α-晶型碱式氯化铜的水环境效应研究

分别采用静态法和生长抑制法进行了α-晶型碱式氯化铜对水生生物模糊网纹蚤(Ceriodaphnia dubia)、呆鲦鱼(Pimephalespromelas)、月牙藻(Selenastrum bibraianum)和斜生栅列藻(Scenedesmus oblignus)的毒性试验,旨在明确α-晶型碱式氯化铜在水环境中对水生生物的毒性效应,为碱式氯化铜的生态评价提供安全依据。结果表明,碱式氯化铜对模糊网纹蚤48 h半数致死浓度(48 h LC50)、呆鲦鱼96 h半数致死浓度(96 h LC50)分别为29.7 mg.L-1、39.25 mg.L-1,对月牙藻72 h生长抑制浓度(72 h EC50)、斜生栅列藻96 h生长抑制浓度(96 h EC50)分别为11.1 mg.L-1、101 mg.L-1。以上结果表明,α-晶型碱式氯化铜不具有水生生物毒性。     

菱形藻生长及运动状态对农药草甘膦原粉的毒性响应

[目的]以淡水底栖硅藻(Nitzschia amplectens Hustedt)为受试藻,研究农药草甘膦原粉对其生长和运动状态的响应。[方法]以96 h EC50值、叶绿素a含量、运动状态等指标研究草甘膦对受试藻的毒性。[结果]草甘膦对受试藻96 h EC50值为29 mg/L;草甘膦对受试藻叶绿素a含量最大抑制率63.79%;运动状态随质量浓度增长受到抑制,2~5 d最明显。[结论]评价毒物对水环境的影响,浮游和底栖两类生物都应考虑在内。受试藻叶绿素a含量对草甘膦反应敏感。受试藻的运动状态可综合指示草甘膦毒性。     

几种藻类毒性试验统计方法的差异

在农药对藻类毒性试验结果的统计过程中，应用不同的统计方法，所得出的EC50值也存在一定差异。就所查到的统计方法进行了归纳，总结为三大类：面积法、生长速率法和相对数量法，并以实例证明这三种统计方法之问确实存在一定的差异。     

苯醚甲环唑对水生生物急性毒性评价

[目的]评价苯醚甲环唑对水生生物的毒性影响。[方法]采用藻类生长抑制试验法、静态水溞类急性活动抑制试验法、半静态水鱼类毒性试验法,分别研究苯醚甲环唑常用剂型对斜生栅藻、大型溞和斑马鱼的急性毒性效应。[结果]10%苯醚甲环唑水分散粒剂、20%苯醚甲环唑微乳剂、15%苯醚甲环唑悬浮剂、30 g/L苯醚甲环唑悬浮种衣剂对斜生栅藻生长抑制EC50(72 h)值分别为1.58、1.13、0.353、1.18 mg a.i./L,对大型溞急性活动抑制的EC50(48 h)值分别为4.07×10-2、0.219、0.461、0.717 mg a.i./L,对斑马鱼急性毒性的LC50(96 h)值分别为2.64、4.75、0.777、7.05×10-2mg a.i./L。[结论]10%苯醚甲环唑水分散粒剂、20%苯醚甲环唑微乳剂、15%苯醚甲环唑悬浮剂、30 g/L苯醚甲环唑悬浮种衣剂对斜生栅藻均为中等毒性,对大型溞的毒性等级依次为剧毒、高毒、高毒、高毒,对斑马鱼的毒性等级依次为中毒、中毒、高毒、剧毒。     

单嘧磺隆对3种鱼腥藻的毒性

通过不同除草剂质量浓度下鱼腥藻的生长状况比较及EC50的比较研究了新磺酰脲类除草剂单嘧磺隆对3种鱼腥藻的毒性作用,发现低剂量的单嘧磺隆（0．01～0．001mg／L）对藻类的生长无显著影响,而较高剂量（10-100mg／L）则会抑制藻类生长,3种鱼腥藻对单嘧磺隆的敏感性依次为：满江红鱼腥藻〉同氮鱼腥藻〉水华鱼腥藻。     

