荧光光谱法研究丙酮与牛血清白蛋白的相互作用特征

在模拟动物体生理条件和不同温度下,用荧光光谱、三维荧光光谱、同步荧光光谱、紫外可见吸收光谱法等研究了丙酮(ACET)与牛血清白蛋白(BSA)的相互作用,证实了丙酮有很强的猝灭BSA荧光强度的能力.分别用Sterr-Volmer方程、Lineweaver-Burk双倒数方程和热力学方程等分析和处理试验数据,得到了它们相互作用的生成常数KLV(平均值为7.073×106L·mol-1)、热力学参数(△Hθ、△Gθ和△Sθ的平均值分别为-3.982kJ·mol-1、-26.51 kJ·mol-1和73.31J·K-1)和结合位点数(平均值为1.266)等.这为研究ACET对BSA构象的影响、ACET的毒理效应和生物学效应提供了重要信息.     

荧光光谱法研究全氟辛酸与牛血清白蛋白的相互作用

在模拟生理条件下(pH7.4),采用荧光光谱研究环境污染物全氟辛酸(PFOA)与牛血清白蛋白(BSA)的相互作用.结果表明,PFOA对BSA有荧光静态猝灭作用.PFOA与BSA在温度277,298,310K的反应结合常数分别为1.06×105,7.12×104,5.68×104L/mol;在BSA上有1个PFOA的结合位点,该位点更接近于色氨酸残基.由反应的热力学可推断PFOA与BSA的相互作用力主要是静电引力和疏水作用力.与PFOA结合后,BSA分子构象发生变化,色氨酸残基附近疏水性增强,蛋白质分子结构趋于折叠状态;而酪氨酸残基附近亲水性增强,蛋白质分子结构趋于松散状态.     

联苯胺对牛血清白蛋白的荧光猝灭作用研究

用荧光光谱和紫外吸收光谱研究了联苯胺(BD)对牛血清白蛋白(BSA)的荧光猝灭作用.结果表明,联苯胺可以有规律地使BSA内源荧光猝灭,其猝灭机理为联苯胺与BSA形成复合物的静态猝灭.获得了不同温度下,联苯胺与BSA作用的结合常数和热力学参数,根据所得结果可推断联苯胺与BSA的主要作用力为氢键和范德华力.由Forster非辐射能量转移理论计算得出了联苯胺与BSA结合位置的距离.     

北京市地下水中高危害污染物筛选

地下水污染物对用水安全和人民健康造成了巨大的威胁.为开展地下水中高危害污染物筛选,改进了传统的危害评价方法,构建了涵盖毒理学优先指数法（Tox Pi）,吸收、分布、代谢、排泄（ADME）性质评估法和二模网络分析法的污染物危害评估-筛选-表征综合体系,针对北京市地下水中非靶检测到的234种疏水性有机污染物（HOCs）开展危害评估和毒害污染物筛选.利用Tox Pi方法筛选出危害潜力排名前20的污染物,在此基础上耦合其ADME性质进一步识别出17种高优先级HOCs,并通过二模网络分析,系统表征了这17种高优先级HOCs作用的基因分子靶点,通过关联性和加权平均度分析最终得到10种高危害的HOCs,并揭示其毒作用类型多集中于内分泌干扰效应、致癌效应以及遗传毒性.研究结果可为我国区域地下水污染物的防治提供技术支撑.     

某冶炼厂周边土壤碳组分与铜形态的相关性

研究了浙江某冶炼污染区农田土壤有机碳组分与铜(Cu)形态的相关关系.结果表明,研究区土壤Cu形态含量为铁锰氧化物结合态残渣态碳酸盐结合态有机质结合态可交换态,其中铁锰氧化物结合态Cu和残渣态Cu含量分别占全量的39.55%和39.19%.土壤p H值和碳组分对不同形态Cu含量存在一定程度的影响,其中p H值与碳酸盐结合态Cu和铁锰氧化物结合态Cu均呈显著正相关;溶解性有机碳(DOC)含量与可交换态Cu呈极显著正相关;富里酸(FA)含量与可交换态Cu呈极显著正相关,与有机结合态Cu呈显著正相关;胡敏酸(HA)含量分别与可交换态Cu和有机结合态Cu呈极显著正相关.土壤DOC、FA、HA的动态变化对这些在移动性上存在差异的Cu形态间的相互转化会带来一定程度的影响,从而改变土壤Cu的迁移能力和生物有效性.     

