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991.
992.
This is the fourth in the series of Critical Reviews commissioned by the APCA Board of Directors. The first Critical Review "Regulations for the Control of Particulate and Sulfur Oxides Emissions" was published in 1974 and the topic is still timely. The second Critical Review "Regulations for the Control of Hydrocarbon Emissions (from Stationary Sources) and Odorous Pollutants" was published in 1975. In light of recent developments concerning hydrocarbon emissions from stationary sources, this Critical Review is again very timely. The third Critical Review "The Effect of Air Pollution Control Regulations on Land Use Planning" will soon be published in final form. Now we have the fourth in the series, "A Critical Review of Air Pollution Index Systems in the United States and Canada" and "Status Report on Federal Regulations for New Source Performance Standards". 相似文献
993.
反渗透处理稀土氨氮废水试验研究 总被引:4,自引:2,他引:2
根据稀土冶炼厂排放的碳铵沉淀洗涤废水的水质情况,采用NH4Cl和 NaCl模拟废水进行了反渗透可行性对比实验。模拟实验发现,在相同条件下反渗透对NaCl 较NH4Cl 有着更高的去除率,而NH4Cl 相对NaCl则有着更高的产水速率。实际废水试验结果表明,在恒定操作压力范围内回收率为65%的条件下,NH4Cl浓度为2.85 g/L的碳铵沉淀洗涤废水经反渗透处理其NH4Cl去除率为77.3%,可作为氨氮废水的预处理。对该废水处理成本进行了分析,得出其约为2.7元/m3,比相近浓度氨氮废水的氨吹脱处理成本节省约26%。 相似文献
994.
J. M. Genco H. S. Rosenberg M. Y. Anastas E. C. Rosar J. M. Dulin 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1244-1253
This paper describes some technical and economic aspects of the nahcolite ore injection process for the simultaneous removal of fly ash and sulfur oxides from stack gases. The process is capable of removing greater than 99% of the particulate matter and greater than 70% of the sulfur oxides present in such gases. In the process, nahcolite ore, a naturally occurring material containing 70 to 90% sodium bicarbonate, is ground to 90% passing through —200 mesh screens. Approximately 20% of the ground ore is used to precoat the filter bags in a baghouse filter while the remainder of the material is fed into the flue gas Just ahead of the baghouse. The flue gas is drawn through the baghouse by induced draft fans and sent up the stack. Most of the SO2 and practically all of the fly ash in the flue gas can be removed as the gas passes through the filter bags. The spent nahcolite ore and fly ash are collected and conveyed to waste disposal as landfill, or alternatively processed for insolubilization by coprecipitation prior to landfilling. The technical feasibility of the process has been demonstrated in both bench scale and pilot scale engineering studies. Economic analyses performed for the cases of plants located in the midwest and southwest indicate lower capital costs for the nahcolite injection process when compared to wet scrubbing. On an annual cost basis, the nahcolite ore Injection process is comparable in cost to wet scrubbing for the case of the southwestern power plant, and somewhat more expensive for the case of the midwestern plant. 相似文献
995.
Earl H. Markee Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(3):118-120
Changes in contaminant levels at monitoring stations do not necessarily represent changes in emission levels, since variations in meteorological parameters determine the transport and diffusion of contaminants between sources and receptors. To estimate annual changes in emission levels, and thus of control program effectiveness, the meteorological stratification of data was employed to provide “comparable days.” For San Francisco Bay Area photochemical oxidant data, simple criteria based on maximum temperature and on height of inversion base were selected. Temperature provided a readily available integrated index of solar energy input and of ventilation, while the inversion data added a vertical dilution factor. An earlier study, employing only the temperature criteria, showed that oxidant levels on comparable warm days had nearly doubled from 1954 through 1962. The current study of oxidant data for 1962 through 1969 shows a gradual rise through 1965, and a sharp reversal in 1966, when for the first time a simultaneous decrease was noted at each benchmark station. Data through 1969 show that average oxidant levels have been maintained at this 25% lower plateau, with minor fluctuations at individual stations. The general improvement in air quality since 1965 is attributed to the reduction of reactive organics emitted from stationary and automotive sources. 相似文献
996.
F. Boukhoubza A. Jail F. Korchi L. Loukili Idrissi H. Hannache J.C. Duarte L. Hassani A. Nejmeddine 《Journal of environmental management》2009,91(1):124-132
The application of hypochlorite for the removal of soluble COD, phenolic and polyphenolic like compounds, and other organic compounds responsible for the olive mill wastewater (OOWW) colour has been experimentally studied. After the OOWW filtration on a sand column, the effluent was subjected to a fast liming under optimal conditions. Lime application reduced polyphenols, COD and SS contents to half of their initial values but an important blackening of the treated OOWW was observed, especially when adding high concentrations of lime (10% (W/V) and 15% (W/V)).A second stage of treatment was applied using calcium hypochlorite. In this stage, removal of the studied compounds reached as much as 95% at higher concentrations, and particularly the colouring of OOWW which is generally difficult to eliminate was greatly reduced. The OOWW hypochloration acted through coagulation–flocculation and a rapid oxidation of the organic matter proceeded from the first 5 min. The kinetic study of the degradation of the waste polluting compounds from liming showed that Ca(ClO)2 reacts similarly in the elimination of organic compounds, polyphenols, SS and colouration. The analysis of the organochloride compounds generated by the reaction between hypochlorite and the organic compounds showed that DDD, DDT and the heptachlor contents exceeded the values recommended by the International and European drinking water standards. 相似文献
997.
