原油生产过程中的清洁生产管理

文章叙述了清洁生产的定义与发展,原油生产过程中的清洁生产管理,清洁生产前期工作,采油作业过程中的清洁生产,集输作业过程中的清洁生产,对基层单位原油生产过程中污染物的产生治理进行分析,提出了一些节能减排思路,为基层推行清洁生产管理提供参考。     

微量钒的分光光度测定方法研究进展

综述分光光度法测定试样中微量钒,并对各种方法的测量条件、特点以及应用范围作了较为详尽的论述和介绍。     

水溶液中盐的浓度与其电导率的关系研究

采用电导法研究了水溶液中盐的浓度与其电导率的关系。结果表明 ,在低浓度范围内电导率与浓度的平方根呈线性关系 ;在较高的浓度范围内 ,首次发现浓度与电导率的关系和 Langmuir吸附等温式中的压力与吸附量之间的关系类似。利用浓度与电导率间的定量关系确定水溶液中盐的浓度 ,比传统的重量法和滴定法快速且准确。     

Genotypic and environmental variation in chromium, cadmium and lead concentrations in rice

Genotypic and environmental variation in Cr, Cd and Pb concentrations of rice grains and the interaction between these metals were investigated by using 138 rice genotypes grown in three contaminated soils. There were significant genotypic differences in the three heavy metal concentrations of rice grains, with the absolute difference among 138 genotypes in grain Cr, Cd and Pb concentrations being 24.5-, 9.1- and 23.8-folds, respectively, under the slightly contaminated soil (containing 4.61mgkg(-1) Cr, 1.09mgkg(-1) Cd and Pb 28.28mgkg(-1), respectively). A highly significant interaction occurred between genotype and environment (soil type) in the heavy metal concentrations of rice grains. Cr concentration in rice grains was not correlated with Cd and Pb concentration. However, there was a significant correlation between Cd and Pb in slightly and highly contaminated soils. The results suggest the possibility to develop the rice cultivars with low Cd and Pb concentrations in grain.     

Polyelectrolyte enhanced ultrafiltration (PEUF) for the removal of Cd(II): effects of organic ligands and solution pH

This study focused on the effects of pH and organic ligands, namely ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and citric acids, on the removal and recovery of Cd(II) in polyelectrolyte enhanced ultrafiltration (PEUF). Polyethylenimine (PEI), which can bind with both positively charged metal ions by coordination bonding and negatively charged ligand-metal complexes by charge attraction, was employed as a chelating polymer. The removal and recovery of Cd species was greatly dependent on the chemistry of organic ligands according to solution pH, particularly being related to the distribution of Cd-ligand complexes at different pH levels. In the presence of EDTA, the dominant Cd species are negatively charged Cd(EDTA)(2-) and CdH(EDTA)(-) over the range of pH levels investigated, interacting with PEI via electrostatic attraction and being less pH dependent. On the other hand, the pH effects of both NTA and citric acid systems are similar to that for the system without organic ligands. This was associated with the fact that free Cd ions were predominant at the acidic pH range in both NTA and citric acid systems.     

水体中常见无机阴离子对TiO2薄膜光催化降解甲醛的影响

选择了5种水体中常见的阴离子(Cl-,SO2-4,HPO2-4/HPO2-4,HCO-3/CO2-3和NO-3),分别考查了其对TiO2薄膜光催化降解模拟甲醛废水的反应速率的影响;从上述离子的光吸收,对·OH的捕获及其生成的相应的无机自由基的氧化作用以及与甲醛的竞争吸附3个方面讨论了上述离子影响TiO2薄膜光催化降解模拟甲醛废水的反应速率的原因。结果表明,HCO-3/CO2-3对TiO2薄膜光催化降解甲醛具有抑制作用,Cl-和SO2-4的影响不大,H2PO-4/HPO2-4和NO-3具有促进作用。造成上述结果的主要原因是HCO-3/CO2-3具有很强的·OH捕获作用;Cl-,SO2-4对·OH捕获作用以及竞争吸附都较弱;H2PO-4/HPO2-4在TiO2表面具有较强的吸附能力,释放出的H+起到了酸催化剂的作用;NO-3在紫外光的照射下可以产生·OH,此外NO-3作为电子受体而降低了TiO2表面光生电子和空穴的复合几率。     

Relationship between atmospheric pollution processes and synoptic pressure patterns in northern China

The air pollution index (API) sequences in 10 cities in northern China and the synoptic pressure patterns during autumn and winter from 2002 to 2006 were analyzed with diagnostic and statistical methods. The results showed that the air qualities in northern China had a prominent correlation with the pressure systems. It revealed that (a) the increasing phase of API was associated with high pressure and the successive low pressure, (b) the preceding part of front (i.e. the retral part of low pressure) was associated with the maximum of API values during a cycle of air pollution process, (c) the pressure systems with high gradient led to the decrease of API, and (d) the synoptic pressure patterns and their evolvements were the main causes of regional air pollution processes. These relations can be used to analyze the variation characteristics and mechanism of regional atmosphere pollution process, and provide important basis for the qualitative prediction, control, and management of regional air pollution problems.     

序批式生物膜反应器同步硝化反硝化的曝气时问控制及其机制分析

装有鲍尔环填料的序批式生物膜反应器(SBBR)具有很好的同步硝化反硝化(SND)效果.从试验结果可以看出,SBBR具备了生成和保存内碳源以及产生缺氧区的良好条件;当硝化结束后,应立即停止曝气,可以降低出水TN并实现节能.分析了生物膜内各种基质、DO、聚β-羟基丁酸(PHB)的变化曲线.描述了生物膜内发生SND的过程和机制,并提出了SBBR中达到良好SND效果的曝气时间控制方式.     

La2O3/ZnO/TiO2光催化降解活性艳红K-2BP的研究

采用溶胶-凝胶法制备了La₂O₃/ZnO/TiO₂复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La₂O₃/ZnO/TiO₂的光催化性能。结果表明：当锌和镧的掺杂量w(ZnO)=20%, w(La₂O₃)=0.5%, 煅烧温度为500℃时,La₂O₃/ZnO/TiO₂复合光催化剂的光催化活性最高;当催化剂投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解效果最好。实验证明,La₂O₃/ZnO/TiO₂对活性艳红K-2BP的降解遵从Langmuir-Hinshelwood动力学模型,测得其反应速率常数k＝11.5 mg/(L·min);吸附常数K＝2.88×10^-2 L/mg。     

16种农药对东亚小花蝽的生态风险评估

东亚小花蝽是我国北方林木、果园和农田的优势天敌昆虫。为评估常用化学农药对东亚小花蝽的毒害作用,首次测定了16种田间常用化学农药对东亚小花蝽的24 h急性接触毒性,并进行了生态风险评估。结果表明所试除草剂、杀菌剂和杀虫剂中的吡蚜酮对东亚小花蝽较为安全,3倍田间最高推荐剂量下的校正死亡率低于33.33%。阿维菌素、甲氨基阿维菌素苯甲酸盐、吡虫啉和啶虫脒对东亚小花蝽的半数致死浓度LC0分别为36.567、15.798、4.992和4.487 mg a.i.·L~(-1)5,农田内风险可接受。噻虫嗪、联苯菊酯和呋虫胺对东亚小花蝽的LC_(50)分别为0. 002、0. 080和0. 968 mg a. i.·L~(-1),农田内危害商值分别为3 976.36、69.03和16.93,在农田内对东亚小花蝽造成的风险均不可接受。本研究的结果有助于合理施用化学农药以保护和利用东亚小花蝽。