壳聚糖在活性污泥中的可生化性研究

以不同分子量和不同脱乙酰度的壳聚糖为对象,研究了壳聚糖溶液的COD和BOD5分别随分子量和脱乙酰度变化的规律,并将其应用于活性污泥法废水处理,研究了不同分子量和不同脱乙酰度的壳聚糖对微生物活性的影响及其抑菌作用。由壳聚糖溶液的BOD5/COD及其对微生物活性的影响初步得出壳聚糖在活性污泥中是不可生化的。     

Molarity provides better clarity – using molar-based data when evaluating chlorinated volatile organic compound impacted sites

Abstract

Chlorinated volatile organic compounds are common constituents observed at many contaminated groundwater sites. Common industry practice has been to measure these constituents in groundwater on a weight concentration basis (e.g. µg/l, mg/l). This paper highlights the use of molar-based concentrations, especially in the case of parent-daughter degradation sequences commonly observed with the chloroethene, chloroethane, and chloromethane families of compounds. Converting to molar-based concentrations provides the practitioner greater insight into groundwater plume behavior including better evaluation of degradation processes, remedial progress, possible commingling, and/or sourcing. For example, this paper provides a tank analogy to evaluate whether the commonly misinterpreted observation of “DCE-stall” may be occurring at a site. Multiple examples of the benefits of using molar-based concentration data are also summarized in a project case study presented herein. As demonstrated in this paper, molarity does provide better clarity and can be a powerful evaluation tool in the groundwater practitioner’s toolbox.     

Bleached kraft pulp mill discharged organic matter in recipient lake sediment

Environmental properties of organic matter contained halogen and sulfur were studied in sediments of bleached kraft pulp mill effluent (BKME) recipient lakes and 2 m³ outdoor enclosures (mesocosms). The BKME contributed to 1% (v/v) of the total water flow in the lake downstream of the pulp mill where the sediments contained 1.7 to 4 mg of tetrahydrofuran extractable organic halogen (EOX-Cl) and 0.6 to 0.8 mg of tetrahydrofuran extractable organic sulfur (EOS-S) g⁻¹ of organic matter. Upstream sediment contained 0.03 mg of EOXCl and 0.7 mg of EOS-S g⁻¹ of organic matter. EOX was a better indicator for the influence of BKME in the recipient sediment than EOS. The polarity of BKME contained EOX corresponded to log K^ow of < 1, and that of the downstream sediment contained EOX to > 4.5. HP-SEC analysis of the molecular weight distribution (MWD) of the EOX showed a peak between 300 to 600 g mol⁻¹ for the BKME and between 1000 to 2000 g mol⁻¹ for the downstream sediment. The MWD of the BKME contained EOS peaked at 300 to 1000 g mol⁻¹, and that of the downstream sediment contained EOS at 1000 to 5000 g mol⁻¹. These results indicate that BKME contained organic halogen and sulfur undergo major structural transformations when incorporated into sediment. The biota-to-sediment accumulation factor (BSAF) of EOX from sediments formed downstream of the mill and in the mesocosms to the lipids ofLumbriculus variegatus was 0.4 to 0.7. This is of a similar order of magnitude to the BSAF reported for 2,3,7,8-tetrachlorodibenzop-dioxin and 2,3,7,8-tetrachlorodibenzofuran.     

水生腐殖酸分子量分布研究——Ⅱ.腐殖酸凝胶色谱图峰加宽效应校正

研究了串联凝胶色谱系统的峰加宽效应.在该系统中,单分散标样的GPC谱图为低流出体积一侧较宽的不对称形式,以峰流出体积为界,这样的谱图可视作两个半侧正态函效的拼接.峰加宽效应还随淋出体积增大而加强,简单的直线方程可近似地描述分辨因子h随淋出体积的变化规律.在此基础上建立了腐殖酸GPC谱图峰加宽效应的校正方法.并根据实测结果计算了两个水生腐殖酸样品的分子量分布.     

利用前线分子轨道能预测有机物生物毒性的方法

本文以线性自由能理论为基础提出了一种利用分子轨道能预测有机物生物毒性的方法，并利用这种方法建立了预测氯代芳烃化合物发光菌毒性的定量相关方程。     

废水处理中的非传统脱氮途径

根据实验室小型SBR试验的结果，证实存在其它不同于传统的硝化和反硝化的脱氮途径。结合近几年来在生物脱氮理论方面新的研究进展，指出研究非传统脱氮途径的必要性和重要性，其中很有必要的一项工作是需对硝化、反硝化和脱氮过程作出明确的定义。     

分子遗传技术与生物遗传多样性研究

各种分子遗传技术为不同生物种类间进行直接比较和分子水平的遗传多样性的度量、研究提供了新的途径。本文讨论了此类分子水平研究所取得的一些新的进展，并指出了有关分子工具应用于生物多样性研究中存在的一些问题。     

分子微生物生态学技术在中国油田开发中的应用

分子微生物生态学技术近年来在研究油藏环境中微生物群落和生态系统等方面得到了广泛的应用,已经成为指导微生物采油技术开发和应用的一个不可或缺的工具.本文较系统地总结了我国利用分子微生物生态学方法研究油藏微生物群落结构的进展,其中包括大庆油田和西北部油田的16SrRNA基因序列分析,胜利油田16SrDNA的荧光标记末端多形态限制性片断分析技术(T-RFLP),以及吉林油田应用的DNA基因跟踪检测技术,并指出了存在问题和研究方向.图1参18     

卤代苯及其衍生物的比较分子场研究

用比较分子场（CoMFA）方法分析了一组卤代苯及其衍生物对发光菌的毒性数据，所建立的CoMFA模型有很好的自身一致性和较强的预测能力。对系列化合物的研究结果表明：该类化合物的立体效应是描述其毒性和进行构效关系研究的重要结构参数；毒性大小与取代基体积大小有关，取代基体积愈大则毒性愈大。     

新一代分子标记技术——AFLP

ＡＦＬＰ（Ａｍｐｌｉｆｉｅｄｆｒａｇｍｅｎｔｌｅｎｇｔｈｐｏｌｙｍｏｒｐｈｉｓｍ）是近年来发展起来的最有效的新一代分子标记技术．本文对ＡＦＬＰ的发生发展、基本原理、反应程序，在植物分子生物学研究中的应用以及方法本身的优缺点进行了介绍和评述．