4th International Clean Air Congress May 16 ∼ 20, 1977 Tokyo

The ways in which anhydrous ammonia may accidentally escape to the atmosphere from refrigerated or pressurized containment are systematically reviewed. The circumstances in which the ammonia may form part of a mixture which is buoyant, neutrally buoyant, or denser than air are described and for each mode of release there is a discussion of the likely density of the resulting ammonia cloud.     

Nomograph for Field Checking Meter Calibrations on EPA-Type Stack Sampling Trains

In a typical "EPA train" for stack sampling, there are two meters, the dry gas meter and the orifice meter, which require periodic calibration. The controversy which presently exists over the required frequency of calibration is the result of using meters which rarely need calibration, but which have the potential of changing calibration at any time.     

Assessing the environmental fate of chemicals of emerging concern: a case study of the polybrominated diphenyl ethers

It is suggested that assessments of chemicals of emerging concern can be rationally structured around a multistage process in which fate and risk are evaluated with increasing accuracy as new data become available. An initial tentative and approximate assessment of fate and risk can identify key data gaps and justify and direct further investigations, which progressively improve the reliability of the assessment. This approach is demonstrated for a class of chemicals, the polybrominated diphenyl ethers (PBDEs), which is of increasing concern, but about which there is presently a lack of comprehensive data on properties, sources, fate and effects. Specifically, 20 PBDE congeners are investigated using the suggested approach and research needs are identified.     

Chemistry of Atmospheric Oxidants

All of the important oxidants in polluted air are formed there by chemical reactions which occur among the primary pollutants. The most abundant of these oxidants is ozone which is formed in a cycle involving nitric oxide, nitrogen dioxide, atmospheric oxygen, and hydrocarbons. This ozone is best understood, not as a reaction product, but as an intermediate in steady-state concentration between formation and disappearance reactions. Hydrocarbons permit accumulation of ozone by reacting to scavenge the nitric oxide which would otherwise remove the ozone. The amount of ozone which can be formed in ambient polluted air is limited to about 1 ppm because these scavenging reactions become less effective when the nitric oxide concentration becomes very small. The peroxyacyl nitrates are a group of oxidants which result from reactions between oxides of nitrogen and organic pollutants. Olefinic and aromatic hydrocarbons make the largest contribution to PAN formation; saturates contribute little if any. The role of nitrogen dioxide and other oxidizing agents is also discussed.     

Analysis of field observations of tracer transport in a fractured till

We analyze a set of observations from a recently published, field-scale tracer test in a fractured till. These observations demonstrate a dominant, underlying non-Fickian behavior, which cannot be quantified using traditional modeling approaches. We use a continuous time random walk (CTRW) approach which thoroughly accounts for the measurements, and which is based on a physical picture of contaminant motion that is consistent with the geometric and hydraulic characterization of the fractured formation. We also incorporate convolution techniques in the CTRW theory, to consider transport between different regions containing distinct heterogeneity patterns. These results enhance the possibility that limitations in predicting non-Fickian modes of contaminant migration can be overcome.     

Electrolytic treatment of an industrial wastewater from a hosiery plant.

Textile plant wastewater being treated in a facultative pond system had too high of a solids concentration to be reused in the dying and rinsing processes. Electrocoagulation was evaluated to further treat the pond effluent to remove turbidity, which was caused by dyes and microorganisms. A range of amperages were tested for removal of turbidity and chemical oxygen demand (COD). Electrocoagulation lowered the turbidity from 1400 NTU to below 50 NTU; and COD was lowered from 550 mg/L to approximately 250 mg/L, which was acceptable for reuse. In addition, a laboratory-scale sedimentation study was conducted on the electrocoagulated pond effluent, which indicated that a settling time of 35 minutes would provide for 80% removal of suspended solids, which was acceptable for reuse of the water in plant processes.     

巢湖合肥地区洗衣粉排磷占入湖磷贡献率的研究

合肥地区人均洗衣粉用量为3．12kg/a,洗衣粉总用量为8345t/a,洗衣粉带入水体的总磷量为256．08t/a,占入湖总磷负荷量的13．62％。因此,实行“禁磷”措施后,可削减该地区入湖总磷负荷量的13．62％,对改善巢湖水质将会起到一定的积极作用。     

Epidemiological Aspects of Air Pollution

An urban air pollution incident, like a natural or man-made catastrophe, presents a crisis situation which can only be relieved if adequate contingency plans have been prepared in advance and an effective control organization is in a state of operational readiness to meet the threatened emergency. Although many air pollution incident control plans have been proposed in the past, most have remained in the conceptual or theoretical stages of preparation, because the relative infrequency of serious urban air pollution crises and the disruptive nature of major emission control operations tend to limit the opportunities available for field testing of these plans. In this respect, air pollution incident control planning is analogous to strategic planning for a military operation, where the only completely legitimate test of a strategy is applied on the battlefield. In order to accomplish the transition from conceptual planning to a practical, operational field strategy for air pollution incident control, a program of incident control tests has been initiated in Chicago. These field tests, which use the city as a laboratory for the development of control strategies, are analogous to a series of military war games in which communication systems, command and control organizational structures, personnel roles, surveillance and monitoring equipment, control resources and pollution source controllability are tested under conditions which approximate as closely as possible the situation which prevails during an actual air pollution incident. This paper discusses the evolution of an incident control strategy from an initial, fixed response emission control exercise, through a meteorologically initiated control test to a fairly realistic war game series which is still developing.     

