Fe2O3-Cr2O3/TiO2系列催化剂的结构和脱硝性能

研究以纳米TiO2为载体,浸渍负载过渡金属氧化物,以CO为还原剂的脱硝催化剂的脱硝性能。实验中以计算量的Ni(NO3)2和Fe(NO3)3混合溶液浸渍纳米TiO2粉末,室温下搅拌30 min至混合均匀,放入旋转蒸发器中,70℃下至水分蒸干为止;所得粉末在550℃下、空气气氛中焙烧4 h即得所需催化剂。用以上方法分别制备2%Fe2O3-10%Cr2O3/TiO2、4%Fe2O3-8%Cr2O3/TiO2、6%Fe2O3-6%Cr2O3/TiO2、8%Fe2O3-4%Cr2O3/TiO2与10%Fe2O3-2%Cr2O3/TiO2等5种催化剂样品。实验结果表明,制备的催化剂具有较好的结构,分散较为均匀。对于CO+NO反应,Fe2O3-Cr2O3/TiO2系列催化剂具有较好的催化活性,NO的转化率都达到了100%。其中,10%Fe2O3-2%Cr2O3/TiO2样品具有最好的低温活性,H2-TPR结果表明,这是由于10%Fe2O3-2%Cr2O3/TiO2催化剂更易于被CO预还原。     

光催化过程中羟基自由基的产生与效能

采用异丙醇淬灭的方法考察了羟基自由基在光催化氧化酸性橙II过程中的产生和效能,研究了TiO2(P-25)的浓度、异丙醇的用量、酸性橙II的初始浓度、初始pH条件和天然共存离子对羟基自由基贡献率的影响。结果表明,在TiO2(P-25)浓度提高时羟基自由基的贡献率逐步提高并稳定在77.6%,异丙醇的投加量对羟基自由基的贡献率影响不大,酸性橙II初始浓度的提高则使羟基自由基的贡献率降低。在中性pH条件下羟基自由基的贡献率最高,酸性或碱性条件下较低。天然共存离子中HCO3-对羟基自由基的淬灭效应最强,F-的淬灭效应最弱。     

某钢厂烧结烟气脱硫系统滤袋失效原因分析

分析了聚苯硫醚自身特性,从而了解目前烧结烟气脱硫系统袋式除尘器中选择其作为滤料的原因。并就目前某钢厂烧结烟气脱硫系统实际发生的滤袋失效问题,通过扫描电镜、EDS能谱分析及烧失量实验对滤袋进行分析,发现材料中混入的玻璃纤维是造成其失效的主要原因,为今后实际工程中滤袋的选择提供依据,从而尽量减少不必要的损失,确保烟气脱硫项目的正常运行。     

生物膜填料塔净化模拟烟气和电厂烟气中SO2和NOx的对比实验

对生物膜填料塔对模拟烟气和电厂烟气的净化效果进行了实验研究。实验对比分析了在相同的实验条件下生物膜填料塔对不同烟气中SO2和NOx的净化效率。实验结果表明,在循环液温度在24～35℃、空床停留时间（EBRT）为60s、喷淋量为8～10L／h、脱硫塔的pH为0．8～1．5、脱氮塔的pH为7．5～8．0的条件下,生物膜填料塔对模拟烟气和电厂烟气中SO2的净化效率都很高,但模拟烟气条件下的总脱氮率的平均值为80％,而在电厂烟气条件下只有35％。经分析认为,脱氮率产生差异的主要原因是电厂烟气中杂质的影响,以及烟气中氧气含量的不同,同时因为生长条件不同从而驯化出的微生物群体组成也不同。     

交通发展对安徽省旅游业的影响研究

交通要素是沟通旅游需求、旅游供给的纽带和桥梁,旅游发展与交通条件密切相关。对安徽省交通发展进行了系统梳理,从游客、旅游资源、旅游企业、旅游产品(线路)组合、旅游空间结构等5个方面分析了交通发展对安徽省旅游业的影响。在剖析存在问题的基础上,提出了交通进一步促进安徽省旅游发展的若干建议和对策。     

Influence of regional development policies and clean technology adoption on future air pollution exposure

