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1.
2.
Comparative gas cleaning performance of a pilot-scale venturi scrubber with throat dimensions of 6 in. wide × 1 2 in. long × 1 2 in. deep was obtained for the following three methods of water injection: a system of spray nozzles located along each short side of the throat (Figure 2a); a continuous slot located immediately above the nozzles, along each short side of the throat (Figure 2b); and a weir located 2 ft above the spray nozzles along long side of the throat (Figure 2c). For each method of water injection the gas cleaning performance, as a function of the pressure drop, was measured by two tests: absorption of SO2 and collection efficiency for particles of methylene blue of controlled size.  相似文献   

3.
In January 1966, 483 randomly selected 1963-1966-model automobiles were inspected at the Cincinnati Vehicle Inspection Station to determine the effectiveness of their positive crankcase ventilation systems. All of these automobiles should have had crankcase ventilation systems installed in accord with the voluntary program of the automobile manufacturers. However, 48 of the automobiles inspected had no positive crankcase ventilation system. In addition, 27 cars were equipped with systems which could not readily be tested. Testing of the remaining 408 cars was performed with a combination pressure-vacuum gauge designed to measure the airflow in the crankcase. Results showed that 71% of the positive crankcase ventilation systems tested were operating satisfactorily and impending maintenance of systems was indicated for 29% of the automobiles tested. Although the systems of certain makes of cars performed considerably better than others, a definite decrease in system performance with increasing age and mileage was observed for the cars tested. The performance data indicate that the periodic maintenance required for positive crankcase ventilation systems is not being implemented. Only 47.5% of the drivers questioned were aware of the system and only 10% knew whether their system had been serviced.  相似文献   

4.
A survey of academic programs in air pollution control was made. Results from the 127 schools reporting are tabulated by state. Faculty involved in air pollution instruction are identified. Some conclusions and recommendations are presented.  相似文献   

5.
The body of information presented in this paper is directed towards engineers in the field of environmental sciences involved in measuring and/or evaluating the emissions from a variety of diesel engines or vehicles. This paper summarizes recent data obtained by EPA on identification and quantification of different emissions (i.e. characterization) from a variety of diesel engines.

Extensive work has been done comparing emissions from some light duty diesel and gasoline passenger cars. The work on the diesel vehicles was expanded to include tests with five different diesel fuels to determine how fuel composition affects emissions. This work showed that use of a poorer quality fuel frequently made emissions worse. The investigation of fuel composition continued with a project in which specific fuel parameters were systematically varied to determine their effect on emissions. EPA is presently testing a variety of fuels derived from coal and oil shale to determine their effects on emissions.

EPA has also tested a heavy duty Volvo diesel bus engine designed to run on methanol and diesel fuel, each injected through its own injection system. The use of the dual fuel resulted in a reduction in particulates and NO x but an increase in HC and CO compared to a baseline Volvo diesel engine running on pure diesel fuel.

Finally, some Ames bioassay tests have been performed on samples from the diesel passenger cars operated on various fuels and blends. An increase in Ames test response (mutagenicity) was seen when the higher aromatic blend was used and also when a commercial cetane improver was used. Samples from the Volvo diesel bus engine fueled with methanol and diesel fuel showed that use of a catalyst increased the Ames response.  相似文献   

6.
Abstract

In this study, the effects of the basicity on the pouring point of the municipal solid waste incinerator fly ash-sewage sludge ash mixture is investigated. Four kinds of sewage sludge ash, which were collected from several primary and secondary sewage treatment plants and were produced by different processes and sludge conditioning alternatives, were used as modifiers. The results indicate that the pouring point of the mixture increased with increasing basicity, within the range of 0.65–1.90. The pouring point is affected by the contents of the mixtures (CaO, SiO2, Al2O3, and the flux). It is suggested that an increase in the CaO content tends to raise the pouring point, whereas an increase in the SiO2 and/or the Al2O3 contents cause as adverse reaction. The prediction equation, obtained by multilinear regression (significant level is 0.05), is as follows: pouring temperature =1189.6 + 4.19CaO-0.96 SiO2-4.33 Al2O3 (R2 = 0.91). In general, the pouring point decreased when the basicity was <1. The pouring point apparently increased when the basicity was>1.2. The regression squares for the different basicities were between 0.84 and 0.91. From these relationships, we note that a basicity index of 5 gave the best R2 (0.91). From the results of this study, it can be concluded that the modification of the basicity of the fly ash by the addition of sewage sludge ash to lower the pouring point is feasible and leads to a more energy-efficient melting process. In addition, these synthetic slags have a good pozzolanic reactive activity.  相似文献   

