电改电袋复合除尘器在220MW机组上的应用

分析了某电厂220MW机组燃煤锅炉电改电袋复合除尘器的设计优化、运行调试和关键参数，重点对比了改造后电袋复合除尘器和常规袋式除尘器的清灰周期、运行阻力等参数变化，为燃煤锅炉电改电袋复合除尘器设计和运行维护的提供参考。     

电袋复合除尘器气流分布技术及评判标准研究

从电袋复合除尘器的基本原理出发,提出对其进行气流组织的三个关键点,并从理论上对影响电袋复合除尘器性能的烟气冲刷速度、逆重力向速度分量（CANE速度）、静电区除尘效率、静电区气流均匀性系数、净气室及出口烟道的设计等方面进行了研究。     

330MW机组电改电袋除尘器清灰制度优化和喷吹参数设定探讨

分析了电袋复合除尘器袋式除尘单元清灰效果的影响因素,并对某热电厂330MW机组燃煤锅炉电改电袋复合除尘器的清灰制度进行了优化。重点对比了优化前后的电袋复合除尘器的清灰频率、清灰周期、运行阻力等参数的大小,优化结果可以作为大型燃煤锅炉电改电袋复合除尘器清灰制度的借鉴。     

电-袋复合除尘器性能对比试验研究

通过现场工业试验，对比了不同过滤风速下，袋式除尘器和电-袋复合除尘器出口烟尘排放浓度、PM10分级效率和压力损失上升速率三个重要性能指标，给出了电-袋复合除尘器合理的过滤风速取值范围，为其大型化设计和推广应用提供了依据。     

电除尘器改造为电袋复合除尘器的实践

介绍了扬子热电厂1~7号炉电除尘器改造为电袋复合除尘器的工程实践,分析了电袋复合除尘器的关键技术及运行情况。改造后,电袋复合除尘器出口烟尘浓度≤30mg/m3,满足排放要求。     

300MW机组电袋复合除尘器的应用探讨

通过技术、经济比较，确定了宁夏大坝发电有限责任公司3号机组电除尘器改造为电袋复合除尘器的方案。改造后电袋除尘器各项指标均达到设计要求，保证300MW发电机组满负荷运行。     

卧式电袋复合除尘器及应用

卧式电袋复合除尘器是电袋复合除尘技术的应用之一,具有结构优、性能好、经济性和可靠性高的特点,适用于现有电除尘提效改造和煤质变化大、收尘难度大的新建除尘项目.以50 MW、125 MW和200 MW除尘器改造应用为例,论述卧式电袋复合除尘器的优点.     

电—袋复合除尘器捕集微细粒子的理论浅析

依据袋式除尘器的捕集机理,定性分析了静电力对增强电—袋复合除尘器捕集亚微米微细粒子能力以及降低袋式除尘器压力损失的影响,为进一步研究电—袋复合除尘器过滤机制提供参考。     

电袋复合除尘器气流分布的研究与应用

针对电袋复合除尘器气流分布存在的问题，提供了一种技术方法，通过工厂模型试验进行了研究分析，并成功应用于实际工程中，发挥了电袋复合除尘器的优势，提高了对细颗粒物粉尘的捕集效果。     

浅析电袋除尘器滤袋的设计选型

扬子石化热电厂1～9号炉电除尘器全部改造为电袋除尘器后,出口粉尘浓度均满足排放要求。但运行中发现5、6、9号炉电袋除尘器滤袋破损较多,影响了电袋除尘器的安全稳定运行。分析了这3台炉滤袋破损的原因,提出在电除尘器改造电袋除尘器的工程实践中滤袋选型是个关键。滤袋设计时应以滤料的连续长期使用温度来选型,同时应重视设计煤种和较核煤种的选取,袋区的过滤风速以1.0～1.2m/s为宜。     

Programs assessing implementation and effectiveness of state forest practice rules and BMPs in the West

