催化分解法处理臭氧尾气的研究

以活性炭和γ -Al2 O3 为载体制备出负载锰和铜氧化物的用于臭氧尾气处理的催化剂 ,并采用固定床反应器进行分解臭氧尾气的实验研究。实验结果表明 ,活性炭负载锰和铜氧化物的催化剂的性能最好 ,1g催化剂在臭氧初始浓度为2 .5 g/m3 ,反应时间为 0 .0 36s条件下 ,其对臭氧的分解率可达 97.2 %。在相同臭氧初始浓度 ,反应时间为 0 .1s条件下 ,1g催化剂可以连续运转达 98h ,处理臭氧总量为 8.8g ,且湿度对其催化活性影响较大。     

废乳化液处理工艺的研究和应用

采用无动力油水分离器除浮油—破乳气浮—过滤、吸附工艺处理废乳化液 ,取得 COD去除率 99.88% ,实现p H6～ 9,COD<5 0 0 / mg·L- 1排放要求 ,运行效果稳定可靠。     

Integral Model for Turbulent Buoyant Jets in Unbounded Stratified Flows Part 2: Plane Jet Dynamics Resulting from Multiport Diffuser Jets

An integral model for the plane buoyant jet dynamics resulting from the interaction of multiple buoyant jet effluxes spaced along a diffuser line is considered as an extension of the round jet formulation that was proposed in Part I. The receiving fluid is given by an unbounded ambient environment with uniform density or stable density stratification and under stagnant or steady sheared current conditions. Applications for this situation are primarily for submerged multiport diffusers for discharges of liquid effluents into ambient water bodies, but also for multiple cooling tower plumes and building air-conditioning. The CorJet model formulation describes the conservation of mass, momentum, buoyancy and scalar quantities in the turbulent jet flow in the plane jet geometry. It employs an entrainment closure approach that distinguishes between the separate contributions of transverse shear and of internal instability mechanisms, and contains a quadratic law turbulent pressure force mechanism. But the model formulation also includes several significant three-dimensional effects that distinguish actual diffuser installations in the water environment. These relate to local merging processes from the individual multiple jets, to overall finite length effects affecting the plume geometry, and to bottom proximity effects given by a “leakage factor” that measures the combined affect of port height and spacing in allowing the ambient flow to pass through the diffuser line in order to provide sufficient entrainment flow for the mixing downstream from the diffuser. The model is validated in several stages: First, comparison with experimental data for the asymptotic, self-similar stages of plane buoyant jet flows, i.e. the plane pure jet, the pure plume, the pure wake, the advected line puff, and the advected line thermal, support the choice of the turbulent closure coefficients contained in the entrainment formulation. Second, comparison with data for many types of non-equilibrium flows with a plane geometry support the proposed functional form of the entrainment relationship, and also the role of the pressure force in the jet deflection dynamics. Third, the observed behavior of the merging process from different types of multiport diffuser discharges in both stagnant and flowing ambient conditions and with stratification appears well predicted with the CorJet formulation. Fourth, a number of spatial limits of applicability, relating to terminal layer formation in stratification or transition to passive diffusion in a turbulent ambient shear flow, have been proposed. In sum, the CorJet integral model appears to provide a mechanistically sound, accurate and reliable representation of complex buoyant jet mixing processes, provided the condition of an unbounded receiving fluid is satisfied.     

Diapycnal Mixing in the Thermocline of Lakes: Estimations by Different Methods

In order to evaluate the performance of different methods for estimation of the vertical eddy diffusivity in thermally stratified lakes, two field studies were conducted in Lake Biwa, Japan and Lake Kinneret, Israel. Lake Biwa experienced three typhoons during the campaign while Lake Kinneret experienced high winds in the afternoons. Microstructure profiles were collected by a portable flux profiler (PFP) during calm and disturbed periods. Then, the vertical eddy diffusivity was estimated by three indirect methods. The estimated vertical eddy diffusivities varied more than one order of magnitude, from 4.7× 10⁻⁷ to 7.7× 10⁻⁶ m² s⁻¹. The comparison of results with previous buoyancy flux measurements and scaling arguments showed that the Dillon–Park’s method is not appropriate and Osborn–Cox method performs better than Osborn method in the studied case. Furthermore, the low value of vertical eddy diffusivity within the thermocline suggests that within the thermocline of these lakes, diffusive vertical transport can be neglected.     