高效氯氰菊酯对斜生栅藻的毒性研究

以斜生栅藻细胞的生长状况、光合色素(叶绿素a、叶绿素b、类胡萝卜素)及蛋白质含量的变化作为指标,研究了不同质量浓度的高效氯氰菊酯对斜生栅藻的毒性效应.24 h、48 h、72 h、96 h的EC50(mg·mL-1)分别为11.71、6.19、4.03、2.87,斜生栅藻生长受抑制程度随高效氯氰菊酯质量浓度增加而加强,当高效氯氰菊酯的质量浓度超过10 mg·L-1时,斜生栅藻的生长几乎完全受到抑制.染毒96 h的斜生栅藻光合色素(叶绿素a、叶绿素b、类胡萝卜素)含量以及蛋白质含量随着高效氯氰菊酯的质量浓度的增加呈下降趋势,其中叶绿素a受到的影响最大.     

氟吗啉对非洲爪蟾胚胎发育的影响

简述了FETAX(Frog Embryo Teratogenesis Assay—Xenopus)试验的发展,并以非洲爪蟾(Xenopus laevis)处于8～11阶段的胚胎为试验材料,对杀菌剂氟吗啉进行了发育毒性的研究,通过对受试胚胎96h死亡数、半数致死浓度[LC50(96h)]、半数效应浓度[EC50(96h)]、致畸类型的统计,得出LC50(96h)值为83.15mg/L,EC50(96h)值为76.65mg/L,TI(LC50/EC50)为1.01≤1.5。结果表明,氟吗啉对非洲爪蟾的胚胎发育不具有致畸影响,但表现出一定的发育毒性。在氟吗啉质量浓度大于20mg/L时,可明显的抑制胚胎的孵化和体长生长的发育,表现的中毒症状有脊索弯曲、弯尾、眼部畸形、腹部水肿等。     

蒽、菲、芘对小新月菱形藻的毒性研究

在实验室条件下研究了蒽、菲、芘对小新月菱形藻的毒性,结果表明:蒽、菲、芘对小新月菱形藻48h EC50分别为196.54、125.60和152.86μg/L。蒽、菲、芘会对小新月菱形藻的抗氧化系统活性产生明显的影响,T-SOD活性、CAT活性和MDA含量有不同程度的升高。蒽、菲、芘两两联合对海洋微藻的毒性实验表明:菲+芘、蒽+菲、蒽+芘对3种微藻的联合毒性作用方式均为协同效应。     

光照强度对颤藻、小球藻、铜绿微囊藻的生长影响

该文采用颤藻(Oscillatoria sp)、小球藻(Chlorella)和铜绿微囊藻(Microcystis aeruginosa)为研究对象,通过检测叶绿素浓度(Chl-a)关键指标,考察了两种光照条件下(500、1 000 lux)三种藻类生长的规律。同时,利用SLogistic模型对三种藻生长规律进行拟合分析,为预测水华时期不同特征藻类的生长速率、潜能和规律提供参考。     

稻田常用6种化学农药对克氏原螯虾的安全性评价

[目的]研究6种化学农药对克氏原螯虾的毒性，评价其在稻虾生态种养田使用的安全性，为稻虾生态种养田化学农药的选择和正确使用提供科学指导。[方法]实验室采用室内半静态法测定了6种水稻田常用化学农药对克氏原螯虾24、48、72、96 h的毒性，应用概率单位法计算LC50、Turubell法计算安全质量浓度。[结果]200 g/L氯虫苯甲酰胺SC、10%三氟苯嘧啶SC、20%呋虫胺SG、75%三环唑WP、50%丁草胺EC和55%吡嘧·丙草胺WP对克氏原螯虾96 h LC₅₀分别为335.64、67.30、28.29、751.13、103.79、145.58 mg/L,6种化学农药对克氏原螯虾均为低毒；10%三氟苯嘧啶SC、20%呋虫胺SG、50%丁草胺EC和55%吡嘧·丙草胺WP对克氏原螯虾的安全质量浓度分别为21.41、5.40、1.71、9.60 mg/L，田间安全使用剂量分别为4281.64～6422.45、1079.99～1619.99、342.33～513.49、1919.38～2879.07 g a.i./hm2。[结论]6种化学农药均对克氏原螯虾低毒，在稻虾...     