The major forest nonpoint source control programs in the West are largely regulatory, either under forest practices acts (California, Idaho, New Mexico, Nevada, Oregon, and Washington) or a streamside management act (Montana). These programs and the specific rules they enforce continue to undergo intensive scrutiny. Still, the questions are the same for these regulatory programs as for states that base nonpoint source control on voluntary BMPs (Arizona, Colorado, Utah, Wyoming). Are the rules or BMPs being applied, and are they effective in reducing nonpoint source pollution to levels that protect beneficial uses of water? The level of debate about forestry in the West has resulted in detailed monitoring and research to answer these questions. In the past, state agencies have assumed levels of BMP compliance based on the percent of operations without enforcement actions. These estimates are being replaced by statistically valid and reproducible monitoring of forest practices rules and BMP compliance levels. BMP effectiveness is being assessed using both qualitative and quantitative methods. This can involve field assessments, process-based research, and control watershed studies. Some trend monitoring is also beginning. With the regional implementation rate for forestry BMPs at about 94% and rising, it is likely that effectiveness testing will continue to be a priority and consume the majority of assessment resources for this region.     

Hysteresis in Reversal of Central European Mountain Lakes from Atmospheric Acidification

Extremely high emissions of S and N compounds in Central Europe (both 280 mmol m^-2 yr^-1) declined by 70and 35%, respectively, during the last decade. Decreaseddeposition rates of SO₄ ^-2, NO₃ ^-, and NH₄ ⁺ in the region paralleled emission declines. The reduction in atmospheric inputs of S and N to mountain ecosystemshas resulted in a pronounced reversal of acidification in the Tatra Mountains and Bohemian Forest lakes. Between the 1987–1990and 1997–1999 periods, concentrations of SO₄ ^-2 and NO₃ ^- decreased (average ± standard deviation) by 22±7 and 12±7 mol L^-1, respectively, in theTatra Mountains, and by 19±7 and 15±10 mol L^-1, respectively, in the Bohemian Forest. Their decrease was compensated in part (1) by a decrease in Ca²⁺ + Mg²⁺ (17±7 mol L^-1) and H⁺ (4±6 mol L^-1), and an increase in HCO₃ ^-(10±10 mol L^-1) in the Tatra Mountains lakes, and (2) by a decrease in Al (7±4 mol L^-1), Ca²⁺ + Mg²⁺ (9±6 mol L^-1), and H⁺ (6±5 mol L^-1), in Bohemian Forest lakes. Despite the rapid decline in lake water concentrations of SO₄ ^-2 and NO₃ ^- in response to reduced S and N emissions, their present concentrations in some lakes are higher than predictionsbased on observed concentrations at comparable emission rates during development of acidification. This hysteresis in chemical reversal from acidification has delayed biological recovery of the lakes. The only unequivocal sign of biological recovery hasbeen observed in erné Lake (Bohemian Forest) where a cladoceran species Ceriodaphnia quadrangular has recentlyreached its pre-acidification abundance.     

Reconstruction of Long-Term Changes in Lake water Chemistry,Zooplankton and Benthos of a Small,Acidified High-Mountain Lake: Magic Modelling and Palaeolimnogical Analysis

Starolesnianske pleso is a small and shallow acid lake in the High Tatra Mountains, situated at 2000 m above sea level, on granitic bedrock, with sparse and thin soil cover. When detailed measurements began in the 1980s Starolesnianske pleso had pH below 5 and only one species of cladoceran zooplankton, the ubiquitous Chydorus sphaericusPalaeolimnological investigations show changes in cladoceran zooplankton and chironomid zoobenthic assemblages since about 1920 and a major change in 1970–1980. The dynamic acidification model MAGIC was used to reconstruct changes in water chemistry over the past 150 years. The results from MAGIC agree well with the sediment record; pH levels gradually decreased from 6.5 in the mid-1800s to about 5.6 in 1920 (first response in biota) to below 5.0 by 1970, and concentrations of inorganic aluminium rose dramatically beginning about 1960. In the 1990s the lake water chemistry showed clear signs of reversal in acidification brought about by a major decline in S deposition.     

Heavy Metals Removal by Biosorption and Flotation

The removal of a mixture of heavy (toxic) metal cations (copper, nickeland zinc) from liquid effluents was investigated in this study at pilotscale, using counter-current contact mode. The innovative processinvolved the abstraction of metal ions onto fungal biosorbents, followedby the application of flotation for the subsequent solid/liquid separationof biomass particles. The ability of microorganisms to remove metal ionsfrom aqueous solutions is a well-known phenomenon. Nevertheless,engineering considerations are very important in decisions, concerningthe commercial future of biosorption and practical solutions are neededfor certain problems, such as the efficient post-separation ofmetal-loaded biomass. The two processes (flotation and biosorption) caneffectively operate in combination, in what it was termed biosorptiveflotation process. The sorbents may be recycled, after appropriate elutionof metals, as well as the treated (clean) water.     

