溶液中阴离子对UV/H2O2降解十二烷基苯磺酸钠的影响及其机理

研究了UV/H2O2工艺对十二烷基苯磺酸钠(LAS)的去除效果、溶液中阴离子对LAS降解的影响及机理.结果表明:UV/H2O2工艺可以有效地去除水中的LAS;在H2O2投加量为8 mg/L,14 W低压汞灯照射下,LAS在蒸馏水和自来水中的反应速率常数分别为0.018 0 、0.012 2 min-1;NO-3、Cl-、SO2-4和HCO-3对LAS光降解有抑制作用,当该4种离子摩尔浓度均分别为5、10、15 mmol/L时,对LAS光降解的抑制程度为HCO-3》NO-3》Cl-》SO2-4,且随着离子摩尔浓度的增大,抑制作用增强;LAS在自来水中的反应速率常数低于在蒸馏水中的反应速率常数是由于水中多种离子影响的结果.     

Oviposition by butterflies on young leaves: Investigation of leaf volatiles

Summary Various butterflies select young foliage on which to lay their eggs; volatiles emitted by young and old leaves have been compared (by sorption enrichment, followed by GC-MS) to gauge possible qualitative and quantitative differences between the two age groups. The plants investigated are cabbage (Brassica oleracea), two milkweeds (Asclepias syriaca andA. curassavica), the bitter orange (Citrus aurantium) and the lime (C. aurantiifolia). The chemical compounds identified belong to three classes, isoprenoids, fatty acid derivatives and benzenoids. Quantitative differences were found between young and old leaves, of which a few may be characteristic of young leaves only. Thirty-four single trials withDanaus plexippus exposed to volatiles from young and old leaves are recorded.     

Review and comparison of methods to study the contribution of variables in artificial neural network models

Convinced by the predictive quality of artificial neural network (ANN) models in ecology, we have turned our interests to their explanatory capacities. Seven methods which can give the relative contribution and/or the contribution profile of the input factors were compared: (i) the ‘PaD’ (for Partial Derivatives) method consists in a calculation of the partial derivatives of the output according to the input variables; (ii) the ‘Weights’ method is a computation using the connection weights; (iii) the ‘Perturb’ method corresponds to a perturbation of the input variables; (iv) the ‘Profile’ method is a successive variation of one input variable while the others are kept constant at a fixed value; (v) the ‘classical stepwise’ method is an observation of the change in the error value when an adding (forward) or an elimination (backward) step of the input variables is operated; (vi) ‘Improved stepwise a’ uses the same principle as the classical stepwise, but the elimination of the input occurs when the network is trained, the connection weights corresponding to the input variable studied is also eliminated; (vii) ‘Improved stepwise b’ involves the network being trained and fixed step by step, one input variable at its mean value to note the consequences on the error. The data tested in this study concerns the prediction of the density of brown trout spawning redds using habitat characteristics. The PaD method was found to be the most useful as it gave the most complete results, followed by the Profile method that gave the contribution profile of the input variables. The Perturb method allowed a good classification of the input parameters as well as the Weights method that has been simplified but these two methods lack stability. Next came the two improved stepwise methods (a and b) that both gave exactly the same result but the contributions were not sufficiently expressed. Finally, the classical stepwise methods gave the poorest results.     

LAS、AE降解菌的筛选及降解效率的研究

以某合成洗涤剂厂曝气池活性污泥为菌种来源，表面活性剂直链烷基苯磺酸钠（LAS）及脂肪醇聚氧乙烯醚（AE）为唯一碳源进行选择培养，从中分离出5株降解LAS、AE能力强的菌株。根据各菌株菌体形态、染色反应和生理生化反应，分别对5菌株进行了菌种鉴定，并在不同的温度、pH值和供氧的情况下对5株菌株进行培养，研究菌株生长所适宜的环境条件。同时根据LAS、AE对水绵伤害实验，以生物监测的方法对菌株降解LAS、AE的效率进行了研究。     

滇池烷基苯磺酸钠的分布,降解及对鲤鱼的危害效应

研究表明滇池水中ＬＡＳ含量为０．０１８～０．０２９ｍｇ／ｌ，局部水域达０．２～０．７ｍｇ／ｌ；ＡＢＳ强烈地吸附在底质中，以湖体呈曲线分布，平均含量高达０．４３ｍｇ／ｋｇ，１６ｈ内ＬＡＳ动态降解率比静态降解率高２．２倍，不同浓度的ＬＡＳ对滇池鲤鱼的结果表明，５～３５ｍｇ／ｌ浓度水中，溶解氧下降，ｐＨ值升高，产生急性危害效应，半致死浓度４８ＴＬ５０为３．０ｍｇ／ｌ，完全浓度为０．３ｍｇ／ｌ。当ＬＡＳ含     