998.
Parent LM Delorenzo ME Fulton MH 《Journal of environmental science and health. Part. B》2011,46(7):615-622
Limited toxicity data are available for estuarine and marine species and the widely used pyrethroid insecticide, permethrin. This study determined acute effects of permethrin on survival, lipid peroxidation, acetylcholinesterase activity, and splenocyte proliferation for two fish species found in South Carolina estuaries; juvenile red drum (Sciaenops ocellatus) and adult mummichog (Fundulus heteroclitus). Juvenile S. ocellatus were significantly more sensitive than adult F. heteroclitus to permethrin exposure, with a 96-h LC50 value of 8 μg/L determined for red drum compared to 23 μg/L for mummichog. Lipid peroxidation activity of the liver increased in permethrin-treated fish compared to control animals after 24 h and decreased after 96 h. Permethrin had no effect on acetylcholinesterase activity of the brain at the concentrations tested. Permethrin exposure significantly inhibited splenocyte proliferation, indicating an immunosuppressive effect. Most of the effects of permethrin on fish cellular stress enzymes and survival occurred at concentrations much higher than those typically measured in the environment. However, inhibition of splenocyte proliferation in juvenile red drum occurred at approximately twice that of measured permethrin concentrations in surface water. These findings may prove useful to the future management and regulation of pyrethroid insecticide use near estuarine habitats. 相似文献
999.
Shinsuke Iijima Morito Nakamura Akira Yokoi Mitsuhiro Kubota Liwei Huang Hitoki Matsuda 《Journal of Material Cycles and Waste Management》2011,13(3):206-212
For an effective decomposition and removal of organic halogenated compounds, a packed-bed non-thermal plasma reactor with
in situ absorption of the resulting halogenated products by alkaline sorbent incorporated was proposed. In the plasma reactor,
α-Al2O3 particles of 1 and 3 mm (mean particle diameter) were packed as solid dielectric medium to enhance the plasma power density
in the reactor. Further, alkaline sorbent of Ca(OH)2 was doped onto the surface of α-Al2O3 particles, in order to remove halogenated products by in situ absorption with Ca(OH)2. A high-voltage and high-frequency pulsed power of −15 to 15 kV and 1 kHz was applied to the wire electrode of the plasma
reactor by means of a DC power source. In the present study, as the sample of an organic halogenated compound that is most
popularly used, we selected dichloromethane (CH2Cl2), and 500 ppm of the initial concentration of CH2Cl2 was fed into the reactor accompanied by air at a fixed flow rate of 500 × 10−6 m3 min−1 at room temperature. As a result, it was recognized that the amount of CH2Cl2 decomposed by non-thermal plasma in an α-Al2O3 particle bed increased with an increase in plasma input power. The ratio of decomposition of CH2Cl2 was almost 100% at 13 kV of electric power and 1 kHz frequency, and CO2, CH3Cl, COCl2, HCl, and Cl2 were observed as the major reaction products. On the other hand, when CH2Cl2 was introduced into the plasma reactor where α-Al2O3 particles doped with Ca(OH)2 were packed, the ratio of decomposition of CH2Cl2 became higher, compared to the case that α-Al2O3 particles were not doped with Ca(OH)2. Moreover, there were no halogenated by-product gases detected in the outlet gas from the reactor. As the solid reaction
products, CaClOH and Ca(ClO)2·4H2O were detected on Ca(OH)2 by X-ray diffraction. From these findings, it was recognized that CH2Cl2 was decomposed more effectively without producing unwanted harmful halogenated by-products in the proposed non-thermal plasma
reactor where α-Al2O3 particles doped with Ca(OH)2 sorbent were packed. 相似文献
1000.
Novack Aline M. dos Reis Glaydson S. Hackbarth Fabíola V. Marinho Belisa A. Ðolić Maja B. Valle José A. B. Sampaio Carlos H. Lima Eder C. Dotto Guillherme L. Ulson de Souza Antônio Augusto Vilar Vítor J. P. Guelli Ulson de Souza Selene M. A. 《Environmental science and pollution research international》2021,28(19):23568-23581
Environmental Science and Pollution Research - This paper presents the synthesis of a hybrid material through the use of natural pozzolan and titanium(IV) isopropoxide using the sol-gel method and... 相似文献