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1.
1. Introduction With the development of transportation, more and more road tunnels, especially the long tunnels, such as Erlangshan Tunnel (4176 m, China), Arlberg Tunnel (13972 m, Austria), Kan-etsu Tunnel (11055 m, South tube, Japan) and Laerdal Tunnel (24510m, Norway) have been built on the highway lines [1]. In a road tunnel, the exhaust gases given off by automobile engines, such as smoke, carbon monoxide (CO), oxynitride (NOx), hydrocarbon, etc., and dust produced by the passing a…  相似文献   

2.
The naphthalene decomposition in a corona radical shower discharge (CRS) was investigated, with attention paid to the influences of voltage and initial naphthalene density. The OH emission spectra were investigated so as to know the naphthalene decomposing process. The by-products were analyzed and a decomposing theory in discharge was proposed. The results showed that higher voltage and relative humidity were effective on decomposition. The initial concentration affected the decomposing efficiency of naphthalene. When the initial naphthalene density was 17 mg/m3, the decomposition rate was found to be 70% under 14 kV. The main by-products were carbon dioxide and water. However, a small amount of carbonic oxide, 1,2-ethanediol and acetaldehyde were found due to the incomplete oxidization.  相似文献   

3.
Increasingly high requirement driven by environmental concern leads to more rigorous standards for sulfur dosage in fuel. Natural gas desulfurization is an important unit for industrial natural gas process. Catalytic membrane reactor for sulfur compounds removal is a newly emerged and integrated membrane technology. We reviewed the current progress for desulfurization of natural gas with membrane process, and predicted that the process combined with catalytic membrane reactor and microwave irradiation for desulfurization of natural gas might be an integrated and promising unit for large scale desulfurization with high efficiency.  相似文献   

4.
Performance of biological phosphorus removal in the oxic-settling-anaerobic (OSA) process was investigated. Cell staining and fluorescent in situ hybridization (FISH) were used to analyze characteristics and microbial community of sludge. Experimental results showed that phosphorus removal efficiency was near 60% and the amount of biological phosphorus accumulation in aerobic sludge of the OSA system was up to 26.9 mg/g. Biological phosphorus removal efficiency was partially inhibited by carbon sources in the continuous OSA system. Contrasted to the OSA system, biological phosphorus removal efficiency was enhanced by 14% and the average total phosphorus (TP) contents of aerobic sludge were increased by 0.36 mg/g when sufficient carbon sources were supplied in batch experiments. Staining methods indicated that about 35% of microorganisms had typical characteristics of phosphorus accumulating organisms (PAOs). FISH analysis demonstrated that PAOMIX-binding bacteria were predominant microbial communities in the OSA system, which accounted for around 28% of total bacteria.  相似文献   

5.
The simultaneous removal of ethyl acetate, benzene and toluene with relatively low or high initial concentration is studied using a laboratory scale gliding arc gas discharge (GA) reactor. Good decomposition efficiencies are obtained which proves that the GA is effective for the treatment of volatile organic compounds (VOCs) with either low or high concentration. A theoretical decomposition mechanism is proposed based on detection of the species in the plasma region and analysis of the decomposition by-products. This preliminary investigation reveals that the GA has potential to be applied to the treatment of exhaust air during color printing and coating works, by either direct removal or combination with activated carbon adsorption/desorption process.  相似文献   

6.
The optimal operation conditions in an anoxic sulfide oxidizing (ASO) bioreactor were investigated. The maximal removal rates for sulfide and nitrate were found to be 4.18 kg/(m3·d) and 1.73 kg/(m3·d), respectively. The volumetrical volumetric loading rates (LRs) observed through decreasing hydraulic retention time (HRT) at fixed substrate concentration are higher than those by increasing substrate concentration at fixed HRT. The sulfide oxidation in ASO reactor was partially producing both sulfate and sulfur; but the amount of sulfate produced was approximately one third that of sulfur. The process was able to tolerate high sulfide concentration, as the sulfide removal percentage always remained near 99% when influent concentration was up to 580 mg/L. It tolerated relatively lower nitrate concentration because the removal percentage dropped to 85% when influent con- centration was increased above 110 mg/L. The process can tolerate shorter HRT but careful operation is needed. Nitrate conversion was more sensitive to HRT than sulfide conversion since the process performance deteriorated abruptly when HRT was decreased from 3.12 h to 2.88 h. In order to avoid nitrite accumulation in the reactor, the influent sulfide and nitrate concentrations should be kept at 280 mg/L and 67.5 mg/L respectively. Present biotechnology is useful for removing sulfides from sewers and crude oil.  相似文献   