Environmental Impact of Undular Tidal Bores in Tropical Rivers

A tidal bore impacts significantly on the estuarine ecosystem, although little is known on the flow field, mixing and sediment motion beneath tidal bores. In the absence of detailed systematic field measurements, a quasi-steady flow analogy was applied to investigate undular tidal bores with inflow Froude numbers between 1.25 and 1.6. Experimental results indicated that rapid flow redistributions occur beneath the free-surface undulations, with significant variations in bed shear stress between wave crests and troughs. Dynamic similarity was used to predict detailed flow characteristics of undular tidal bores. The effects of periodic loading on river sediments, scour of river bed and flow mixing behind the bore are discussed. A better understanding of these processes will contribute to better management practices in tidal bore affected rivers, including the Styx and Daly rivers in tropical Australia.     

Advanced process systems design technology for pollution prevention and waste treatment

The paper presents a generic process synthesis and optimisation tool suitable to take up applications in the design of waste treatment systems and in pollution prevention. The main component of the technology is a generalized process synthesis representation for simultaneous consideration of reaction and separation in multiphase systems that is amenable for stochastic optimisation. The flexibility of the representation allows applications to overall process synthesis problems as well as to decomposed reactor, reactive separation and mass exchange network design problems. Applications of the synthesis framework to waste water treatments processes using activated sludge and to natural gas sweetening in hybrid membrane-adsorption processes are presented. The paper highlights the use of the systematic technology in environmental systems design and shows how novel designs of improved performance as well as optimal design knowledge can be revealed using the systematic design framework. Context abstract: Environmental process systems for waste treatment and pollution prevention become increasingly complicated to design. There is a strong need for technology that provides systematic decision support to the process synthesis team in order to enable the timely selection of processes that operate close to the performance limits of the system under consideration. Conventional, optimisation-based process design technology is severely limited by the number of design decisions they can support simultaneously as well as by the increasingly complex process models required for the meaningful mathematical representation of environmental process systems. We have devised an optimisation-based process design methodology for integrated reaction and separation systems that overcomes major limitations of existing tools. This paper illustrates the use of this technology to provide systematic decision-support to the environmental process systems designer.     

装饰材料所致的室内空气污染

对商业、工业、住宅等不同功能区和不同室内燃料的厨房、卧室、教室等室内房间，作了空气中甲醛的本底值调查。调查表明，甲醛浓度范围为０．０００７－０．０１２５ｍｇ／ｍ＾３。对１５户普通家庭装潢户的调查表明，经装潢后１年以上测得的甲醛，总烃、苯、甲苯平均浓度分别为０．０２、０．５０、０．７６、１．２５ｍｇ／ｍ＾３。氯乙烯、苯乙烯未测出。其中甲醛平均浓度高出本底值２０倍，为前苏联建议的日平均浓度的１．６倍。     

环境空气中二氧化氮的测定及问题研究

通过介绍环境空气中二氧化氮的测定方法──自动仪器监测法，对有关问题进行了初步探讨和研究，为正确使用该方法和仪器，确保监测工作的顺利进行提供了依据。     

作业环境空气中醋酸异丁酯的气相色谱测定方法

根据国外卫生标准的要求，建立了作业环境空气中醋酸异丁酯的气相色谱分析测定方法．     

Landfill gas - a potential environmental hazard

Methane derived from the decomposition of organic material contained within a landfill may escape beyond the site boundary where it can pose an explosion or fire hazard. Methods are described to prevent die occurrence of such lateral gas migration. Problems due to the accumulation of gas in buildings, erected on landfill sites, have occurred and techniques are now available to overcome these at some sites. However, it is recognized that at other sites, redevelopment should not be allowed to take place on die grounds of safety.