Future air pollution emissions in the year 2030 were estimated for the San Joaquin Valley (SJV) in central California using a combined system of land use, mobile, off-road, stationary, area, and biogenic emissions models. Four scenarios were developed that use different assumptions about the density of development and level of investment in transportation infrastructure to accommodate the expected doubling of the SJV population in the next 20 years. Scenario 1 reflects current land-use patterns and infrastructure while scenario 2 encouraged compact urban footprints including redevelopment of existing urban centers and investments in transit. Scenario 3 allowed sprawling development in the SJV with reduced population density in existing urban centers and construction of all planned freeways. Scenario 4 followed currently adopted land use and transportation plans for the SJV. The air quality resulting from these urban development scenarios was evaluated using meteorology from a winter stagnation event that occurred on December 15th, 2000 to January 7th 2001. Predicted base-case PM2.5 mass concentrations within the region exceeded 35 μg m^?3 over the 22-day episode. Compact growth reduced the PM2.5 concentrations by ～1 μg m^?3 relative to the base-case over most of the SJV with the exception of increases (～1 μg m^?3) in urban centers driven by increased concentrations of elemental carbon (EC) and organic carbon (OC). Low-density development increased the PM2.5 concentrations by 1–4 μg m^?3 over most of the region, with decreases (0.5–2 μg m^?3) around urban areas. Population-weighted average PM2.5 concentrations were very similar for all development scenarios ranging between 16 and 17.4 μg m^?3. Exposure to primary PM components such as EC and OC increased 10–15% for high density development scenarios and decreased by 11–19% for low-density scenarios. Patterns for secondary PM components such as nitrate and ammonium ion were almost exactly reversed, with a 10% increase under low-density development and a 5% decrease under high density development. The increased human exposure to primary pollutants such as EC and OC could be predicted using a simplified analysis of population-weighted primary emissions. Regional planning agencies should develop thresholds of population-weighted primary emissions exposure to guide the development of growth plans. This metric will allow them to actively reduce the potential negative impacts of compact growth while preserving the benefits.     

浅谈大学生社会实践活动的项目化管理

结合中国环境管理干部学院"千名学生绿色行"活动的项目化管理的具体组织和实践情况,在实际工作中探索大学生社会实践活动项目化管理的科学性和有效性,将项目化管理模式应用于大学生实践活动的管理中,最大限度地利用现有的学生活动资源、规范管理行为、降低管理成本、提高工作效率,实现培养大学生综合素质和创新能力的目的。     

秦皇岛市天然矿泉水水质特征及开发利用前景研究

秦皇岛市天然矿泉水主要赋存在早太古代的花岗岩和变质岩的构造裂隙与风化裂隙之中,有锶、偏硅酸、锶及偏硅酸、锶溴及偏硅酸等4种类型。矿泉水水源地数量较多,水质优良,但开采程度较低,开发利用前景广阔。     

Functional groups of marine ciliated protozoa and their relationships to water quality

Ciliated protozoa (ciliates) play important ecological roles in coastal waters, especially regarding their interaction with environmental parameters. In order to increase our knowledge and understanding on the functional structure of ciliate communities and their relationships to environmental conditions in marine ecosystems, a 12-month study was carried out in a semi-enclosed bay in northern China. Samples were collected biweekly at five sampling stations with differing levels of pollution/eutrophication, giving a total of 120 samples. Thirteen functional groups of ciliates (A–M) were defined based on their specific spatio-temporal distribution and relationships to physico-chemical parameters. Six of these groups (H–M) were the primary contributors to the ciliate communities in the polluted/eutrophic areas, whereas the other seven groups (A–G) dominated the communities in less polluted areas. Six groups (A, D, G, H, I and K) dominated during the warm seasons (summer and autumn), with the other seven (B, C, E, F, J, L and M) dominating in the cold seasons (spring and winter). Of these, groups B (mainly aloricate ciliates), I (aloricate ciliates) and L (mainly loricate tintinnids) were the primary contributors to the communities. It was also shown that aloricate ciliates and tintinnids represented different roles in structuring and functioning of the communities. The results suggest that the ciliate communities may be constructed by several functional groups in response to the environmental conditions. Thus, we conclude that these functional groups might be potentially useful bioindicators for bioassessment and conservation in marine habitats.     

Phosphine in paddy fields and the effects of environmental factors

Ambient levels of phosphine (PH₃) in the air, phosphine emission fluxes from paddy fields and rice plants, and the distribution of matrix-bound phosphine (MBP) in paddy soils were investigated throughout the growing stages of rice. The relationships between MBP and environmental factors were analyzed to identify the principal factors determining the distribution of MBP. The phosphine ambient levels ranged from 2.368 ± 0.6060 ng m⁻³ to 24.83 ± 6.529 ng m⁻³ and averaged 14.25 ± 4.547 ng m⁻³. The highest phosphine emission flux was 22.54 ± 3.897 ng (m² h)⁻¹, the lowest flux was 7.64 ± 4.83 ng (m² h)⁻¹, and the average flux was 14.17 ± 4.977 ng (m² h)⁻¹. Rice plants transport a significant portion of the phosphine emitted from the paddy fields. The highest contribution rate of rice plants to the phosphine emission fluxes reached 73.73% and the average contribution was 43.00%. The average MBP content of 111.6 ng kg⁻¹fluctuated significantly in different stages of rice growth and initially increased then decreased with increasing depth. The peak MBP content in each growth stage occurred approximately 10 cm under the surface of paddy soils. Pearson correlation analyses and stepwise multiple regression analysis showed that soil temperature (Ts), acid phosphatase (ACP) and total phosphorus (TP) were the principal environmental factors, with correlative rankings of Ts > ACP > TP.