抚仙湖硅藻群落的时空变化特征及其与水环境的关系

抚仙湖是我国重要的深水型淡水湖泊且水体水质总体处于I类水平,近年来在流域开发、全球变暖等影响下其生态环境功能呈现退化的趋势,需要对湖泊生物的群落组成、分布模式及其驱动因子进行系统评价.本研究于2015年选取抚仙湖的南、中、北湖区共3个采样点开展了表层水体硅藻群落和水环境特征的逐月分析.样品中共发现硅藻31个属、166个种且以浮游类型为主,其中云南特有硅藻种Cyclotella rhomboideo-elliptica基本消失.硅藻群落结构的逐月变化在3个采样点中均呈现明显的季节演替特征,其中1、2月优势种主要为Fragilaria crotonensis,3月优势种为Aulacoseira granulata,4月C.ocellata与F.crotonensis同为优势种,而在其余月硅藻群落结构较为单一且优势物种皆为C.ocellata(相对丰度占~80%).而空间尺度上,硅藻优势属种分布和群落结构具有较高的一致性.主成分分析显示,不同湖区的硅藻群落结构组成和水体环境在时间尺度上存在较大差异,而在空间尺度上差异较小;冗余分析和变差分解等分析结果进一步表明,影响群落结构时空变化的主要驱动因子是气象与物理因子(包括水温、风速和透明度),共解释了硅藻群落变率的27.6%,表明了该深水湖泊水体热力分层的厚度与持续时间是影响硅藻群落构建的重要过程.同时,湖泊营养水平与水体离子浓度也对硅藻群落结构产生了明显影响,分别解释了硅藻群落变率的21.2%和9.4%.因此,持续的区域变暖和流域开发明显影响了抚仙湖的生物群落构建与生态系统健康,对抚仙湖的生态保护不仅需要控制营养盐等流域污染物的输入,同时应该积极应对气候变化的长期影响.     

Ce掺杂改性Ni-Al-Ox催化剂CO-NO反应性能

通过尿素法制备了一系列Ce掺杂改性的Ni-Al-O_x复合氧化物催化剂,并研究了催化剂的CO-NO反应性能.活性测试结果表明,Ni-Al-Ce-O_x的催化活性明显优于Ni-Al-O_x,且活性随着Ce含量的增加而提高.当Ce的掺杂量为20%时,250℃条件下,NO转化率高达95%以上,同时催化剂具有良好的抗H₂O性能.XRD和Raman分析表明,Ce掺杂Ni-Al-O_x催化剂促进了氧空位产生.而XPS结果显示,氧空位随着Ce含量的增加而增加.H₂-TPR结果表明,Ce的掺杂使催化剂的氧化还原性能增强.结合NO-TPD和FTIR的表征结果,进一步发现Ce的加入使表面氧难以将NO氧化成硝酸盐,有利于NO在Ce的氧空位上分解为N₂或N₂O,促进CO-NO反应的进行.     

钻井现场安全监督系统研发及应用

基于钻井现场安全监督在管控钻井作业风险中的重要性和当前钻井安全监督能力方面的缺陷,采用信息化手段,提出了钻井现场安全监督系统整体架构设计和数据库建设思路,介绍了系统功能和应用情况,结果表明:该系统能够显著提高钻井现场监督工作质量,实现钻井现场安全事故的有效控制。     

Preliminary investigation of phosphorus adsorption onto two types of iron oxide-organic matter complexes

Iron oxide(FeO)coated by natural organic matter(NOM)is ubiquitous.The associations of minerals with organic matter(OM)significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients(e.g.,phosphorus(P)).In this study,ferrihydrite/goethite-humic acid(FH/GE–HA)complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity(Q_(max))decreased in the order of FH(22.17 mg/g)FH-HA(5.43 mg/g)GE(4.67 mg/g)GE-HA(3.27 mg/g).After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.     

