超重力技术新一代反应与分离工业性技术

<正>北京化工大学教育部超重力工程研究中心自20世纪80年代以来一直致力于超重力反应与分离技术的基础理论与应用技术研究。承担过国家自然科学基金、973计划、863计划、十五重大科技攻关计划、国家新材料高技术产业化示范工程项目等多项科研项目和国际合作项目。     

从水或水溶液中去除重金属及溶解钙和／或镁垢的方法

该发明涉及一种从水或水溶液中去除重金属及溶解钙和／或镁垢的方法，用于从水或水溶液中去除重金属的螯合剂或去除钙和／或镁垢的溶解剂为：γ-聚谷氨酸（γ-PGA，H型）和／或其一种或数种盐（例如：Na^＋型γ-PGA、K’型γ-PGA及NH4型γ-PGA）和／或γ-聚谷氨酸水凝胶。     

多环芳烃在西江高要段水体中的分布与分配

为了解西江流域水体中多环芳烃(PAHs)的深度和季节分布及其在溶解相和颗粒相的分配以及控制因素,分别在洪水期(2003年8月和2004年7月)和枯水期(2003年11月和2004年3月)采集了西江高要段水柱.结果表明,溶解相和颗粒相中PAHs的浓度分别为21.7~138 ng/L和40.9~664.8μg/kg;水体中PAHs的总含量(颗粒相及溶解相),洪水期大于枯水期.在溶解相中,PAHs的浓度随深度无明显规律;而在颗粒物中,PAHs的浓度都表现出相同的变化趋势,即中层水PAHs含量最高,表层水PAHs含量最低.溶解相和颗粒相中PAHs的浓度都随悬浮颗粒物的含量增加而增加.从PAHs组成特点来看,溶解相以3环的PAHs为主,而颗粒相以3~4环的PAHs为主.PAHs在颗粒相及溶解相中的分配系数(KP)不受颗粒有机碳浓度控制(R2为0.000 1~0.2),而受颗粒物浓度、及溶解有机碳浓度的共同影响(R2为0.15~0.36),尤其是溶解态的细小碳黑有机质的影响.西江高要段水体PAHs在不同季节的lgKOC值大部分超过经典平衡分配模型的上限.除了2003年11月(R2为0.000 4~0.12,p0.001)之外,其它3个季节PAHs的lgKOC与lgKOW均有较强的相关性(R2为0.29~0.91,p0.05).洪水期颗粒物的亲脂性强于枯水期.     

Effect of a seasonal di use pollution migration on natural organic matter behavior in a stratified dam reservoir

This article aims to describe the influence of di use pollution on the temporal and spatial characteristics of natural organic matter (NOM) in a stratified dam reservoir, the Daecheong Dam, on the basis of intensive observation results and the dynamic water quality simulation using CE-QUAL-W2. Turbidity is regarded as a comprehensive representation of allochothonous organic matter from di use sources in storm season because the turbidity concentration showed reasonable significance in a statistical correlation with the UV absorbance at 254 nm and total phosphorus. CE-QUAL-W2 simulation results showed good consistency with the observed data in terms of dissolved organic matter (DOM) including refractory dissolved organic carbon (RDOC) and labile DOC and also well explained the internal movement of constituents and stratification phenomenon in the reservoir. Instead turbidity and NOM were related well in the upper region of the reservoir according to flow distance, gradually as changing to dissolved form of organic matter, RDOM a ected organic matter concentration of reservoir water quality compared to turbidity. To control the increase of soluble organic matters in the dam reservoir, appropriate dam water discharge gate operation provided e ective measurement. Because of the gate operation let avoid the accumulation of organic matter within a dam reservoir by shorten of turbid regime retention time.     

