负载氧化镧的活性炭还原NO的研究

稀土金属具有一些特殊的性能,这使得其对碳质材料还原NO的反应可能表现出特殊的催化效果,而此方面的研究没有报道.为了研究稀土金属对活性炭还原NO反应的催化效果,采用浸渍法制备了负载氧化镧的活性炭颗粒(La/C),并在无氧的固定床反应器中进行了程序升温反应和等温反应,考察了气体流量、NO的入口浓度、反应温度和氧化镧负载量对反应活性的影响,同时对反应机理和动力学进行了初步探讨.研究结果表明负载氧化镧的活性炭还原NO的反应是一级反应.由于炭表面3%(质量分数)的氧化镧的存在,C-NO反应的起始反应温度从500 ℃降低到300 ℃,反应活性大大提高,反应活化能从88.95 kJ/mol降低到51.05 kJ/mol.氧化镧的负载量对反应活性有重要影响,但负载量的大量增加对反应活性的提高效果甚微,最佳负载量为1.5%.La/C体系在反应中较稳定,而反应温度的升高对其稳定性不利.     

Estimation of surface area of montmorillonite by ethylene oxide chain adsorption

This study investigates the feasibility of using ethylene oxide chain adsorption to determine the surface area of an expandable clay, montmorillonite. Experimental results indicate that high molecular weight poly(ethylene oxide) or nonionic surfactant with long ethylene oxide chain should be used to provide reasonable estimations for monolayer capacity. The method has advantages over Brunauer, Emmett, and Teller method in that it is readily applicable to a wide range of areas, particularly to 2:1 layer silicates under aqueous conditions.     

铁黄生产中废水处理与废渣的回收利用

介绍了氧化铁黄生产中的废水治理情况，同时其产生的废渣可回收利用。经过治理产生的环境、经济和社会效益显著。     

Mitigation of methane and nitrous oxide emissions from drained irrigated rice fields

One of the important cultural practices that affect methane and nitrous oxide emissions from tropical rice plantations is the water drainage system. While drainage can reduce methane emissions, it can also increase nitrous oxide emissions, as well as reduce yields. In this experiment, four different water drainage systems were compared in a rice field in central Thailand including: (1) continuous flooding, (2) mid-season drainage, (3) multiple drainage and (4) a local method (drainage was done according to local cultural practice) in order to find a system of drainage that would optimize yields while simultaneously limiting methane and nitrous oxide emissions. Methane and nitrous oxide emission were observed and compared with rice yield and physical changes of rice plants. It was found that drainage during the flowering period could reduce methane emission. Interestingly, nitrous oxide emission was related to number of drain days rather than the frequency of draining. Fewer drain days can help reduce nitrous oxide emission. The mid-season drainage and the multiple drainage, with 6.9% and 11.4% reduction in rice yield, respectively, had an average methane emission per crop 27% and 35% lower when compared to the local method. Draining with fewer drain days during the flowering period was recommended as a compromise between emissions and yield. The field drainage can be used as an option to reduce methane and nitrous oxide emissions from rice fields with acceptable yield reduction. Mid-season drainage during the rice flowering period, with a shortened drainage period (3 days), is suggested as a compromise between the need to reduce global warming and current socio-economic realities.     

污泥膨胀形成机理及控制措施研究现状和进展

污泥膨胀现象在全球污水处理厂普遍存在,已成为制约活性污泥工艺发展的重大难题之一.本文总结了丝状细菌研究现状;重点阐述了当前引起污泥膨胀的主要机理;说明了基于这些机理的选择器控制理论;给出了主要的选择器类型.对当前关于污泥膨胀的研究进展和方向,分别从微生物和数学模型2个方面进行了讨论,最后,提出了一系列亟待解决的问题.     

