用膜结构参数模型评价溶解性有机物分子量分布对超滤膜污染的影响研究

研究了不同预处理对原水分子量分布的改变和对膜透水通量的影响,用膜污染的结构参数模型,评价了分子量分布对平均孔径和膜孔密度的影响。结果表明:(1)经过不同的预处理后,原水的分子量分布有所改变,混凝对大分子量有机物去除率较高,PAC吸附对小分子量有机物去除率较高,臭氧PAC联用预处理使大分子量有机物和小分子量有机物均有所去除。(2)分子量分布对膜通量影响较大。(3)通过试验并应用膜结构参数模型,评价了分子量分布对膜平均孔径和膜孔密度的影响,表明小分子量有机物易引起孔内吸附,大分子量有机物容易在膜面附着。     

MCM - 41中孔分子筛对铜离子吸附性能的研究

以MCM-41中孔分子筛（简称MCM-41）为吸附剂,对含Cu^2＋的溶液进行了静态吸附实验。结果表明：MCM-41对Cu^2＋的吸附量较大,约为283．0mg／g;Cu^2＋的去除率随吸附液pH的增大和吸附温度的升高而增加;MCM-41对Cu^2＋的吸附性能符合Langmuir吸附方程的特征;Cu^2＋的吸附过程为自发的吸热吸附过程。     

环境分子科学与环境纳米技术

传统的分子科学和新兴的纳米技术近年来广泛地渗入和覆盖了环境科学与技术,对环境污染现象的微观过程与机理研究注入了新的活力,进一步加深对环境污染从本质上的认识,为环境保护开展更高效的技术工艺开辟了新的途径．论综合评述了环境分子科学与环境纳米技术的发展概况,并对我国该领域的研究提出一些认识和讨论意见．     

白腐真菌酶学与分子生物学研究进展

白腐真菌对木质素降解的特异性生物学机制显示出其在复杂有机污染物降解中具有潜在应用前景。对白腐真菌酶学、自由基化学及分子生物学的国内外研究情况进行了较全面的介绍,以供国内同行参考。     

Analysis of Phytoplankton Community Structure Using Similarity Indices: A New Methodology for Discriminating Among Eutrophication Levels in Coastal Marine Ecosystems

Nine similarity indices based on phytoplankton community structure were examined for their sensitivity to assess different levels of eutrophication. Two phytoplankton data sets, one from an open coastal system and one from a semi-enclosed gulf, associated with different nutrient dynamics and circulation patterns were used for evaluating the indices. The results have shown that similarity indices, measuring interspecific association and resemblance of phytoplankton communities between enriched areas and control sites, were effective for detecting spatial and temporal dissimilarities in coastal marine ecosystems. The structure of the oligotrophic habitat as a potential source of ambiguity for the results was discussed, whereas the validity ranges and the potential applicability of this method were deemed to be dependent on the size of the fraction of the common species among the samples, and the similarity of the classification patterns resulted from this subcategory and those extracted from the overall community data. Furthermore, the study provides a new technique based on the use of the “Box and Whisker Plot” designed to distinguish opportunistic and rare phytoplanktonic species. The similarity indices, applied solely to the dominant species abundance, were more sensitive to resolve eutrophic, mesotrophic and oligotrophic conditions. This procedure can be proposed as an effective methodology for water characterization and can also be used as a qualitative tracer for detecting renewal processes of coastal marine ecosystems.     

A critique of EPA's index of watershed indicators

Numerous indices have been developed to assess water quality and the impact of programs to improve quality. The Index of Watershed Indicators (IWI) is one such index created by the US Environmental Protection Agency to assess watershed vulnerability and condition in the United States. The credibility and applicability of subjective indices such as IWI depends upon their ability to withstand tests that challenge their internal consistency and interpretation. This paper critiques IWI on the basis of these tests and other considerations, and suggests that explicitly basing the index on multiattribute utility theory and methods could help resolve many of these difficulties.     