7.
The various uses of fire in agricultural practice are discussed in a framework of three general purposes: (1) waste disposal, {2) disease control, and (3) land and crop management.In each purpose the use of fire or burning is discussed in relation to the general requirements and to the problems of air pollution control.  相似文献   

8.
文中详述了焚烧炉中二恶英废气产生的原因,针对产生原因提出控制方法,并总结出治理二恶英废气的措施。提出了今后对二恶英的控制建议。  相似文献   

9.
10.
针对印染企业集中园区产生的综合废水复杂多变,必要选择合式的处理工艺,因此,以某印染企业集中园区的污水处理厂为例,采用厌氧+好氧+物化组合工艺,并对废水的脱色和可生化性的改善进行了试验研究,通过类比调查,优化工程设计参数;经工程实践证明,综合印染废水经该工艺处理后,能达到一级排放标准.  相似文献   

11.
Abstract

This paper presents a comparative assessment of the cost and quality of treatment of tannery wastewater in India by two common effluent treatment plants (CETPs) constructed for two tannery clusters, at Jajmau (Kanpur) and at Unnao in the state of Uttar Pradesh, India. The Jajmau plant is upflow anaerobic sludge blanket (UASB) process-based, while the Unnao plant is activated sludge process (ASP)-based. Investigations indicated that the ASP-based plant was superior in all respects. Total annualized costs, including capital and operation and maintenance costs, for the UASB and ASP plants were Rs. 4.24 million/million liters per day (MLD) and Rs. 3.36 million/MLD, respectively. Land requirements for the two CETPs were 1.4 hectares/MLD and 0.95 hectares/MLD, respectively. Moreover, the treated UASB effluent had higher biochemical and chemical oxygen demand (BOD/COD) and considerable amounts of other undesirable constituents, like chromium (Cr) and sulfide, as compared with the ASP effluent, which had lower BOD/COD and negligible concentration of sulfide and Cr. Sludge production from the UASB-based plant was also higher at 1.4 t/day/MLD, in comparison to the sludge production of 0.8 t/day/MLD for the ASP-based plant. Also, the entire sludge produced in the UASB-based plant was Cr-contaminated and, hence, hazardous, while only a small fraction of the sludge produced in the ASP-based plant was similarly contaminated. The results of this study are at variance with the conventional wisdom of the superiority of anaerobic processes for tannery waste-water treatment in tropical developing countries like India.  相似文献   

12.
13.
Abstract

The incineration of solid waste produces large quantities of bottom and fly ash. Landfilling has been the primary mode of disposal of these waste materials. Shortage in landfill space and the high cost of treatment have, however, prompted the search for alternative uses of these waste materials. This study presents an experimental program that was conducted to determine the engineering properties of incinerator ash mixes for use as construction materials. Incinerator ash mixes were tested as received and around optimum compacted conditions. Compaction curves, shear strength, and permeability values of fly ash, bottom ash, and their various blends were investigated. Bottom ash tends to achieve maximum dry density at much lower water content than does fly ash. The mixes displayed a change in their cohesion and friction angle values when one of the two mix components was altered or as a result of the addition of water. The permeability of bottom ash is quite comparable to that of sand. The permeability of fly ash lies in the range of those values obtained for silts and clays. A 100% bottom ash compacted at the optimum water content has a lower density value and yields a higher friction angle and cohesion values than most construction fills. This would encourage the use of bottom ash as a fill or embankment material because free drainage of water will prevent the buildup of pore water pressures.  相似文献   

14.
A high-temperature, slagging rotary kiln hazardous waste incineration system with modern combustion, heat recovery and air pollution control equipment was put in operation at PPG Coating and Resin Plant in Circleville, Ohio in the latter part of 1987. New design solutions contributed to the overall high performance of the system. The system employs European and American feed, combustion, heat recovery and stack emission control technologies. Performance of the system is analyzed in detail covering topics such as feed methods, equipment selection, destruction and removal efficiencies, fate of the metals, and financial information.  相似文献   

