半导体制程废气处理技术实践

讨论了半导体制造废气处理技术与排放,包括热排气、酸性排气、碱性排气和有机排气这四种工艺废气处理设备的应用和处理原理,以及在实际的操作运行中不同系统控制参数对处理效率的影响,并通过实验确定合理的参数设定范围。特别阐述了有机废气处理技术和相关处理设备的应用和操作运行,以及实现系统高效节能运行的技术实践,对半导体厂实现环境保护以及降低气态分子级污染物对生产的影响提供了现实可行的操作依据。

Effects of Organic Manure Applications on Methane and Nitrous Oxide Emissions in Paddy Fields

This study was carried out in paddy fields to explore how organic manure applications would affect greenhouse emissions in South China. The results showed that the seasonal emission of CH4 under the chemical fertilizer （CF） treatment was 271.47 kg/hm^2. In comparison, the seasonal emissions of CH4 under the treatment of pig manure （PM）, chicken manure （CM） and rice straw （RS） increased by 50.61,260.22 and 602.82 kg/hm^2, respectively. N2O emission under the CF treatment was 1.22 kg/hm^2, while the N20 seasonal emissions under tile PM, CM and RS treatment decreased by 23.6% （P〈0.05）, 31.7% （P〈0.05） and 30.9% （P〈0.05）, respectively. Meanwhile, the readily oxidized organic carbon （which was oxidized by 167 mmol/L potassium permanganate, ROC167） of manure, paddy soil Eh value and temperature could also affect the CH4 emissions. The average yield of the organic fertilizer treatments increased by 6.8% compared with that of the CF treatment. Among all the organic fertilizer treatments, the PM treatment offered the lowest global warming potential and greenhouse gas intensity, in which the PM was of no significant difference from NF （no fertilizing） and CF. Therefore, the pig manure is capable of coordinating the relationship between environment and yield, and it also has a low ROC167 content, so the PM is considered worthy of recommendation.

Commercial Application of Technology for Catalytic Combustion of Waste Gases from Wastewater Treatment System in Petrochemical Enterprises

The catalytic combustion technology for treating waste gases exiting from wastewater treatment system and oil separators in petrochemical enterprises was introduced in this article. Commercial application of this technology showed that the process ＂desulfurization and total hydrocarbon concentration homogenizationcatalytic combustion＂ and the associated WSH-1 combustion catalyst were suitable for treating volatile organic gases emitted from the oil separators, floatation tanks, inlet water-collecting well, waste oil tanks, etc. The commercial unit was equipped with an advanced auto-control system, featuring a simple operation and low energy consumption with good treatment effect. The purified gases could meet the national emission standard.

Overview of Past, Present and Future Marine Power Plants

In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.

Safe Degradation of the Pesticide Hexachlorcyclohexane by Molten Salt Oxidation

This study was motivated by the world interest in the development of advanced processes of waste decomposition, due to the need of safer decomposition processes, particularly for the POPs （Persistent Organic Pollutants） and the organochlorines. A tendency observed at several countries is the adoption of progressively more demanding legislation for the atmospheric emissions from the waste decomposition processes. The suitable final disposal of hazardous organic wastes such as PCBs （Polychlorinated Biphenyls）, pesticides, herbicides and hospital residues constitutes a serious problem. In some point of their lifecycles, these wastes should be destroyed, in reason of the risk that they represent for the human being, animals and plants. The process involves a chemical reactor containing molten salts, such as sodium carbonate or some alkaline carbonates mixtures to decompose the organic waste. The decomposition is performed by submerged oxidation. Waste is injected below the surface of a turbulent salt bath along with the oxidizing agent. Decomposition of halogenated compounds, among which some pesticides, is particularly effective in molten salts. The process presents properties such as intrinsically safe control of organochlorine emissions. This work describes the process developed at IPEN/CNEN-SP （Nuclear and Energetic Research Institute/Brazilian Nuclear Energy Commission） for complete thermal decomposition of hazardous wastes through oxidation submerged in molten salts.

Atmospheric Pollution due to Road Traffic Case of the Greater Casablanca Region

In the Greater Casablanca, road transport is the second largest emissions source of gaseous pollutants and particles after the industry [ 1 ]. The emitters are mobile and include different categories of vehicles in circulation, in the road network of the region [2]. Air emissions from road transport considered in this study are the exhaust emissions from combustion of fuel during vehicle movement. This is mainly SO2 （sulfur dioxide）, NOx （nitrogen oxides）, CO （carbon monoxide）, CO2 （carbon dioxide）, SP （suspended particulate） [3], VOC （volatile organic compounds）, benzene, lead Pb and cadmium. These emissions depend mainly on the technology of the vehicle （type, fuel, engine size, and age）, the vehicle speed, the engine temperature and ambient temperature [4].