长江口及其邻近水域溶解无机氮的分布变化特征

根据2004年4个航次的调查资料,研究了长江口及其邻近水域溶解无机氮的分布变化特征。结果表明,高浓度溶解无机氮集中分布在河口附近。一般来讲,近岸硝酸盐浓度上层高于下层,远岸与之相反。由于生物和化学作用的影响,亚硝酸盐和铵盐垂直断面分布较为复杂。随着长江径流量的增加与减小、冲淡水势力范围的扩大与缩小,硝酸盐季节分布随之变化,然而,亚硝酸盐春季浓度较高,铵盐冬季浓度远大于其它季节。各月DIN/PO4-P比值远高于Redfield比值。与1985~1986年相比,20余年溶解无机氮增加了2.2倍,DIN/PO4-P比值升高了1.4倍,这主要取决于溶解无机氮浓度的增加。溶解无机氮在河口的转移除了生物活动的影响外,主要受海水稀释作用的控制。     

一模两件锻造的探讨和应用

对简单锻件、截面差变化较大锻件和带落差锻件等3类锻件进行了一模两件锻造分析、计算和设计。根据3类锻件的特点,对锻造所需设备进行了吨位的计算及合理地排列,总结出了灵活运用一模两件锻造的一般规律和方法。一模两件锻造与传统的锻造工艺相比,有提高模具寿命、提高生产效率、节约生产成本等优点。     

连云港东西连岛附近海域表层溶解氧含量多年变化趋势分析

对1995年-2005年国家海洋局连云港海洋环境监测站的溶解氧等数据进行了分析,结果表明,连云港东西连岛附近海域表层溶解氧含量多年来呈现增加的趋势,同时冬季平均含量高于春季,春季高于秋季,而夏季最低;东西连岛附近海域表层溶解氧含量与表层水温呈现良好的线性负相关关系,据此相关性可以获取表层溶解氧含量的动态变化值;此外,东西连岛附近海域表层溶解氧过饱和程度在2000年之后呈加剧趋势。     

基于层次分析法的莆田市生态环境可持续发展力评价

文章以环境学、生态学、可持续发展理论为基础,通过对莆田市环境现状及社会经济进行分析,首次建立了莆田市生态环境可持续发展力指标体系。运用层次分析法确定评价指标体系中各项指标的权重,最终进行莆由市的现状生态环境可持续发展力评价及指标体系综合指数的计算验证。结果表明莆田市生态环境可持续发展能力较好,基本能够满足当地可持续发展的要求。     

Effect of carbon source on the denitrification in constructed wetlands

The ability of constructed wetlands with di erent plants in nitrate removal were investigated. The factors promoting the rates of denitrification including organic carbon, nitrate load, plants in wetlands, pH and water temperature in field were systematically investigated. The results showed that the additional carbon source (glucose) can remarkably improve the nitrate removal ability of the constructed wetland. It demonstrated that the nitrate removal rate can increase from 20% to more than 50% in summer and from 10% to 30% in winter, when the nitrate concentration was 30–40 mg/L, the retention time was 24 h and 25 mg/L dissolved organic carbon (DOC) was ploughed into the constructed wetland. However, the nitrite in the constructed wetland accumulated a little with the supply of the additional carbon source in summer and winter, and it increased from 0.15 to 2 mg/L in the e uent. It was also found that the abilities of plant in adjusting pH and temperature can result in an increase of denitrification in wetlands. The seasonal change may also impact the denitrification.     

小球藻来源溶解有机质的光化学降解特性

利用三维荧光光谱-平行因子分析(EEM-PARAFAC)手段结合吸收光谱分析,研究了小球藻指数期和稳定期培养液中溶解有机物(DOM)在秋季天然太阳辐射作用下的光降解动力学特征.结果表明,小球藻生长过程中除能产生短波激发类腐殖质组分C1(其荧光峰的激发/发射波长位置为240,335 nm /406 nm)及类蛋白质组分C3(225,275 nm/334 nm)外,还会形成长波激发类腐殖质组分C2(260,395 nm /502 nm),表明C2组分并非仅有传统认为的陆源属性,同时也具有自生源属性.稳定期培养液的吸收光谱在250~300 nm范围内出现的肩峰,可用于指示水环境中现场自生源的贡献.不同生长时期培养液中DOM的吸收系数和荧光组分的降解动力学都符合一级反应方程.稳定期类腐殖质荧光组分(C1和C2)的光降解程度略高于指数期,但指数期类色氨酸组分(C3)的光降解程度略高于稳定期.经太阳辐照6 d后,小球藻培养液的吸收系数a₃₅₀及各荧光组分的平均损失率分别达到83.0%、84.0%、64.8%和80.0%,对应的半衰期只有1.6~5.0 d,揭示出藻类自生来源的DOM具有很强的光化学降解活性.