海洋污染对毛蚶过氧化氢酶影响研究

采用体内染毒实验，研究了海洋常见污染物O#柴油、二甲苯以及重金属镉（Cd^2 ）对毛蚶（Scpharca subcrenata)肌肉过氧化氢酶（CAT）活性的影响；并探讨了O#柴油、二甲苯体外染毒对毛蚶肌肉CAT活性的影响。结果表明：在实验剂量范围内，3种污染物在低浓度下对毛蚶肌肉组织中CAT活性均起诱导作用，高浓度则表现为不同程度的抑制作用；O#柴油、二甲苯体外染毒对毛蚶肌肉CAT活性均产生诱导作用；无论体外、体内染毒毛蚶肌肉CAT活性与各污染物浓度间均存在剂量/效应关系。     

住宅装修污染及其防治

因装修引起的住宅室内空气污染主要包括甲醛污染、苯类污染、氨气污染和氡气污染。本文分析了上述污染物的来源。介绍了光触媒、臭氧、负离子、活性炭、抗污染花草等多种室内空气污染治理方法，比较了各种治理方法的利弊特点。     

A review of atmospheric benzene homologues in China: Characterization, health risk assessment, source identification and countermeasures

Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol (SOA) in the atmosphere, in addition, some toxic species are harmful to human health. Strict countermeasures have been taken to fight air pollution since 2013, and total amount control of volatile organic compounds is being promoted in China at present. Therefore, it is important to understand the pollution situation and the control status of ambient benzene homologues in China. This paper reviews research progress from published papers on pollution characteristics, atmospheric photochemical reactivity, health risk assessment and source identification of ambient benzene homologues in recent years in China, and also summarizes policies and countermeasures for the control of ambient benzene homologues and the relevant achievements. The total ambient levels of benzene, toluene, ethylbenzene and xylenes (BTEX) shows a declining tendency from 2001 to 2016 in China. The mass concentrations of BTEX are generally higher in southern regions than in northern regions, and they present vertical decreasing variation characteristics with increasing altitude within the height range of about 5500 m. Toluene has the highest ozone formation potential and SOA formation potential both in urban areas and background areas, while benzene poses an obvious carcinogenic risk to the exposed adult populations in urban areas. Source identification of ambient benzene homologues suggested that local governments should adopt differentiated control strategies for ambient benzene homologues. Several recommendations are put forward for future research and policy-making on the control of ambient benzene homologues in China.     

Intranasal administration of tetrabromobisphenol A bis(2-hydroxyethyl ether) induces neurobehavioral changes in neonatal Sprague Dawley rats

Tetrabromobisphenol A (TBBPA) and its derivatives are now being highly concerned due to their emerging environmental occurrence and deleterious effects on non-target organisms. Considering the potential neurotoxicity of TBBPA derivatives which has been demonstrated in vitro, what could happen in vivo is worthy of being studied. Tetrabromobisphenol A bis(2-hydroxyethyl ether) (TBBPA-BHEE), a representative TBBPA derivative, was selected for a 21-day exposure experiment on neonatal Sprague Dawley (SD) rats through intranasal administration. The neurobehavioral, histopathological changes, and differentially expressed genes based on RNA microarray were investigated to evaluate the neurological effects of this chemical. The results indicated that TBBPA-BHEE exposure significantly compromised the motor co-ordination performance and the locomotor activities (p < 0.05). The neurobehavioral phenotype could be attributed to the obvious histopathological changes in both cerebrum and cerebellum, such as neural cell swelling, microglial activation and proliferation. A total of 911 genes were up-regulated, whereas 433 genes were down-regulated. Gene set enrichment analysis showed multiple signaling pathways, including ubiquitin-mediated proteolysis and wingless-int (Wnt) signaling pathway etc. were involved due to TBBPA-BHEE exposure. The gene ontology enrichment analysis showed the basic cellular function and the neurological processes like synaptic transmission were influenced. The toxicological effects of TBBPA-BHEE observed in this study suggested the potential neuronal threaten from unintended exposure, which would be of great value in the biosafety evaluation of TBBPA derivatives.     

不同含水量细砂介质中挥发苯的有效扩散系数研究

挥发性有机污染物在土壤多孔介质中的有效扩散系数是土壤气相抽提(soil vapor extraction,SVE)传质过程中的一个重要参数.笔者以苯为研究对象,采用土柱扩散试验,对不同含水量条件下挥发苯在细砂介质中的有效扩散系数和扩散规律进行研究.结果表明,对于吸附型矿物含量少的细砂介质,含水量大小在一定程度上影响了挥发苯的扩散过程.含水量在50 g·kg-1时,扩散最快;低于50 g·kg-1时,随含水量增大扩散能力增强;高于50 g·kg-1时,扩散能力则随含水量增大而减弱.同一扩散柱中,随着扩散距离增加,挥发苯的有效扩散系数增大,这可能与其蒸汽分压降低有关.