聚丙烯酰胺降解菌的分离和鉴定

三次采油产生的大量含聚丙烯酰胺(PAM)的污水急需处理,其核心问题是PAM的生物化学降解。文章叙述了从含聚合物油田污水中分离到七株PAM降解菌的过程,并对其营养物体系进行了初步研究及分子生物学鉴定。结果表明,分离到的七株菌可以以PAM为唯一氮源和碳源进行生长,但是生长速度较慢,添加液蜡或酵母膏等可导致微生物菌群的共代谢,能加快PAM的生物降解。七株菌分别归类于放线杆菌纲和α-变形菌纲及芽孢杆菌,与数据库中已知菌的同源性均超过98%。     

沸石床多级生物膜焦化废水处理系统的NH+4-N去除稳定性研究

焦化废水处理中预处理蒸氨工艺不稳定容易引起生物处理出水NH⁺₄-N的波动,为了在有机物去除的同时提高生物系统对NH⁺₄-N的去除效果和稳定性,采用对NH⁺₄-N有良好吸附性能的天然斜发沸石为生物填料构建沸石床多级生物膜系统,考察了进水负荷对系统运行稳定性的影响、抗冲击负荷能力以及系统的功能分区和污染物迁移转化规律.结果表明,当系统进水NH⁺₄-N负荷≤0.21 kg/(m³·d)、COD负荷≤1.35　kg/(m³·d)时,出水NH⁺₄-N和COD的平均浓度分别为(2.2±1.2)mg/L和(228±60)mg/L,平均去除率分别达(99.1±0.5)%和(86.0±2.6)%.在低、高两次NH⁺₄-N冲击负荷［0.03　kg/(m³·d)和0.06　kg/(m³·d)］条件下,系统对NH⁺₄-N的平均去除率仍然分别高达99.0%和92.9%,高于对比系统的96.8%和89.3%,表现出良好的抗NH⁺₄-N冲击负荷性能与处理稳定性.系统好氧单元反应器沿程出现脱碳/硝化功能区(C/N区)和硝化功能区(N区),其中N区的NH⁺₄-N 降解速率为C/N区的2～8倍.系统进水中相对分子质量＜1×10³、 1×10³～1×10⁴、 ＞1×10⁴的TOC浓度分别为227.6、104.8和35.0 mg/L,处理出水中的TOC浓度分别为31.2、 22.9和31.5 mg/L,其中相对分子质量＜1×10³和1×10³～1×10⁴这2个范围的有机物降解良好,出水残余物质主要为相对分子质量＞1×10³的有机物.     

孔径调变对MCM-41分子筛吸附VOCs性能的影响

采用3种不同碳链长度的季铵盐表面活性剂C_nTAB(n=8,12,16)为模板剂,分别合成8-MCM-41、12-MCM-41和16-MCM-41介孔分子筛,并以甲苯、邻二甲苯、均三甲苯为吸附对象,考察了介孔分子筛动态吸附VOCs的性能.结果表明,通过减少表面活性剂的碳链长度,可以成功地把MCM-41分子筛的孔径调变为4.1、3.2和2.4 nm.吸附实验结果表明,当MCM-41孔径减小时,其对低浓度甲苯、邻二甲苯的吸附量大幅上升,均三甲苯存在孔道扩散效应,其吸附量增加不明显.吸附等温线表明,在2.4 nm孔道内,3种芳烃分子均属于典型的Langmuir单分子层吸附;当孔径大于2.4 nm时,芳烃分子出现明显的多层吸附和毛细凝聚现象.     

A/O-MBR处理餐饮废水过程中DOM特性解析

借助凝胶过滤色谱(GFC)分子量测定技术和三维荧光(EEM)光谱技术,对厌氧微网与好氧平板膜-生物反应器(A/O-MBR)联合处理餐饮废水过程中各阶段的溶解性有机物(DOM)及污泥胞外聚合物(EPS)的性质进行研究。分子量研究表明:好氧段污泥滤液的GFC谱图中在10 min以前有大分子物质析出,分析是微生物代谢产物;且随着处理过程的进行水样DOM中的分子量分布范围不断变宽。EEM光谱研究表明:进水、好氧段出水、好氧段污泥滤液的DOM中的2种主要荧光物质为高激发波长类色氨酸和可见区类富里酸,而厌氧段出水中仅有高激发波长类色氨酸,且峰强较强。同时,厌氧段出水中在形成可见区类富里酸的区域内有成峰趋势,分析是由较强的类色氨酸峰的掩蔽作用造成的。好氧段污泥EPS中存在3个明显的荧光峰,指示了色氨酸和腐殖酸的存在。