Polycyclic aromatic hydrocarbon concentrations, compositions, sources, and associated carcinogenic risks to humans in farmland soils and riverine sediments from Guiyu, China

The concentrations of 16 priority polycyclic aromatic hydrocarbons(PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste(EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments.The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources,but the PAHs in the sediments were derived from both combustion and petroleum sources.     

Chemical characteristics of fine particles and their impact on visibility impairment in Shanghai based on a 1-year period observation

In this work, a one-year observation focusing on high time resolution characteristics of components in fine particles was conducted at an urban site in Shanghai. Contributions of different components on visibility impairment were also studied. Our research indicates that the major components of PM_2.5 in Shanghai are water-soluble inorganic ions and carbonaceous aerosol, accounting for about 60% and 30% respectively. Higher concentrations of sulfate (SO₄²⁻) and organic carbon (OC) in PM_2.5 occurred in fall and summer, while higher concentrations of nitrate (NO₃⁻) were observed in winter and spring. The mass concentrations of Cl⁻ and K⁺ were higher in winter. Moreover, NO₃⁻ increased significantly during PM_2.5 pollution episodes. The high values observed for the sulfate oxidizing rate (SOR), nitrate oxidizing rate (NOR) and secondary organic carbon (SOC) in OC indicate that photochemical reactions were quite active in Shanghai. The IMPROVE (Interagency Monitoring of Protected Visual Environments) formula was used in this study to investigate the contributions of individual PM_2.5 chemical components to the light extinction efficient in Shanghai. Both NH₄NO₃ and (NH₄)₂SO₄ had close relationships with visibility impairment in Shanghai. Our results show that the reduction of anthropogenic SO₂, NO_x and NH₃ would have a significant effect on the improvement of air quality and visibility in Shanghai.     

固定床活性炭干法烟气脱硫过程的模拟研究

采用流程模拟软件对固定床活性炭干法烟气脱硫过程进行模拟,并用已公开发表的文献实验数据进行了模型验证。模型验证结果与文献值吻合较好。利用该模型对活性炭干法烟气脱硫过程进行模拟研究,探讨了脱硫过程中床层高度、进口烟气中SO_2质量浓度、吸附温度等工艺参数对SO_2脱除率的影响。模拟结果表明:随床层高度增加,SO_2脱除率提高;随进口烟气中SO_2质量浓度增加,SO_2脱除率提高;在吸附温度为100~160℃的范围内,随吸附温度升高,SO_2脱除率逐渐下降。     

石油开采区域生态环境质量综合评价研究

石油开采在规模不断扩张的同时,也造成了大面积的采区环境污染,严重降低了生态环境质量.为探索石油开采区域生态环境质量综合评价的有效方法,通过对石油开采区域生态环境质量及综合评价现状的分析,精选指标构建了石油开采区域生态环境质量的综合评价指标体系,利用专家调查法确定了各评价指标的相对权值,并构建了石油开采区域生态环境质量模糊综合评价模型,选择胜利油田某采区进行了综合评价的应用研究,对模糊综合评价模型的有效性进行了验证.     

基于GMM模型的山东省能源消费主要驱动因素分析研究

山东省是中国的经济大省和人口大省,更是能源消费最大的省份.本文运用广义矩阵模型(GMM)对2000-2014年间山东省能源消费的驱动因素进行分析,结果表明:山东省能源消费总量呈不断上升趋势,各驱动因素中人口规模影响最大,其次为城市化水平和第二产业比重,对外贸易与GDP增长影响较小且都为负效应.因此,依靠相关法律法规合理控制人口增长和城市化进程有利于减少能源消费水平.本文根据最新统计数据深入研究山东省能源消费的主要驱动.     

火电厂烟气脱硫设施工况监控系统研究与应用

本文介绍了火电厂烟气脱硫设施工况监控系统,研究了系统关键技术。通过建立数学模型,对火电厂烟气脱硫设施主要参数进行数据有效性范围校验、关联度判断、逻辑判断,实现对脱硫设施运行异常状态的报警,最后通过实例说明了工况监控系统在环境监管中的应用。