以废纸为原料制备煤尘抑制剂的合成及应用

采用碱化、醚化法制备了以废纸为原料的煤尘抑制剂,借助FTIR、SEM、TG-DTA及XRF等手段对合成物进行了表征,并将其用于抑制煤尘进行性能测试。结果表明,羧甲基纤维素的取代度为0.69;选用羧甲基纤维素含量为0.5g/mL的煤尘抑制剂进行应用实验,效果最佳。9 h内,喷洒含有羧甲基纤维素的煤尘抑制剂的煤样表面已经结壳,抗七级风,抑尘率在130 h都可保持在99%以上。在较高温燃烧条件下,煤尘抑制剂以H2O和CO2的形式失去,不会产生有害物质。     

膨润土接枝丙烯酸高吸水性树脂的抑尘性能研究

在微波辐射下制备了膨润土接枝丙烯酸高吸水性树脂(SAP)(一种加入聚乙烯醇(PVA),另一种不加入PVA)。结果表明:(1)红外光谱图表明,PVA与聚合网络形成了半互穿网络结构;X射线衍射图表明,膨润土与PVA、丙烯酸形成了具有无定形结构的复合产物。(2)不论是沙土堆还是尘土堆,喷洒膨润土接枝丙烯酸SAP溶液的抑尘效果明显比喷洒自来水好;喷洒膨润土接枝丙烯酸SAP溶液的尘土堆的抑尘效果好于沙土堆。(3)在温度为15℃时,考虑到节约成本的问题,首选不加入PVA的膨润土接枝丙烯酸SAP做抑尘剂;在温度为45℃时,加入PVA的膨润土接枝丙烯酸SAP适合做抑尘剂。(4)膨润土接枝丙烯酸SAP浓度越高,其耐蒸发性越高。     

输煤皮带转载点密闭罩流场模拟与结构优化

为了研究输煤皮带转载点密闭罩内流场对吸尘效果的影响,采用Fluent软件对某转载点密闭罩内气固两相流动情况进行了数值模拟。通过气流分布和煤尘浓度分布的分析,发现溜槽转折处较大的气流偏转会增加煤尘起尘量和导致局部煤尘积聚,吸尘罩的开口角度对吸尘效果也有较大影响。为了疏导气流并加强吸尘效果,提出了溜槽转折处和吸尘罩的结构优化设计方案。研究表明,改进后气流分布更加均匀,吸尘效果有所提高,从而为转载点密闭罩的优化设计提供了参考。     

The effects of surfactants on adhesion,spreading, and retention of herbicide droplet on the surface of the leaves and seeds

Droplet adhesion, spreading, and retention on leaf and seed surfaces are studied in the presence of surfactants for successful formulation of a herbicide whereby efficient coverage, less wastage, and environment protection are achieved. Cationic, anionic, and nonionic surfactants, e.g., HTAB, SDBS, and tergitol, were added to water and the static contact angle of water droplet was measured on cauliflower, cabbage, spinach leaves, French bean, wheat, and Bengal gram seeds. Droplet adhesion, spreading, and retention were analysed in terms of static contact angle and physical properties of the system. The presence of a small quantity (0.1 wt.%) of tergitol in water increased the adhesion, spreading, and retention of droplet on all leaf and seed surfaces tested. Tergitol, a nonionic surfactant, is likely to be adsorbed more than the ionic surfactants HTAB and SDBS at the water/leaf (or seed)/air interface since plant leaves and seeds are nonionic in nature. The addition of 0.1% wt. of tergitol to a common herbicide, derosal, increases the adhesion, spreading, and retention of derosal on leaf and seed surfaces, consequently, efficient coverage and minimum wastage are attained.     

