Genotypic variation of nitrogen use efficiency in Indian mustard

This experiment was conducted to investigate the variation of nitrogen efficiency (NE), nitrogen uptake efficiency (UE), physiological nitrogen use efficiency (PUE) among Indian mustard genotypes, grown under N-insufficient and N-sufficient conditions. Nitrogen efficiency varied from 52.7 to 92.8. Seed yield varied from 1.14 t ha(-1) to 3.21 t ha(-1) under N-insufficient condition, while 2.14 t ha(-1)-3.33 t ha(-1) under N-sufficient condition. Physiological basis of this difference was explained in terms of nitrogen uptake efficiency and physiological nitrogen use efficiency, and their relationship with the growth and yield characteristics. While nitrogen uptake efficiency was positively correlated with plant biomass (0.793**), leaf area index (0.664*), and leaf nitrogen content (0.783**), physiological nitrogen use efficiency is positively correlated with photosynthetic rate (0.689**) and yield (0.814**). This study suggests that genotype having high nitrogen uptake efficiency and high physiological nitrogen use efficiency might help in reducing the nitrogen load on soil without any penalty on the yield.     

Evaluation of relative photonic efficiency in heterogeneous photocatalytic reactors

The evaluation of photonic efficiency in heterogeneous photocatalysis remains elusive because the number of absorbed photons is difficult to assess experimentally. The photonic efficiency of heterogeneous photocatalytic reactors depends on the reactor geometry, irradiation source, and photocatalyst properties. In this work, the relative photonic efficiency of heterogeneous photocatalytic reactors to degrade an azo dye was evaluated using phenol as the standard system. The experimental tests were carried out in a batch reactor under different conditions of pH, catalyst dosage, initial concentration, and ultraviolet (UV) lamps. The kinetics of disappearance of both phenol and azo dye were studied using the initial rate method and were described according to the Langmuir-Hinshelwood (L-H) kinetic model. It was observed that the relative photonic efficiency depends on the adsorption/desorption properties of the photocatalyst.     

Dust collection efficiency analysis in a two-dimensional circulating granular bed filter

Dust collection efficiency data were analyzed to determine better operating conditions for a two-dimensional circulating granular bed filter (CGBF). The dust collection efficiency in the granular bed was affected by the following operating parameters: the louver angle, the solids mass flow rate, and the particle size of the bed material. Experimental results showed that higher dust collection efficiency occurs when the solids mass flow rates were 20.34 +/- 0.24, 21.50 +/- 0.11, and 30.51 +/- 0.57 g/sec at louver angles of 45 degrees, 30 degrees, and 20 degrees, respectively. Optimal dust collection efficiency peaked with a louver angle of 30 degrees. Average particle sizes of bed material by sieve diameters (microm) of 795 microm had higher dust collection efficiency than the average collector particle size of 1500 microm. Dust collection efficiency is influenced by bed material attrition phenomenon, causing dust collection efficiency to decrease rapidly. The dust collection efficiency analysis not only found the system free of design defects but also assisted in the operation of the two-dimensional CGBF system.     

泛比电阻电除尘器收尘性能实验研究

泛比电阻电除尘器是一种具有辅助电极和交错平板收尘电极的新型电除尘器.通过对其伏安特性及除尘效率的试验研究,并与传统线板式静电除尘器进行比较,结果表明辅助电极对电晕电流具有明显的抑制作用,在相同的外加电压下,泛比电阻电除尘器对高比电阻锅炉飞灰的收尘效率比普通的线板式电除尘器明显要高.     

生物转鼓过滤器反硝化净化NO的效率研究

采用自行研制的生物转鼓过滤器(RDB)反硝化净化NO。结果表明,在实验温度为25～30℃、pH为7.0～7.5、转鼓转速为1.0r/min、空床停留时间(EBRT)为86.40s、营养液用量为5.0L、营养液更换频率为0.2L/d的条件下,RDB在30d内完成挂膜;RDB稳定运行期间,当NO进气质量浓度为90～433mg/m3时,NO去除率维持在42.9%～85.2%,平均去除负荷为10.40g/(m3.h);转鼓转速决定了生物膜表面的更新速率和液膜厚度,当转速为0.5r/min时,NO去除率达到最大值(75.0%);将营养液用量控制在1.3～3.0L较为合理;EBRT是决定反硝化效率的重要因素,当EBRT为345.60s时,NO去除率不受其进气浓度的影响,且去除率高达95%以上,当EBRT为43.20s、NO进气质量浓度从98mg/m3增加到1095mg/m3时,NO去除率从62.5%下降到30.7%,当进气负荷为50.00g/(m3.h)时,NO去除负荷达到最大值(27.50g/(m3.h))。     