Organizational and Operational Techniques for Relieving Manpower Shortages in Air Pollution Control Agencies

Many governmental air pollution control agencies are confronted with a shortage of manpower, both in terms of numbers of people and qualifications of available staff members. This paper discusses a number of techniques which may be used to relieve this manpower shortage. The techniques are discussed in terms of collaboration between state and local agencies; organizational structures which make maximum use of scarce categories of people; program policies which conserve the time of agency staff; operating schemes which save travel time and minimize skills required; and working tools that can be used to get the greatest production with available personnel.     

Reduction of nitrogen excretion and emission in poultry: A review for organic poultry

Organic poultry is an alternative to conventional poultry which is rapidly developing as a response to customers' demand for better food and a cleaner environment. Although organic poultry manure can partially be utilized by organic horticultural producers, litter accumulation as well as excessive nitrogen still remains a challenge to maintain environment pureness, animal, and human health. Compared to conventional poultry, diet formulation without nitrogen overloading in organic poultry is even more complicated due to specific standards and regulations which limit the application of some supplements and imposes specific criteria to the ingredients in use. This is especially valid for methionine provision which supplementation as a crystalline form is only temporarily allowed. This review is focused on the utilization of various protein sources in the preparation of a diet composed of 100% organic ingredients which meet the avian physiology need for methionine, while avoiding protein overload. The potential to use unconventional protein sources such as invertebrates and microbial proteins to achieve optimal amino acid provision is also discussed.     

A spatially-evaluated methodology for assessing risk to a population from contaminated land

A methodology is proposed which combines quantitative probabilistic human health risk assessment and spatial statistical methods (geostatistics) to produce an assessment of risks to human health from exposure to contaminated land, in a manner which preserves the spatial distribution of risks and provides a measure of uncertainty in the assessment. Maps of soil contaminant levels, which incorporate uncertainty, are produced from sparse sample data using sequential indicator simulation. A real, age-stratified population is mapped across the contaminated area, and intake of soil contaminants by individuals is calculated probabilistically using an adaptation of the Contaminated Land Exposure Assessment (CLEA) model. An abundance of information is contained in results which can be interrogated at the population and individual level, and mapped to provide a powerful visual tool for risk managers, enabling efficient targeting of risk reduction measures to different locations.     

Improving Plume Rise Prediction Accuracy for Stable Atmospheres with Complex Vertical Structure

Accurately predicting the rise of a buoyant exhaust plume is difficult when there are large vertical variations in atmospheric stability or wind velocity. Such conditions are particularly common near shoreline power plants. Simple plume rise formulas, which employ only a mean temperature gradient and a mean wind speed, cannot be expected to adequately treat an atmosphere whose lapse rate and wind velocity vary markedly with height. This paper tests the accuracy of a plume rise model which is capable of treating complex atmospheric structure because it integrates along the plume trajectory. The model consists of a set of ordinary differential equations, derived from the fluid equations of motion, with an entralnment parameterization to specify the mixing of ambient air into the plume. Comparing model predictions of final plume rise to field observations yields a root mean square difference of 24 m, which is 9 % of the average plume rise of 267 m. These predictions are more accurate than predictions given by three simpler models which utilize variants of a standard plume rise formula, the most accurate of the simpler models having a 12% error.     

Fugacity models of indoor exposure to volatile chemicals

A method of calculating the atmospheric concentration of a volatile chemical in confined volumes is presented and illustrated which uses the fugacity concept to simplify the manipulation of the various transport and reaction terms. The method is particularly suitable for estimating exposure to chemicals which may be released by evaporation into a house, work place, or partially confined outdoor environment in which there are several volumes (eg. rooms) with known ventilation characteristics. Illustrative calculations are presented.     

a rapid emission survey procedure for industrial air pollutants

A methodology has been developed to calculate industrial air pollutant emissions with an absolute minimum of effort. The procedure is dependent upon available industrial fuel data for Standard Industrial Classifications for Standard Metropolitan Statistical Areas as published by the Census of Manufacturers. Emission factors were developed which include both combustion and process losses and six SIC classifications which consume, on the average, about 80 per cent of the industrial fuels in urban areas. In spite of the diversity of industrial processes which dictate the weight of emissions discharged from industrial operation, factors have been developed which are considered representative for urban areas across the nation. The development of such factors permits the calculation of industrial emissions with a minimum of man-hours. The developed procedure allows the calculation of industrial emissions on an urban basis, a state basis, or a nation basis.     

