-opening polymerizations of d,l-lactide (LA) and p-dioxanone (PDO) monermers using stannous octoate [Sn(Oct)₂]/n-dodecanol as the initiating system, were employed to synthesize poly(d,l-lactide-co-p-dioxanone) P(LA-co-PDO) random and segmented copolymers with different compositions and chain microstructure. For the two-step copolymers, the average sequence lengths of the lactidyl (L_LA) and dioxanyl (L_PDO) units calculated from the ¹H-NMR spectra were much longer than those values for the one-step copolymers with the same LA/PDO feed ratio. Corresponding to this difference in microstructure, the two-step copolymers were semi-crystalline even when the PDO content was as low as 14.5 mol%, while the one-step copolymers were completely amorphous with PDO content below 60.6 mol%. However, irrespective of polymerization route, both types of copolymers displayed a single glass transition temperature that was in a linear relation with composition. The decrease of maximum decomposition temperature of the copolymers was in accordance with the decrease of L_PDO value. The mechanical and degradation properties of the copolymers were significantly affected by both the polymerization route and the chemical composition as well. In conclusion, the properties of P(LA-co-PDO) copolymers could be adjusted conveniently to meet specific applications by changing the composition and microstructure of the copolymers via different polymerization routes.     

生物流化床处理含硫污水净化水的探讨

主要从生物流化床小试装置的建立、运行启动、载体和停留时间的选择以及相关的问题进行了试验探讨．     

MBR污水处理技术在炼油污水中的应用

膜生物反应器（MBR）是膜技术和污水生物处理技术相结合的污水处理新工艺。金陵分公司污水处理场新建一座MBR处理装置，处理量为250t／h，自2005年11月正式投用，至今已连续运行一年的时间。该装置对炼油污水COD、油、硫、酚、氨氮、浊度的平均去除率分别稳定在80％、60％、100％、98％、90％、99％以上。为炼油污水回用创造了条件。     

浅谈如何落实"一把手"安全责任

随着社会对安全生产重视程度的不断提高,“一把手”抓安全、负总责已是企业的普遍做法。事实上,“一把手”在抓安全的过程中,还存在着不少误区和形式主义,致使“一把手”抓安全的力度和效果大打折扣。本文以油田企业为例,提出全面有效落实“一把手”责任制应采取的措施。