双循环多级水幕吸收塔烟气除尘脱硫性能研究

以改进后的双循环多级水幕塔对烟气进行除尘脱硫性能的研究，利用双循环不同pH值控制的优点和多级水幕的效果，增加气液接触面积和传质动力，提高SO₂吸收效果。在正交实验的最佳运行工况基础上，实验从烟气流量、上下两段pH、L/G和SO₂进气浓度等方面进行单因素研究。结果表明，除尘效率维持在98%以上，进气SO₂浓度在5 000 mg/m³以下时，脱硫率在93%以上。上段pH值为6、下段pH值为5、L/G在15左右的脱硫效率和运行工况最佳，无结垢现象发生。改进后的吸收塔具有良好的应用前景，实验结果对于现场脱硫设备的调试和运行有很好的参考价值。     

Study on photocatalytic degradation of gaseous dichloromethane using pure and iron ion-doped TiO2 prepared by the sol-gel method

The synthesis of TiO₂ and Fe–TiO₂ by sol–gel method is demonstrated and characterized. The characterization of TiO₂ and Fe–TiO₂ is performed with instruments, including TGA/DTA, FTIR, UV–Vis, N₂ adsorption and SEM. Dichloromethane is used for the photocatalytic activity test. From the results of dichloromethane photocatalyitc degradation, the calcined temperature of TiO₂ and the presence of water vapor influence the photocatalytic activity. The optimum doping amount of iron ions is 0.005 mol%, and this can enhance the photocatalytic activity, while too great an amount will make the iron ions become recombination centers for the electron–hole pairs and reduce the photocatalytic activity. UV–Vis diffuse reflectance spectra of Fe–TiO₂ show an increase in absorbency in the visible light region with the increase in iron ions doping concentration The intermediate of dichloromethane photodegradation includes CHCl₃, CCl₄, CH₂Cl₂ and COCl₂. The presence of iron ions may reduce the adsorption of Cl element on the surface of the photocatalyst.     

利用复介电常数和BPAT神经网络进行环境监测的可行性研究

土壤中的污染物成分复杂，其含量与复介电常数之间具有很强的非线性关系。以土壤样品复介电常数的实部、虚部分别作为输入，以其含水率、体密度和所含6种已知离子的浓度分别作为输出，建立BP人工神经网络。把吉泰兰地区的土壤样品数据分为训练样本集和检验样本集，网络训练后，其学习效果显示模型的性能很好，检验样本的预测结果也与实测值较好吻合，说明利用复介电常数和BP人工神经网络进行环境监测是一种好的方法。     

The sorption of heavy metal species by sediments in soakaways receiving urban road runoff

Infiltration facilities are designed for both the retention of non-point pollutants and the replenishment of groundwater in urban areas. In this study, sorption tests were conducted to evaluate the speciation of heavy metals and their behaviour in infiltration facilities receiving urban road runoff containing high DOC concentrations and stable heavy metal organic complexes. Road dust and three soakaway sediments were collected from heavy traffic areas and a residential area with an infiltration-type sewerage system in Tokyo, Japan. Sequential multiple batch tests were conducted by adding prepared road dust leachate (artificial road runoff) or deionised water to soakaway sediment to obtain soakaway sediment leachate (artificial percolating water from soakaway sediment), which mimicked the sorption by sediments in soakaways receiving urban road runoff. Heavy metal speciation was assessed by means of a combination of anion-exchange resin measurements and MINTEQA2 model calculations, and further validated by chelating resin measurements. In road dust leachates and soakaway sediment leachates, Cu predominantly existed as organic complexes and carbonates, whereas most Mn, Zn and Cd were found to exist in the form of free ions and carbonate complexes. Stable organic complexes of Cu in road dust leachates were strongly adsorbed by soakaway sediments despite the limited adsorption of DOC. On the other hand, desorption of free Mn, Zn and Cd ions from the sediment receiving road dust leachates was observed, indicating that heavy metals such as Mn, Zn and Cd may ultimately reach groundwater as free ions.     

矸石基X型分子筛对水中Co2+、Cu2+、Cd2+和Cr3+的去除

以煤矸石为原料,采用碱熔后水热合成法制备X型分子筛并进行XRD、SEM、BET和Zeta电位分析。研究其对水中Co2+、Cu2+、Cd2+和Cr3+4种离子的吸附性能,包括吸附等温线、吸附动力学以及初始金属离子浓度、pH值对吸附性能的影响。所合成的矸石基X型分子筛的BET比表面积为676.02 m2/g,微孔孔容为0.263 cm3/g。吸附实验表明,矸石基X型分子筛能有效去除上述4种离子,同时实现煤矸石的资源化和金属离子的去除。4种离子的平衡吸附量均随初始浓度的增大而增大,相同条件下平衡吸附量的大小顺序为Cd2+>Cr3+>Cu2+>Co2+。准二级动力学模型能很好地描述4种离子的吸附动力行为。Langmuir模型对Co2+、Cu2+和Cd2+吸附的拟合较Freundlich模型高,说明其主要表现为物理吸附过程。4种离子的吸附速率均由液膜扩散和颗粒内扩散共同控制。     

新型湿式湍流除尘器及在电厂输煤系统中的应用

介绍了针对火电厂输煤系统作业环境粉尘治理而研制开发的新型湿式湍流除尘器的设计思路、设备结构、技术特点及在电厂输煤系统的应用情况.     