微气泡曝气O3／H2O2处理RO浓水的效能及影响因素

采用O3／H2O2高级氧化工艺处理炼油厂反渗透（RO）浓水,用溶气泵加压溶气并产生微气泡强化传质,确定装置运行条件,考察气体中臭氧浓度、O3／H2O2初始摩尔比、pH和温度对O3／H2O2处理RO浓水效果的影响,并对RO浓水处理效能进行研究。结果表明,随着气体中臭氧浓度的增加,COD的去除率基本呈线性增加;加入适当量H,0,能提高臭氧氧化RO浓水的效果,O3／H2O2初始摩尔比在0～0．8范围内,COD的去除率先增加后下降,O3／H2O2初始摩尔比为O．5时COD去除率最大;pH从6．84增加到9．01,COD去除率逐渐增大,pH为10．03时COD去除率反而降低;在14～28℃范围内,温度低时,升高温度COD去除率增加较大,温度较高时,升高温度对COD去除率的影响较小。为考察该工艺的稳定性,在H：0：／0,初始摩尔比为O．5、溶液pH为8～9、臭氧浓度为80～100mg／L、温度为10-28℃条件下,对COD为90～140mg／L的RO浓水氧化处理4～10h,出水COD维持在39．9～49．9mg／L,达到《城镇污水处理厂污染物排放标准（GB18918—2002）》中的一级A标准;去除1gCOD消耗031．4～3．3g,消耗0,与H,02的总氧量为2．2～4．4g。     

Long-term efficiency of catalytic converters operating in Mexico City

A 1999 ordinance by the Government of Mexico City bans 1993 model-year vehicles from on-road operation if their catalytic converters are not replaced with new ones. To validate the benefits of this action, we examined three issues related to exhaust emissions of vehicles equipped with catalytic converters. After selecting representative fleets of in-use vehicles, a comparison between emissions and catalyst efficiency in cars with two categories of exhaust emission limits was carried out. For that purpose, two fleets were selected, each made up of 10 vehicles run under similar conditions. A third, larger fleet with emissions control systems was used to evaluate and simulate real-world conditions of vehicles in a controlled laboratory. Finally, the aging effect on the catalytic converter was studied on vehicles run for 100,000 km, replacing their old emission control devices for new ones. The 1991-1992 model-year vehicles showed a high percentage of compliance with the corresponding emissions standard (90%) in comparison with 1993 model-year and later vehicles (Tier 0). However, NOx emissions were higher for the newer vehicles. Fifty percent of the 1991-1992 model-year vehicles evaluated under the official inspection/maintenance (I/M) procedure did not meet the regulated emissions standard when the results were compared with those of the U.S. Federal Test Procedure FTP-75. Our results suggest that the replacement of old catalytic converters with new ones will have little effect on decreasing polluting emissions because these vehicles were in very bad mechanical condition. Results of catalytic activity as a function of mileage indicated inefficient catalyst performance for the fleets tested. All pollutant conversions were below 90% efficiency, and they deteriorated by an average of 30% after the vehicles were run for 100,000 km.     

An evaluation of the urban stormwater pollutant removal efficiency of catch basin inserts.

In a storm sewer system, the catch basin is the interface between surface runoff and the sewer. Responding to the need to improve the quality of stormwater from urban areas and transportation facilities, and spurred by Phase I and II Stormwater Rules from the U.S. Environmental Protection Agency, several companies market catch basin inserts as best management practices for urban water quality management. However, little data have been collected under controlled tests that indicate the pollutant removal efficiency of these inserts when the inflow is near what can be expected to occur in the field. A stormwater simulator was constructed to test inserts under controlled and replicable conditions. The inserts were tested for removal efficiency of total suspended solids (TSS) and total petroleum hydrocarbons (TPH) at an inflow rate of 757 to 814 L/min, with influent pollutant concentrations of 225 mg/L TSS and 30 mg/L TPH. These conditions are similar to stormwater runoff from small commercial sites in the southeastern United States. Results from the tests indicate that at the test flowrate and pollutant concentration, average TSS removal efficiencies ranged from 11 to 42% and, for TPH, the removal efficiency ranged from 10 to 19%.     