Selection of Autochthonous Plant Species from SE Spain for Soil Lead Phytoremediation Purposes

Mining activity in SE of Spain, in the west Mediterranean coast, originated more than two millenniums ago. It has generated huge areas affected by heavy metals contamination, especially of lead, which is possibly one of the most important. Investigations related to the selection of autochthonous plant taxa from a typical Spanish Mediterranean area, useful for phytoextraction and phytostabilization purposes in these polluted areas are shown. Under these edaphoclimatic conditions 12 interesting species were considered, from them six taxa were chosen for further studies. Some plant species have been proposed either for phytoextraction or phytostabilization purposes. Recommendations for further research have been discussed.     

Concentrations and Pools of Heavy Metals in Urban Soils in Stockholm,Sweden

The concentrations of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb andZn) and arsenic (As) were surveyed and the metal pools estimatedin soils in Stockholm Municipality. The sampling sites were distributed all over the entire municipality with a higher sampling density in the city centre. Soils were sampled to a maximum depth of 25 to 60 cm. Soil texture, total-C content, electrical conductivity and pH were analysed. Heavy metal concentrations were determined after wet digestion with boiling7 M HNO₃.The results showed a wide range in heavy metal concentrations, as well as in other soil properties. The city centre soils constituted a rather homogeneous group whereas outside this areano geographical zones could be distinguished. These soils were grouped based on present land use, i.e. undisturbed soils, public parks, wasteland (mainly former industrial areas), and roadside soils. The city centre and wasteland soils generally hadenhanced heavy metal concentrations to at least 30 cm depth compared to park soils outside the city centre and rural (arable)soils in the region, which were used to estimate background levels. For example, the mean Hg concentration was 0.9 (max 3.3)mg kg^-1 soil at 0–5 cm and 1.0 (max 2.9) at 30 cm depth in the city centre soils, while the background level was 0,04 mg kg^-1. Corresponding values for Pb were 104 (max 444) and135 (max 339) mg kg^-1, at 0–5 and 30 cm, respectively, while the background level was 17 mg kg^-1.The average soil pools (0–30 cm depth) of Cu, Pb and Zn were 21,38 and 58 g m^-2 respectively, which for Pb was 3–4 timeshigher and for Cu and Zn 1.5–2 times higher than the backgroundlevel. The total amount of accumulated metals (down to 30 cm)in the city centre soils (4.5^*10 ⁶ m² public gardens and green areas) was estimated at 80, 1.1, 120 and 40 t for Cu, Hg, Pb and Zn, respectively. The study showed (1) thatfrom a metal contamination point of view, more homogeneous soilgroups were obtained based on present land use than on geographicdistance to the city centre, (2) the importance of establishing a background level in order to quantify the degree of contamination, and (3) soil samples has to be taken below the surface layer (and deeper than 30 cm) in order to quantify theaccumulated metal pools in urban soils.     

Effect of Coconut, Sisal and Jute Fibers on the Properties of Starch/Gluten/Glycerol Matrix

Coconut, sisal and jute fibers were added as reinforcement materials in a biodegradable polymer matrix comprised of starch/gluten/glycerol. The content of fibers used in the composites varied from 5% to 30% by weight of the total polymers (starch and gluten). Materials were processed in a Haake torque rheometer (120 °C, 50 rpm) for 6 min. The mixtures obtained were molded by heat compression and further characterized. Addition of lignocellulosic fibers in the matrix decreased the water absorption at equilibrium. The diffusion coefficient decreased sharply around 5% fiber concentration, and further fiber additions caused only small variations. The thermogravimetric (TG) analysis revealed improved thermal stability of matrix upon addition of fibers. The Young’s modulus and ultimate tensile strength increased with fiber content in the matrix. The storage modulus increased with increasing fiber content, whereas tanδ curves decreased, confirming the reinforcing effect of the fibers. Morphology of the composites analyzed under the scanning electron microscope (SEM) exhibited good interfacial adhesion between the matrix and the added fibers. Matrix degraded rapidly in compost, and addition of increased amounts of coconut fiber in the matrix caused a slowdown the biodegradability of the matrix. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may be suitable.     