一种新型吸附材料的除磷性能研究

针对水体富营养化的磷，采用吸附法进行处理，制备出一种新型的除磷吸附剂，对水中磷酸盐的吸附性能进行了研究，结果表明，该吸附剂对磷酸盐的吸附速率很高，在酸性条件下，其最大吸附容量为34mg／g。当溶液pH值在1～3范围内，含磷浓度为50mg／L，吸附剂投加量为200mg，接触时间为2h，磷酸盐的去除效率可达98％以上；再生后的吸附剂容量变化不大，是一种具有较高应用价值的新型材料。     

黄钠铁矾渣制备透明氧化铁黄的研究

研究了以黄钠铁矾渣为原料,采用滴加法制备透明铁黄的工艺条件,讨论了亚铁浓度、温度、通气量、搅拌速度及添加剂用量等因素对铁黄制备的影响.用XRD和TEM对产品进行表征.结果表明,铁黄粒子呈针状;长轴为95～125 nm,短轴为18～25 nm;无团聚现象,单分散性好.     

Nitrous oxide emissions from tundra soil and snowpack in the maritime Antarctic

The nitrous oxide emissions were measured at three tundra sites and one snowpack on the Fildes Peninsula in the maritime Antarctic in the summertime of 2002. The average fluxes at two normal tundra sites were 1.1 ± 2.2 and 0.6 ± 1.7 μg N₂O m⁻² h⁻¹, respectively. The average flux from tundra soil site with penguin dropping addition was 3.7 ± 2.0 μg N₂O m⁻² h⁻¹, 3–6 times those from the normal tundra soils, suggesting that the deposition of fresh droppings enhanced N₂O emissions during penguin breeding period. The summer precipitation had an important effect on N₂O emissions; the flux decreased when heavy precipitation occurred. The diurnal cycle of the N₂O fluxes from Antarctic tundra soils was not obtained due to local fluky weather conditions. The N₂O fluxes through four snowpack sites were obtained by the vertical N₂O concentration gradient and their average fluxes were 0.94, 1.36, 0.81 and 0.85 μg N₂O m⁻² h⁻¹, respectively. The tundra soils under snowpack emitted N₂O in the maritime Antarctic and increased local atmospheric N₂O concentrations; therefore these fluxes could constitute an important part of the annual N₂O budget for Antarctic tundra ecosystem.     

脉冲电晕低温等离子体提高一氧化氮氧化效率的实验研究

提高一氧化氮（NO）的氧化效率对于提高生物法处理该类废气的净化效率具有重要意义。实验研究了低温等离子体在脉冲电晕条件下氧化废气中NO的过程，考察了不同峰值电压、氧气含量、气体停留时间和添加有机物等因素对提高NO氧化效率的影响。结果表明：低温等离子法可有效地提高NO的氧化效率，主要产物为NO₂；室温条件下，当进气NO浓度590 mg/m³、脉冲频率50 Hz时，增大峰值电压、气体停留时间和进气中的氧气含量可提高NO的氧化效率；在最适峰值电压15 kV，气体停留时间5 s时，NO氧化效率为20%；在进气NO中添加甲苯、乙醇后，NO氧化效率可增加至30%以上，甲苯的效果要好于乙醇。     

Cu/ZnO-RGO的抗菌性能及应用

采用溶胶-凝胶法制备铜锌复合氧化物（Cu/ZnO）,并将Cu/ZnO纳米粒子负载到还原氧化石墨烯（RGO）表面制备Cu/ZnO-RGO复合材料.对Cu/ZnO-RGO复合材料进行表征分析及抗菌性能考察,结果表明,Cu/ZnO纳米粒子成功负载在RGO表面,负载前后Cu/ZnO纳米粒子形态不发生改变,复合材料纯度较高.Cu/ZnO-RGO复合材料对大肠杆菌与金黄色葡萄球菌均有着优异的抗菌性能,可以破坏细菌细胞膜,导致细菌内容物流出,延长细菌进入对数生长期所需的时间.当RGO质量分数为15%?Cu/ZnO-RGO复合材料使用量为120μg/mL时,在循环冷却水系统中作用2h即可拥有96.76%的抗菌率.