溴酸钾对二茂铁(Fc)非均相Fenton效能的影响

研究了KBrO3对二茂铁(Fc)非均相Fenton效能的影响,深入考察了KBrO3对体系中Fc溶解、H2O2分解和羟基自由基(·OH)生成的影响。结果表明,KBrO3的加入对不同反应阶段Fc/Fenton体系的效能均有明显的促进作用,初始阶段主要是由于KBrO3对·OH产生的促进作用所致,后期主要是由于KBrO3促进了体系中Fc的溶解,使得体系中溶解态的Fc催化的均相Fenton反应的比例增加,体系中H2O2的分解加快,·OH的表观生成率增加,进而促进了反应的进行。无KBrO3添加,pH=4,MB初始浓度为10 mg/L,Fc的量为1.6×10-3mol/L,[H2O2]/[MB]=3.14时,45 min时,MB的剩余率为9.1%,105 min时为0。当KBrO3的用量为3×10-4mol/L时,反应45 min后MB的去除率即可达到100%。随着KBrO3浓度的增加,其对Fc/Fenton效能的促进作用增强。     

Computational fluid dynamics analysis of the effects of reactor configuration on disinfection efficiency.

The efficacy of disinfection processes in water purification systems is governed by several key factors, including reactor hydraulics, disinfectant chemistry, and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics (CFD) model to predict velocity fields, mass transport, chlorine decay, and microbial inactivation in a continuous flow reactor. The CFD model was also used to evaluate disinfection efficiency in alternative reactor designs. The CFD reactor analysis demonstrates that disinfection efficiency is affected by both kinetics and mixing state (i.e., degree of micromixing or segregation). Residence time distributions (RTDs) derived from tracer analysis do not describe intrinsic mixing conditions. The CFD-based disinfection models account for reactor mixing patterns by resolution of the reactor velocity field and thus provide a better prediction of microbial inactivation than models that use an RTD.     

紫外线杀菌效能的研究

自来水的消毒目前普遍采用氯及含氯化合物药剂，消毒过程中产生三卤甲烷等致癌或致突变物质，从而造成水体的二次污染，许多国家已经禁止在消毒中使用含氯药剂。因此，具有安全可靠高效杀菌作用的紫外线消毒技术逐渐发展起来，并越来越受到人们的关注。但是紫外线的使用也有一定的限制，通过紫外线照射时间及进水浊度的变化，研究了具有一定照射强度的紫外灯的杀菌效能变化，并得出了紫外线具有最佳杀菌效果的进水极限浊度和照射时间。同时还研究了紫外线对具有不同抗性的细菌的系灭效率，为饮用水和污水的消毒处理提供了实验基础。     

液体旋流分离器分离效率的研究

液体旋流分离器是水环境污染治理的主要设备之一.分离效率是衡量液体旋流分离器分离过程进行完善程度的最重要的技术指标,它能从质与量两方面反映出设备性能的优劣.当前液体旋流分离器设计过程还缺少具体量化的理论依据,为了给液体旋流分离器的设计提供理论依据,通过液体旋流分离器从水中分离固体粒子的性能实验,得出了液体旋流分离器各部结构尺寸、形状、相对比例对分离效率的不同影响程度,提出了结构参数的最佳取值范围.按照本研究提出的设计原则和方法,可以制造出性能优良的液体旋流分离器.     

Revised air-exchange efficiency considering occupant distribution in ventilated rooms

Air-exchange efficiency is widely used to indicate the ventilation effect and indoor air quality in ventilated rooms. However, it does not take occupant distribution in the room into account and is thus limited. In this paper, a revised air-exchange efficiency (occupant air-exchange efficiency) that differentiates between different zones by considering different occupancy in each zone is developed. Results from studies of a large-space ventilation case, a personalized ventilation case, and a displacement ventilation case show that occupant air-exchange efficiency can better be used to evaluate the ventilation effect of a room.     

Technological efficiency improvements: beyond the prospects of first-law efficiencies

Efficiency improvements of technology are said to be one of the most important possibilities to satisfy the energy requirements of a growing global population and to mitigate adverse energy-related environmental impacts, such as climate change, at the same time. On the basis of the classical concept of first-law efficiency, however, conventional energy analyses lead to the impression that efficiency improvement potentials are almost exhausted. This paper explains why prevailing energy conversion efficiencies are grossly overestimated when measured in terms of first-law efficiencies. Using a stylised example, we compare the concepts of first-law and second-law efficiency. Our comparison indicates that estimates of current efficiency improvement potentials depend heavily upon the efficiency concept employed. In fact, there still seems to be much scope for efficiency improvements.     