新型湿式湍流除尘器及在电厂输煤系统中的应用

介绍了针对火电厂输煤系统作业环境粉尘治理而研制开发的新型湿式湍流除尘器的设计思路、设备结构、技术特点及在电厂输媒系统的应用情况。     

Unavailability of polynuclear aromatic hydrocarbons from coal particles to the eastern oyster

The accumulation by oysters of polycyclic aromatic hydrocarbons (PAH) from coal dust entering the estuarine environment has been postulated in the vicinity of coal transfer operations. Oysters Crassostrea virginica were exposed to coal dust plus 15 day leachate at concentrations of 10 mg litre(-1) and 1 mg litre(-1) coal dust for 28 days in a flow-through test system. Potential effects of the exposures were measured by comparing the uptake of PAH and the growth of the exposed animals versus control groups. Oysters sampled at 7, 14 and 28 days did not exhibit an increase in PAH body burden over control animals provided the guts were first purged of particulates. Even at the high test concentrations (10 mg litre(-1)), no effect of the exposure on shell growth was observed.     

Comparison of the physical and chemical characteristics of fine road dust at different urban sites

The size distribution and chemical components of a fine fraction (<2.5 μm) of road dust collected at urban sites in Korea (Gwangju) and Mongolia (Ulaanbaatar) where distinct urban characteristics exist were measured. A clear bimodal size distribution was observed for the resuspended fine road dust at the urban sites in Korea. The first mode peaked at 100–110 nm, and the second peak was observed at 435–570 nm. Ultrafine mode (~30 nm) was found for the fine road dust at the Mongolia site, which was significantly affected by residential coal/biomass burning. The contribution of the water-soluble ions to the fine road dust was higher at the sites in Mongolia (15.8–16.8%) than at those in Korea (1.2–4.8%). Sulfate and chloride were the most dominant ionic species for the fine road dust in Mongolia. As (arsenic) was also much higher for the Mongolian road dust than the others. The sulfate, chloride, and As mainly come from coal burning activity, suggesting that coal and biomass combustion in Mongolia during the heating season should affect the size and chemical components of the fine road dust. Cu (copper) and Zn (zinc), carbonaceous particles (organic carbon [OC] and elemental carbon [EC]) increased at sites in Korea, suggesting that the fine road dust at these sites was significantly affected by the high volume of traffic (engine emission and brake/tire wear). Our results suggest that chemical profiles for road dust specific to certain sites should be applied to more accurately apportion road dust source contributing to the ambient particulate matter.

Implications: Size and chemical characteristics of fine road dust at sites having distinct urban characteristics were examined. Residential coal and biomass burning and traffic affected physiochemical properties of the fine road dust. Different road dust profiles at different sites should be needed to determine the ambient PM2.5 sources more accurately.     

小型焦炉废气和废水处理方法

焦炉装煤和推焦烟气合用 1套收集系统。除尘废水经吸附后用于熄焦 ,熄焦水经吸附后用于湿式除尘 ,实现循环零排放。煤气洗涤水循环为废水中氨氮的处理提供了可行的方法     

贝壳粉型煤固硫剂固硫的实验及机理研究

以贝壳粉作为型煤固硫剂,用正交实验的方法研究了影响贝壳粉固硫率的主要影响因素,在高温(1 150℃)时固硫效率达到56.6%,比CaCO3的固硫率提高40%以上,具有较好的高温固硫性。分析得知,贝壳的主要成分为CaCO3,其含钙量在40%左右,贝壳中又含有较高的Na等碱金属元素以及Fe,Al和Si等。用X射线粉末衍射法分析了高温(1 150℃)型煤样生成的灰渣,分析了贝壳粉作为型煤固硫剂在高温下具有较高固硫率的机理。发现CaAlSi2O8为主的复合晶体在高温下包裹在CaSO4的表面,抑制了CaSO4的热分解从而有效地提高了固硫率。     