铬离子对SBR工艺活性污泥毒性作用研究

针对重金属铬离子对SBR工艺系统中活性污泥的毒性作用,通过检测不同初始污泥容积指数(SVI)下SBR工艺活性污泥在不同铬负荷下的COD值、挥发性污泥浓度以及受铬离子影响的污泥容积指数(SVI),研究重金属铬离子对活性污泥的毒性作用以及对SBR工艺系统处理污水的影响。研究表明,重金属铬离子会导致SBR工艺系统出水COD升高;将铬离子对活性污泥的毒性作用按照挥发性污泥(MLVSS)铬负荷可划分为耐受范围、非耐受范围、细胞失活范围以及细胞分解范围。耐受范围铬负荷低于约30 mg Cr3+/gMLVSS,此范围内铬离子对于活性污泥的毒性作用不大,不致于导致系统出水水质变差;非耐受范围铬负荷在约30~65 mg Cr3+/g MLVSS,在铬离子作用下系统出水COD值明显高于对照系统;细胞失活范围铬负荷在约70~100 mg Cr3+/gMLVSS范围内,SVI大幅下降,微生物部份死亡和失活,出水COD尽管有一些下降,但与进水COD相比差不了多少;细胞分解范围铬负荷在约100 mg Cr3+/gMLVSS以上,微生物大量死亡,部分死亡细胞分解,系统出水COD值因微生物的死亡分解而超出进水COD值,受铬离子影响的系统SVI值大幅度降低。     

Long-term scenarios for surface transport

Current trends in transport indicate that the system is moving away from a sustainable development (e.g., due to rising CO₂ emissions), and that major changes in technology and public policy, as well as in the behaviour of individuals, are necessary to make the transport system more compatible with environmental sustainability. This indicates the need to assess a set of future images for transport in relation to the environment. In this paper, reference and expert scenarios, which can act as a judgement framework for a sustainable transport system, are constructed on the basis of the recently developed 'spider model'. Based on a set of distinct characteristics of a transport system, represented by eight axes in the spatial, institutional, economic and social psychological field, an evaluation framework is constructed, which visualises the driving forces that largely influence the future of the transport system. There are several directions in which these factors may develop, and each of them will separately or in combination lead to entirely different transport systems. In this way, many scenarios can be constructed by connecting points on the successive axes. Such scenarios may range from market-oriented to regulatory pictures; the first may lead to a transport system in which individual, the second in which collective modes of transport dominate. Next, expected and desired scenarios are constructed from the opinions of Dutch transport experts, who responded to a nationwide survey. The expected scenario indicates that many current trends will continue, while the transport system is largely the same as the current one. The desired scenario, on the other hand, gives a more collective system, in which also many new modes are operating. The conclusion is that there are many roads for achieving a sustainable transport system, but that whichever one is chosen, it will be hard to follow.     

Supporting the development of environmentally sustainable technologies and products: the role of innovation, informal cooperation and governmental agency

Sustainable, economic, environmental and social development will require substantial improvements in the efficiency of present environmental and resource use, which in turn will increase the focus on a broader set of environmental, economic and social linkages. These are the result of dynamic interactions, in which changes in one set of factors will impact on others, and vice versa. This paper discusses the role and potential of technology, innovation and interorganisational collaboration as strategic drivers of a renewed market-driven green development in industry, and it discusses the ways in which governments have and can nurture and support an environmentally more sustainable development.     

An Inexpensive Remote Sequential Air Sampler

A remote sequential air sampling unit has been developed which is compact, lightweight, and quite inexpensive. The sampling device contains a number of spring-loaded syringes which are released sequentially by the motion of a rotary mechanical timer. Field tests indicate that the sampling device can take accurate sequential air samples automatically and contain each sample without leakage for at least a period of 18 hours in an outdoor environment.     

铁黄生产中废水处理与废渣的回收利用

介绍了氧化铁黄生产中的废水治理情况，同时其产生的废渣可回收利用。经过治理产生的环境、经济和社会效益显著。     

Effects of pH and feeding regime on methylmercury accumulation within aquatic microcosms

The effect of pH (pH 5, 6 or 7) on accumulation of radiolabelled methylmercury was examined using a laboratory microcosm system. Accumulation of labelled mercury at three trophic levels, primary consumers (Daphnia magna), secondary consumers (rainbow trout, Salmo gairdneri) and tertiary consumers (walleye, Stizostedion vitreum) was not significantly affected by pH. Our results are in direct contrast with field observations of elevated methylmercury concentrations in fish from low pH water and indicate that the elevated mercury residues observed in the field result from factors other than the direct effects of pH on accumulation of methylmercury by aquatic organisms. Both water and diet were important as sources of the labelled mercury which was accumulated by walleye. Walleye which were fed rainbow trout, that had accumulated labelled mercury from within the experimental microcosms, accumulated almost twice as much labelled mercury as walleye fed non-labelled prey, or walleye which were not fed. Walleye fed non-labelled rainbow trout accumulated slightly more labelled mercury than walleye which were not fed, presumably as a result of the higher metabolic rate of the fish which were fed.