Regional effects and efficiency of flue gas desulphurization in the Carpathian Basin

Although sulphur emissions (mainly as SO₂) have been continuously decreasing over the last 20 years in most western industrialized countries, localized SO₂ problems still exist in conjunction with strong local emission, meteorological, and topographical factors. In this study, the effect of supplementary installed flue gas desulphurization (FGD) units at high-capacity power plants on regional air pollution in the Carpathian Basin is investigated. The dispersion and accumulation of the SO₂ air pollutant are studied with the regional three-dimensional on-line atmosphere-chemistry model REMOTE. The changes in the SO₂ air pollution are investigated by parallel simulations in a case study, where the single modified parameter is the SO₂ emission rate. The results show that FGD units significantly reduce the horizontal and the vertical dispersion of the emitted SO₂, and its transboundary transport, too. Beside the SO₂ removal efficiency, the dispersion and accumulation also depend on the seasonal weather conditions. During winter, the dispersion and accumulation are higher than in other seasons. Due to this phenomenon, higher SO₂ removal efficiency is needed to guarantee similar air quality features like in the other seasons.     

Influence of the inlet air in efficiency of photocatalytic devices for mineralization of VOCs in air-conditioning installations

Nowadays, a large proportion of photocatalytic oxidation (PCO) devices are being implemented in heating, ventilation and air-conditioning systems. However, no systematic studies have been carried out regarding the influence of inlet air preconditioning. To analyse the impact of the inlet air-conditions into photocatalytic efficiency, a simulated air-conditioning duct with flowing gas through inside was designed. Isobutylene was chosen as the target VOCs. The concentration in the gas phase was monitored using a photoionization detector. The influence of flow rate, relative humidity and temperature on the VOC removal efficiency was analysed. Experimental results were presented in terms of gas-removal efficiency (η) and clean air delivery rate (CADR) and analysed on a kinetic basis. From them, the weight of each parameter in the global process has been determined, from bigger to smaller contribution, flow>>temperature>relative humidity. Also, the relevance of the inlet air conditions has been illustrated in a model room in order to determinate the time necessary to obtain a threshold value accomplishing with enough air quality and the energy consumption of the device. Additionally, the photocatalytic decontamination has been assimilated to the “air exchange rate”, a parameter commonly used in indoor air quality studies. The results show that preconditioning of air can improve the efficiency of photocatalytic devices and bring important energy savings.     

Remediation efficiency of vapour extraction of sandy soils contaminated with cyclohexane: Influence of air flow rate, water and natural organic matter content

This work reports the analysis of the efficiency and time of soil remediation using vapour extraction as well as provides comparison of results using both, prepared and real soils. The main objectives were: (i) to analyse the efficiency and time of remediation according to the water and natural organic matter content of the soil; and (ii) to assess if a previous study, performed using prepared soils, could help to preview the process viability in real conditions. For sandy soils with negligible clay content, artificially contaminated with cyclohexane before vapour extraction, it was concluded that (i) the increase of soil water content and mainly of natural organic matter content influenced negatively the remediation process, making it less efficient, more time consuming, and consequently more expensive; and (ii) a previous study using prepared soils of similar characteristics has proven helpful for previewing the process viability in real conditions.     

SBR-BAF工艺处理效能的试验研究

根据生物除磷和脱氮的机理,污水的脱氮除磷存在基质竞争和泥龄等方面的矛盾。为了分析和解决这个问题,设计开发了一种新的污水生物处理工艺——SBR-BAF复合工艺,并以模拟城市生活污水为处理对象对该工艺的处理效能进行了考察。试验结果表明,系统对COD（不计BAF加入的外碳源）、TP、NH⁺₄-N和TN的平均去除率分别为96%、98%、93%和84%,出水中COD、TP、NH⁺₄-N和TN的平均浓度分别为20、0.23、3.24和7.68 mg/L,各项水质指标均达到《城镇污水处理厂污染物排放标准》（GB 18918-2002 ) 规定的一级标准中的A标准。     

水质净化高效复合微生态制剂的研制

在室内模拟条件下,采用正交实验的方法对光合细菌、枯草芽孢杆菌和反硝化细菌的复配比例进行了研究,筛选一种用于水产养殖水质净化的高效复合微生态制剂。结果表明,当光合细菌(菌细胞浓度约为2×109CFU/mL)、枯草芽孢杆菌(菌细胞浓度约为8×108CFU/mL)和反硝化细菌(菌细胞浓度约为8×108CFU/mL)按菌液体积比为1∶2∶1进行复配利于水中溶解氧的提高和COD、氨氮、亚硝态氮、硝态氮的降解。验证实验表明,筛选组合各指标均优于商品微生态制剂和空白对照,其中溶解氧含量显著高于商品微生态制剂EM和复合芽孢菌处理,在实验第5天对COD的降解率为95%,显著优于EM和复合芽孢菌处理的66.3%和47.9%,实验第7天对氨氮、亚硝态氮和硝态氮的降解率分别达到70%、89%和56%。