Mitigating greenhouse gas of chemical fertilizer with farmland emissions through replacement organic manure in a temperate

Burning crop residues and excessive use of chemical fertilizers results in an enormous waste of bio- logical resources, which further weakens the potential capacity of the agro-ecosystem as a carbon sink. To explore the potential of farmlands acting as a carbon sink without yield losses, we conducted an experiment on a temperate eco-farm in eastern rural China. Crop residues were applied to cattle feed, and the composted cattle manure was returned to cropland with a winter wheat and maize rotation. Four different proportions of fertilizers were designed： 100 % cattle manure, 100 % mineral nitrogen, 75 % cattle manure plus 25 % mineral nitrogen, and 50 % cattle manure plus 50 % mineral nitrogen. Crop yield and greenhouse gas （GHG） emissions were carefully calculated according to the Intergovernmental Panel on Climate Change （IPCC） Guidelines for National Green- house Gas Inventories 2006. Our results showed that replacing chemical fertilizer with organic manure signifi- cantly decreased the emission of GHGs. Yields of wheat and corn also increased as the soil fertility was improved by the application of cattle manure. Totally replacing chemical fertilizer with organic manure decreased GHG emissions, which reversed the agriculture ecosystem from a carbon source （＋2.7 t CO_2-eq. hm-2 year-1） to a carbon sink （-8.8 t CO_2-eq. hm^-2 year^-1）. Our findings provide useful insights for improving agricultural ecosystems under global change scenarios.

Influence of bulking agents on CH_4,N_2O,and NH_3 emissions during rapid composting of pig manure from the Chinese Ganqinfen system

Mismanagement of the composting process can result in emissions of CH4,N2O,and NH3,which have caused severe environmental problems.This study was aimed at determining whether CH4,N2O,and NH3 emissions from composting are affected by bulking agents during rapid composting of pig manure from the Chinese Ganqinfen system.Three bulking agents,corn stalks,spent mushroom compost,and sawdust,were used in composting with pig manure in 60 L reactors with forced aeration for more than a month.Gas emissions were measured continuously,and detailed gas emission patterns were obtained.Concentrations of NH3 and N2O from the composting pig manure mixed with corn stalks or sawdust were higher than those from the spent mushroom compost treatment,especially the sawdust treatment,which had the highest total nitrogen loss among the three runs.Most of the nitrogen was lost in the form of NH3,which accounts for 11.16% to 35.69% of the initial nitrogen.One-way analysis of variance for NH3emission showed no significant differences between the corn stalk and sawdust treatments,but a significant difference was noted between the spent mushroom compost and sawdust treatments.The introduction of sawdust reduced CH4emission more than the corn stalks and spent mushroom compost.However,there were no significant differences among the three runs for total carbon loss.All treatments were matured after 30 d.

Influence of Soil Organic Carbon on Greenhouse Gas Emission Potential After Application of Biogas Residues or Cattle Slurry:Results from a Pot Experiment

A change in the European Union energy policy has markedly promoted the expansion of biogas production. Consequently, large amounts of nutrient-rich residues are being used as organic fertilizers. In this study, a pot experiment was conducted to simulate the high-risk situation of enhanced greenhouse gas （GHG） emissions following organic fertilizer application in energy maize cultivation. We hypothesized that cattle slurry application enhanced CO2 and N20 fluxes compared to biogas digestate because of the overall higher carbon （C） and nitrogen （N） input, and that higher levels of CO2 and N20 emissions could be expected by increasing soil organic C （SOC） and N contents. Biogas digestate and cattle slurry, at a rate of 150 kg NH＋-N ha-1, were incorporated into 3 soil types with low, medium, and high SOC contents （Cambisol, Mollic Gleysol, and Sapric Histosol, termed Clow, Cmedium, and Chigh, respectively）. The GHG exchange （CO2, CH4, and N20） was measured on 5 replicates over a period of 22 d using the closed chamber technique. The application of cattle slurry resulted in significantly higher CO2 and N20 fluxes compared to the application of biogas digestate. No differences were observed in CH4 exchange, which was close to zero for all treatments. Significantly higher CO2 emissions were observed in Chigh compared to the other two soil types, whereas the highest N20 emissions were observed in Cmedium. Thus, the results demonstrate the importance of soil type-adapted fertilization with respect to changing soil physical and environmental conditions.