7.
In order to reduce the microfauna leakage risk from a granular biological activated carbon (GBAC) reactor which employs granular activated carbon (GAC) as adsorption media in drinking water advanced treatment, a novel fiber and granular biological activated carbon (FGBAC) reactor which employs both GAC and activated carbon fiber (ACF) as adsorption media, was developed. The results showed that the species composition of microfauna leaking from FGBAC reactor is almost similar to that leaking from GBAC reactor, however the densities of microfauna leaking from FGBAC reactor is reduced by 26%-81% compared to those leaking from GBAC reactor. In addition, compared to GBAC reactor, FGBAC reactor can increase the removal efflciencies of chemical oxygen demand (COD) and turbidity by 7% and 10%, respectively, during the stable operation period of reactor.  相似文献   

8.
循环流化床烟气脱硫实验研究(英文)   总被引:2,自引:0,他引:2  
本文在一变速循环流化床反应器试验台上进行了烟气脱硫实验.当Ca/S摩尔比为1.1,并用两相流喷嘴向反应器内喷入适量水时,脱硫效率可以达到80%以上.  相似文献   

9.
An expanded granular sludge bed (EGSB) reactor inoculated with anaerobic granular sludge was started up with its COD removal performance, self-balancing of pH, biogas production rate and characteristics of the granular sludge during the start-up period being investigated. The results indicated that the EGSB reactor can be started up successfully in 27 d by increasing the organic loading rate rapidly. The removal efficiency of COD was maintained above 93% with influent COD concentration of 25 000 mg/L and OL...  相似文献   

10.
An improved configuration of the membrane stack was adopted in the electrodeionization (EDI) cell to prevent precipitation of bivalent metal hydroxide during the running. The operational parameters that influenced the removal of copper ions from the dilute solution were optimized. The result showed that a moderate decrease in the inlet pH value and a moderate increase in the applied voltage could achieve a better removal effect. The steady process of electroplating wastewater treatment could be achieved with a removal efficiency of more than 99.5% and an enrichment factor of 5-14. The concentration of copper in purified water was less than 0.23 mg/L. This demonstrated the applicability of recovering heavy metal ions and purified water from electroplating effluent for industrial reuse.  相似文献   

11.
采用常压吸附法研究了膨胀石墨吸附剂在二氧化碳/氮气体系中对二氧化碳的动态吸附性能,比较了其吸附量、穿透曲线和吸附性能的差异.研究了膨胀石墨的比表面积,孔径分布等因素对其二氧化碳吸附性能的影响.结果表明:膨胀体积越大的膨胀石墨,其对二氧化碳的吸附能力越强,最高可达190 mg/g以上.其吸附量随温度升高而呈现下降趋势,但在30℃时吸附量仍达到90 mg/g以上.  相似文献   

12.
A high-energy pulse power source applied for study-ing solidification of metals and a Rogowski coil formeasuring strong pulse current were developed accord-ing to the requirement of the present experi ment.Thevariation of electrical current during the discharge ofpulse power source was analyzed.Furthermore,thequantitative relation between peak current,pulsewidth and pulse frequencyetc.versusvoltage,capa-citance and transmissionline of discharging circuit wasexamined.Combined with the component…  相似文献   

13.
Removal of chromium (VI) dissolved in water by intermittent foam separation was implemented with cetyl trimethy-ammonium bromide as surfactant. The influence of various factors on removal efficiency was systematically studied. The removal efficiency has a maximum value near pH 4.0; thus, most experiments were carried out at pH 4.0. The orthogonal experiment was conducted to confirm the optimal operating parameters. The orthogonal experimental results show that when the liquid feed concentration is 10 mg/L, the pH value of feed solution is 4.00, air flow rates 0.9 L/min, surfactant dosage is 300 mg/L, the maximum removal efficiency of chromium (VI) reaches 97.80%, and condense multiple reaches 1 711. The kinetic test indicates that the foam separation of chromium is a first-order process. The equivalent rate constant calculated from the slope is 0.406 4, and the equivalent rate equation is obtained.  相似文献   