15.
Two directionally oriented high-volume samplers are used to pinpoint the collection of specific inorganic dusts from an industrial emission. One of the samplers is placed upwind of the source, and the other downwind. Both samplers are activated by winds blowing from the direction of the source to the downwind sampler. Both are de-activated when the wind shifts from the 30° sampling arc. Thus, the upwind sampler “sees” background dust, and the downwind sampler “sees” material originating from the source. Microsorban filters are used to collect the dust materials. The filter is then dissolved in benzene and the residue washed with benzene to remove the filter material and organic substances collected. The residue consists of dry, inorganic dust, which is then subjected to X-ray diffraction and optical microscopy, for analysis. This technique was successfully used to collect and analyze cement dust and mica dust from two separate industrial sources. The technique has promise for the analysis of a wide variety of inorganic materials which can be identified by X-ray diffraction, optical microscopy or other techniques.  相似文献   

16.
叙述了420 kg/h医疗废弃物焚烧处理技术 设备的特点以及应用。  相似文献   

17.
ABSTRACT

The introduction of reformulated gasolines significantly reduced exhaust hydrocarbon (HC) mass emissions, but few data are available concerning how these new fuels affect exhaust reactivity. Similarly, while it is well established that high-emitting vehicles contribute a significant portion of total mobile source HC mass emissions, it is also important to evaluate the exhaust reactivity from these vehicles. The objective of this study was to evaluate the relative influence on in-use vehicle exhaust reactivity of three critical factors: fuel, driving cycle, and vehicle emission status. Nineteen in-use vehicles were tested with seven randomly assigned fuel types and two driving cycles: the Federal Test Procedure (FTP) and the Unified Cycle (UC). Total exhaust reactivity was not statistically different between the FTP and UC cycles but was significantly affected by fuel type. On average, the exhaust reactivity for California Phase 2 fuel was the lowest (16 % below the highest fuel type) among the seven fuels tested for cold start emissions. The average exhaust reactivity for high-emitting vehicles was significantly higher for hot stabilized (11%) and hot start (15%) emissions than for low-emitting vehicles. The exhaust reactivities for the FTP and UC cycles for light-end HCs and carbonyls were significantly different for the hot stabilized mode. There was a significant fuel effect on the mean specific reactivity (SR) for the mid-range HCs, but not for light-end HCs or carbonyls, while vehicle emission status affected the mean SR for all three HC compound classes.  相似文献   

18.
19.
Abstract

An assessment of the short- and long-term hazards from municipal solid waste incinerator (MSWI) ash is made through the elemental analysis of 40 to 50 elements in the ash and leachates produced by several leaching procedures. The ash was analyzed using neutron activation analysis (NAA) and x-ray fluorescence (XRF). The leachates were analyzed using NAA and inductively-coupled plasma atomic emission spectroscopy (ICP). The leaching dynamics of an ash monofill were modelled with a series of extractions using simulated acid rain. An initial spike of the metals Ag, Ba, Be, Cr, Cu, Mo, Pb, Sr, and Zn in the leachates appears to be the greatest hazard posed by MSWI ash monofills. The elements As, Cd, Cu, Hg, Pb, S, and Zn were identified as potential long term hazards utilizing a sequential extraction procedure which approximates the total amount of the elements available over the lifetime of the monofill.

The pH of the resulting leachate is the single greatest factor governing the concentration of metals in solution, more important than the concentration of the element in the ash. These results are applied to an assessment of the suitability of the Toxicity Characteristic Leaching Procedure (TCLP) in measuring leaching potential of an MSWI ash monofill.  相似文献   

20.
A test program for the Shirco infrared destruction process is described in this article. This incineration process is transportable and can be an effective method for cleanup of soils from Superfund sites. A pilot-scale unit and a 100-ton per day transportable unit were tested as part of the Superfund Technology Evaluation (SITE) program.

The process consists of a thermal destruction chamber where electricity is used for infrared rods that heat the waste, and a second chamber where propane is used to destroy any remaining hydrocarbons in the exhaust from the first chamber. A venturi scrubber and horizontal packed tower were used for particulate removal before exhausting the gas to the atmosphere. The feed material was reduced to less than one inch in diameter before it was processed by the unit.

The testing indicated that the Shirco system would remove and destroy organics from a waste, but would not remove heavy metals. The scrubber on the full scale system was of marginal capacity for that particular application and did not meet the RCRA specifications of 180 mg/dscm during two of the four tests made for the full scale unit.

Both units achieved Destruction and Removal Efficiencies (DRE) in excess of the 99.99 percent required for RCRA applications. Performance with respect to the TSCA requirement of 99.9999 percent for PCBs could not be ascertained due to the concentration of PCB in the feed.  相似文献   

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