白洋淀入淀河流溶解有机物沿程变化特征及来源解析

采用紫外-可见吸收光谱、三维荧光光谱,结合平行因子分析、主成分分析等方法,分析了白洋淀3条入淀河流（府河、孝义河、白沟引河）中发色团溶解有机物（CDOM）的光谱特征,阐释了CDOM组成、来源及对水质的影响机制。结果发现：河流CDOM平均浓度顺序为府河>孝义河>白沟引河,其中,府河CDOM的芳香性与分子量高于其他河流,白沟引河腐殖化程度高于其他河流,孝义河CDOM中内源性物质占比高于其他河流;3条河流均检出类腐殖质组分C1、C2、C3和类蛋白质组分C4,其中C1、C2、C3来源相近,且与C4异源;3条河流各组分最大荧光强度和总荧光强度的沿程变化表明,府河CDOM为点源、面源混合来源,孝义河CDOM以点源输入为主,白沟引河CDOM来自水源本身。

     

几种低分子量有机酸和氨基酸对黄棕壤吸附菲的影响

采用批量平衡试验方法,研究了根系分泌物中几种常见的低分子量有机酸(LMWOA)和氨基酸对黄棕壤吸附菲的影响.结果表明,在供试有机酸和氨基酸的影响下黄棕壤对菲的等温吸附曲线仍呈显著的线性关系,分配作用是黄棕壤吸附菲的主导机制,供试LMWOA和氨基酸对黄棕壤吸附菲有抑制作用,且加入量越大,抑制作用越强.与氨基酸相比,LMW...     

Effect of different molecular weight organic components on the increase of microbial growth potential of secondary effluent by ozonation

Ozonation has been widely applied in advanced wastewater treatment. In this study, the effect of ozonation on assimilable organic carbon （AOC） levels in secondary effluents was investigated, and AOC variation of different molecular weight （MW） organic components was analyzed. Although the removal efflciencies were 47%-76% and 94%-100% for UV2s4 and color at ozone dosage of 10 mg/L, dissolved organic carbon （DOC） in secondary effluents was hardly removed by ozonation. The AOC levels increased by 70%-780% at an ozone dosage range of 1-10 mg/L. AOC increased significantly in the instantaneous ozone demand phase, and the increase in AOC was correlated to the decrease in UV254 during ozonation. The results of MW distribution showed that, ozonation led to the transformation of larger molecules into smaller ones, but the increase in low MW （〈1 kDa） fraction did not contribute much to AOC production. The change of high MW （〉100 kDa and 10-100 kDa） fractions itself during ozonation was the main reason for the increase of AOC levels. Furthermore, the oxidation of organic matters with high MWs （〉 100 kDa and 10-100 kDa） resulted in more AOC production than those with low MWs （1-10 kDa and 〈1 kDa）. The results indicated that removing large molecules in secondary effluents could limit the increase of AOC during ozonation.     

聚硅氯化铝混凝剂中Al(Ⅲ)水解聚合历程及铝硅作用特性研究

采用共聚与复合两种制备工艺，制备出了系列具有不同碱化度和不同Ａｌ／Ｓｉ摩尔比的聚硅氯化铝混凝剂，分析研究了ＰＡＳＣ中Ａｌ（Ⅲ）的水解－聚合历程以及聚硅酸与铝水解聚合产物的相互作用，探讨了ＰＡＳＣ溶液的酸解聚。     

Synthesis of lignin-based copolymer LSAA and the application on controlling non-point source pollution (NPS) resulted from surface runoff

In this article, alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin, starch, acrylamide and acrylic acid). Its practical application effect and environmental safety were studied. The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants. The runoff quantity was decreased by 16.67%-47.00% and the loads of total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were reduced by 17.78%-62.14%, 26.32%-59.91%, 26.67%-42.86%, and 22.18%-52.78%, respectively. Tests on its environmental safety showed that LSAA did no harm the soil. Compared with polyacrylamide (PAM), a dominant product in this field, LSAA exhibited similar effects and cheap cost. Thus, this study not only created a new product for controlling runoff water quality but also offered a beneficial application for industrial paper waste.