14.
UrbanareapollutionofShijiazhuangcityisnowacauseofmajorconcernduetorapidindustrializationandin creasedgrowthofautomobiles .Theambientairqualityhasdeterioratedtosuchanextentthatitposesaserioushealthhazard .Considerableeffortsarebeingtakenbyregu latorya genciestomonitorthequalityofairandtomaintainpollutionlevelswithinpermissiblelimits .Sothelong term (to 2 0 10 )andshort term (to 2 0 0 5 )controlstrategieshavebeende signed .  Thelong termcontrolstrategyhastwoschemes.Thefirstschemeincludesthefo…  相似文献   

15.
本介绍了在增湿活化反应器中喷入雾化水滴采用生石灰和熟石灰烟气脱硫的试验结果.研究了钙硫摩尔比、烟气露点温距、二氧化硫浓度和烟气流速等因素对脱硫效率和脱硫剂钙利用率的影响规律.比较了2种脱硫剂的脱硫特性,分析了喷水增湿改善脱硫效率的机理.结果表明,喷水增湿活化明显改善了2种脱硫剂的活性,生石灰比熟石灰具有价格优势因而市场前景更好.  相似文献   

16.
We evaluated several different pre-oxidation treatments, namely the introduction of either potassium permanganate (KMnO4), chlorine (Cl2), or both to remove manganese (Mn) from the Qiantang River source water. Our results showed that Mn removal percentages were 12.7%, 71.0%, 17.4% and 58.7% when none of the oxidants, KMnO4 only, Cl2 only, or both oxidants were added, respectively. Furthermore, a field study showed that when the available Mn concentration in the source water was 0.14 mg/L, it could be reduced to less than 0.05 mg/L when a solution of KMnO4 (0.47 mg/L) was added as the oxidant.  相似文献   

17.
以半导体材料二氧化钛为催化剂,对偶氮染料甲基橙溶液进行了电催化氧化降解实验;考察了催化剂量、槽电压、pH值、电解质浓度、反应时间等因素对处理效果的影响.实验结果表明:二氧化钛的催化效果显著,其色度和COD去除效果可比无催化剂时效果分别提高35%和28%;去除机制主要是电催化体系中产生的·OH对有机物的氧化、降解.  相似文献   

18.
A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g.h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy Ea of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the range of 10-20 nm.  相似文献   

19.
Study on anaerobic treatment of wastewater containing hexavalent chromium   总被引:6,自引:0,他引:6  
A self-made anaerobic bio-filter bed which was inoculated with special sludge showed high efficiency in removing hexavalent chromium. When pump flow was 47 ml/min and CODCr of wastewater was about 140 mg/L, it took 4 h to decrease the Cr^6 concentrations from about 60 mg/L to under 0.5 mg/L, compared with 14 h without carbon source addition. Cr^6 concentrations ranged from 64.66 mg/L to 75.53 mg/L, the system efficiency was excellent. When Cr^6 concentration reached 95.47 rag/L, the treatment time was prolonged to 7.5 h. Compared with the contrast system, the system with trace metals showed clear superiority in that the Cr^6 removal rate increased by 21.26%. Some analyses also showed that hexavalent chromium could probably be bio-reduced to trivalent chromium, and that as a result, the chrome hydroxide sediment was formed on the surface of microorganisms.  相似文献   

20.
The research of high-brightness organic light-emitting diodes,as an important branch of organic light-emitting diodes (OLEDs),makes it possible for achieving high-brightness lighting source and lasing.Heat dissipation and efficiency roll off,as two main factors,affect the brightness of the OLEDs heavily.In this paper,high-brightness OLEDs are obtained by utilizing pulse voltage,small areas and micro-cavity structure to minimize the effect of the two factors.The major advances,ongoing challenges and future p...  相似文献   

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