复合型除尘器除尘脱硫一体化工艺实验研究

试验研究了专利产品"高压静电滤槽复合型卧式除尘器"的除尘脱硫一体化工艺.试验表明,在布袋前方的末级电场中实行半干法脱硫工艺具有可行性,可达到除尘脱硫一体化目的.试验同时研究了钙硫比、脱硫灰循环率、饱和温距、喷水量和SO2浓度等对脱硫率的影响.该工艺适用于以低硫煤为燃料的锅炉进行除尘脱硫.     

复合型除尘器除尘脱硫一体化工艺实验研究

试验研究了专利产品“高压静电滤槽复合型卧式除尘器”的除尘脱硫一体化工艺。试验表明，在布袋前方的末级电场中实行半干法脱硫工艺具有可行性，可达到除尘脱硫一体化目的。试验同时研究了钙硫比、脱硫灰循环率、饱和温距、喷水量和SO2浓度等对脱硫率的影响。该工艺适用于以低硫煤为燃料的锅炉进行除尘脱硫。     

二氧化氯-接触催化氧化联合去除水中铁和锰

为了解决水体中铁锰季节性超标的问题,提出一种既能够减少化学试剂的使用又能有效去除铁锰的经济有效的方法。研究了单一方法(二氧化氯氧化法、接触催化氧化法)及两者联合对铁锰的去除效果,提出用二氧化氯氧化-锰砂过滤联合方法解决。研究表明,用ClO2氧化去除水中Fe2+的反应先发生、速率较快且效果较好,而与Mn2+反应则较慢并且不能完全转化为沉淀。单纯接触催化氧化法需要较长时间,过滤层才能达到稳定且较好的处理效果,培养过程中其除锰效果并不理想。两者联合时,利用过滤层的吸附作用去除部分铁锰,减少了氧化剂的使用。初期3个柱的除Mn2+效果都比较好,去除率均大于80%;然而采用石英砂或纤维束滤料的滤柱去除Mn2+的效果随时间变差,但采用锰砂的除锰效果在实验期间始终维持在较高水平。     

The removal of arsenate from water using iron-modified diatomite (D-Fe): isotherm and column experiments

Iron hydroxide supported onto porous diatomite (D-Fe) is a low-cost material with potential to remove arsenic from contaminated water due to its affinity for the arsenate ion. This affinity was tested under varying conditions of pH, contact time, iron content in D-Fe and the presence of competitive ions, silicate and phosphate. Batch and column experiments were conducted to derive adsorption isotherms and breakthrough behaviours (50 μg L^?1) for an initial concentration of 1,000 μg L^?1. Maximum capacity at pH 4 and 17 % iron was 18.12–40.82 mg of arsenic/g of D-Fe and at pH 4 and 10 % iron was 18.48–29.07 mg of arsenic/g of D-Fe. Adsorption decreased in the presence of phosphate and silicate ions. The difference in column adsorption behaviour between 10 % and 17 % iron was very pronounced, outweighing the impact of all other measured parameters. There was insufficient evidence of a correlation between iron content and arsenic content in isotherm experiments, suggesting that ion exchange is a negligible process occurring in arsenate adsorption using D-Fe nor is there co-precipitation of arsenate by rising iron content of the solute above saturation.     

多水源供水管网中铁释放规律

针对水源切换而引起的水质超标现象,开展了多水源联合供水条件下管网中铁释放规律的研究。分析了北方某城市2种水源(滦河水和长江水)的水质特点,利用实验模拟反应器分别研究了水源完全置换和供水分界线处水源混合区域的铁释放规律。结果表明,多水源供水管网的铁释放速率与水源水质密切相关,特别是水中含高浓度SO2-4和氯化物时会加快铁的释放。不同水源之间的频繁切换会破坏管垢表面的钝化层,使铁释放速率迅速变化,随后会有所缓解,但新的平衡的形成需要较长时间。供水分界线处的水源混合区域,由于水质的不断变化造成管垢表面很难形成稳定的钝化层,铁释放速率持续偏高,只有当长江水所占比例高达75%以上时才能得到抑制。