狭窄海湾潮交换的分段模式Ⅱ.在象山港的应用

作者前文所建立的狭窄海湾潮交换的分段模式的合理性由矩形海湾数值计算结果得到验证，并被应用于象山港海湾水的更新周期估算     

First observation of different diffusion coefficients for two conformers in a neat liquid

 Self-diffusion coefficients were studied for the highly polar liquid N-methylformamide at pressures up to 200 MPa between the melting pressure curves and 420 K by the spin-echo method. N-Methylformamide exists as a mixture of two conformers in the neat liquid. These conformers have large differences at lower temperatures in their dynamic and structural properties. The self-diffusion coefficient of the cis-conformer being 17% lower than that of the trans-conformer at the same T and p. This is the first observation of such an effect. The experimental study is supported by Monte Carlo (MC) calculations which show that the first neighbors around a cis conformer are arranged differently than in an all trans liquid. The difference leads in the simulations to a much lower dielectric constant for the trans-cis mixture and might also explain the retardation of diffusion for the cis conformer. Received: 15 November 1999 / Accepted in revised form: 28 February 2000     

Predicting heavy metals’ adsorption edges and adsorption isotherms on MnO2 with the parameters determined from Langmuir kinetics

Although surface complexation models have been widely used to describe the adsorption of heavy metals, few studies have verified the feasibility of modeling the adsorption kinetics,edge, and isotherm data with one p H-independent parameter. A close inspection of the derivation process of Langmuir isotherm revealed that the equilibrium constant derived from the Langmuir kinetic model, K S-kinetic, is theoretically equivalent to the adsorption constant in Langmuir isotherm, K S-Langmuir. The modified Langmuir kinetic model(MLK model) and modified Langmuir isotherm model(MLI model) incorporating p H factor were developed. The MLK model was employed to simulate the adsorption kinetics of Cu(II), Co(II), Cd(II), Zn(II) and Ni(II) on Mn O2 at p H 3.2 or 3.3 to get the values of K S-kinetic. The adsorption edges of heavy metals could be modeled with the modified metal partitioning model(MMP model), and the values of K S-Langmuir were obtained. The values of K S-kinetic and K S-Langmuir are very close to each other, validating that the constants obtained by these two methods are basically the same. The MMP model with K S-kinetic constants could predict the adsorption edges of heavy metals on Mn O2 very well at different adsorbent/adsorbate concentrations. Moreover, the adsorption isotherms of heavy metals on Mn O2 at various p H levels could be predicted reasonably well by the MLI model with the K S-kinetic constants.     

Sulfide elimination by intermittent nitrate dosing in sewer sediments

The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S(nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.     

矿化垃圾处理垃圾浓缩液

介绍了利用矿化垃圾处理垃圾浓缩液,对各种污染物均有很好的去除效果,分析了对污染物去除率的影响因素,在试验基础上提出了相关的处理参数.     

油气勘探开发建设项目环境影响评价管理探讨

油气勘探开发建设项目存在滚动开发的特点,在近年来的环境影响评价管理实践中引发较多矛盾。文章分析了目前油气勘探开发建设项目环评管理中存在的环评要求不清晰、分类管理需细化、审查尺度不统一等问题,并从界定建设项目类型、明确环评开展时间和要求、明确环评文件编制类型、界定项目重大变更四个方面提出了改进油气项目环评管理的建议。     

FMEA和HAZOP在煤气柜风险分析中的综合应用

将故障类型和影响分析(FMEA)和危险和可操作性研究(HAZOP)相结合,对某电石生产企业的煤气柜设备和其涉及到的工艺的风险性进行了系统安全分析,并根据分析结果提出了针对性的控制措施。这两种分析方法各有所长,从不同角度系统全面地分析了潜在风险中的不安全因素,使其分析结果更加可靠、实用。     

磷石膏制硫酸钾中试研究

以湿法磷酸副产的磷石膏和工业品氯化钾为原料 ,采用两步法 ,常温常压下 ,在 5 0 0 0t a工业化装置中 ,生产符合国标ZBG2 10 0 6 89农用一级品硫酸钾。整个过程流程较简单 ,能耗低 ,投资省 ,基本无“三废”排放。钾的收率达70 %。工艺条件稳定 ,产品质量稳定。中试结果与小试有较好的重复性 ,放大效果好。     

散装液体危化品码头的污染原因分析及防控对策

介绍了液体危化品的特点,对散装液体危化品码头的污染原因进行了分析,并提出了相应的防控对策,为确保码头安全稳定运行提供了保障.