Quantification of Polymerisation Processes During The Oxidative Degradation of 14C-Labelled Chlorophenols

In experiments employing the lignocellulose-decaying basidiomycetes Trametes versicolor and Stropharia rugosoannulata degrading uniformly¹⁴C-labelled 2,4-dichlorophenol and pentachlorophenol, acombination of size exclusion chromatography (SEC),fractionation, and -scintillation counting wasapplied to quantify polymerisation products formed duringchlorophenol degradation. Time-dependent mass balances weregenerated by analysis of ¹⁴C in polymerisation products,CO₂, as well as monomer non-polar and polar metabolites.Approximately 30% of the chlorophenols were found to bepolymerised. A major fraction of the polymerised productscorresponded to a molecular weight range from 0.24 – 40 kDa.Only a minor fraction could be attributed to a molecularweight >40 kDa. This method proved to be useful inquantification of polymerisation products and kinetics of thepolymerisation processes, whereas UV/Vis detection ofpolymerisation products separated by SEC led to false positiveresults. The SEC-¹⁴C method could also be applied forother complex processes where polymerisation ordepolymerisation occurs (humification, degradation oflignocellulose, formation of bound residues from xenobioticssuch as polycyclic aromatic hydrocarbons or 2,4,6-trinitrotoluene) and where spectrophotometric determinationsare difficult or impossible.     

The Relative Influences of Primary and Secondary Particulates to Urban Air Quality in the United Kingdom

This study uses a combination of data from U.K. monitoringstations and from modelling undertaken with the U.K.Meteorological Office's NAME Model to investigate therelative influences of primary and secondary particulateson total PM₁₀ levels at sites in the United Kingdom. Co-located PM₁₀ and sulphate aerosol measurementsindicate that sulphate has a disproportionately largeinfluence on the variation of PM₁₀ levels incomparison to its contribution to their total mass.Comparisons of measured PM₁₀ at urban centre, roadsideand rural sites suggest that local primary sources havevery little influence on daily mean levels. NAME has beenused to model both primary particles and sulphate aerosolfrom sources across the whole of Europe. The discrepanciesbetween modelled and observed PM₁₀ suggest that coarseparticles, such as windblown dust and resuspended roaddust,may comprise a very large, if not dominant, proportion ofobserved PM₁₀ levels. The apparently minor role ofprimary particles (especially locally-sourced ones) raisesa number of issues regarding the suitability of current U.K.and European legislation to addressing the particle problem.     

Changes in Extractability of Cr and Pb in a Polycontaminated Soil After Bioaugmentation With Microbial Producers of Biosurfactants, Organic Acids and Siderophores

Partly because of the low bioavailability of metals, the soil cleaning-up using phytoremediation is usually time-consuming. In order to enhance the amount of metals at the plant's disposal, the soil bioaugmentation coupled together with phytoextraction is an emerging technology. In this preliminary work, two agricultural soils which mainly differed in their Cr, Hg and Pb contents (LC, low-contaminated soil; HC, high-contaminated soil) were bioaugmented in laboratory conditions by either bacterial (Bacillus subtilis, Pseudomonas aeruginosa, Pseudomonas fluorescens or Ralstonia metallidurans) or fungal inocula (Aspergillus niger or Penicillium simplicissimum) and incubated during three weeks. The LC soil pots bioaugmented with A. niger and P. aeruginosa contained higher concentrations of Cr (0.08 and 0.25 mg.kg⁻¹ dw soil) and Pb (0.25 and 0.3 mg.kg⁻¹ dw soil) in the exchangeable fraction F1 (extraction with MgCl₂) by comparison with the non-bioaugmented soil where neither Cr nor Pb was detected. Conversely, immobilization of Cr and Pb in the soil were observed with the other microorganisms. The soil bioaugmentation not only modified the metal speciation for the most easily extractable fractions but also modified the distribution of metals in the other fractions, to a lesser extent nevertheless. The difference in microbial concentrations between the bioaugmented or not HC soils reached up to 1.8 log units. Thus the microorganisms that we chose for the soil bioaugmentation were competitive towards the indigenous microflora. The PCA analysis showed close positive relationships between the microorganisms which potentially produced siderophores in the soil and the amount of Cr and Pb in the fraction F1.