Effects of surface activity on aquatic toxicity of binary surfactant mixtures

The purpose of this study was to discuss the effects of surface activity on the aquatic toxicity of binary surfactant mixtures comprising anionic, nonionic, and cationic surfactants. Surface tension was measured to determine the cmc (critical micelle concentration), and acute aquatic toxicity tests were conducted on Daphnia magna to obtain 24h-EC(50) (24h 50% effective concentration). TU (toxic unit) was calculated to evaluate the toxicity of the mixture. Most of the surfactant mixtures showed no synergistic increase in the aquatic toxicity. The mixture of anionic/nonionic surfactants showed synergistic interfacial activity with decreasing cmc, but the toxicity did not increase. The surface tension of the mixture at 24h-EC(50) (γ(tox)), which was used as an indicator of the toxic concentration, decreased considerably and TU was >1, indicating decreased toxicity. γ(tox) of the anionic/anionic surfactant mixture decreased when tested with hard water (hardness of 625 ppm). γ(tox) could not be used as a toxic indicator for the anionic/cationic surfactant mixtures because they showed aquatic toxicity before their surface tension began to decrease.     

5种新型杀菌剂对4种鱼的急性毒性及安全性评价

为评价5种新型杀菌剂的环境安全性,采用半静态法测定了其对4种鱼的急性毒性。结果表明,氟醚菌酰胺对斑马鱼、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)均大于100 mg/L,对青鳉的LC_(50)(96 h)为35.25 mg/L,其急性毒性均为低毒;氟吡菌胺对斑马鱼、青鳉、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为1.49、0.56、0.35、1.04 mg/L,其对斑马鱼和凤尾鲫急性毒性为中毒,对青鳉和稀有鮈鲫为高毒;苯噻菌胺对斑马鱼、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)均大于100 mg/L,对青锵的LC_(50)(96 h)为88.23mg/L,其急性毒性均为低毒;嘧菌酯对斑马鱼、青鳉、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为106.80、0.44、85.96、4.61 mg/L,其对斑马鱼和稀有鮈鲫急性毒性为低毒,对青鳉急性毒性为高毒,对凤尾鲫为中毒;醚菌酯对斑马鱼、青鳝、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为0.77、0.66、0.51、0.81 mg/L,其对4种鱼急性毒性均为高毒。明确这些药剂的环境安全性对指导其科学使用,保护环境生物均有较大意义。     

Amperometric screen-printed algal biosensor with flow injection analysis system for detection of environmental toxic compounds

A screen-printed algal biosensor was fabricated for evaluation of toxicity of chemicals. An algal ink was prepared by mixing unicellular microalga Chlorella vulgaris cells, carbon nanotubes and sodium alginate solution. The algal ink was immobilized directly on a screen-printed carbon electrode surface using screen-printing technique. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU) were evaluated as inhibition ratios of the reduction current. The concentrations that gave 50% inhibition of the oxygen reduction current (IC^′50) for atrazine and DCMU were 12 and 1 μmol dm⁻³, respectively. In comparison with the conventional algal biosensors, in which the algal cells were entrapped in an alginate gel and immobilized on the surface of a transparent indium tin oxide electrode, the present sensor is much smaller and less expensive, with the shorter assay time.     

Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator) Growth in Chlorella kessleri (Prey) Mass Cultures for Algae Biodiesel Production

A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC₅₀ was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II). The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm) had no effect on downstream fatty acid methyl ester extraction.     

Ecotoxicology Study of Various Homologues of Methyl Ester Sulfonates (MES) Derived from Palm Oil

Methyl ester sulfonate (MES) is an anionic surfactant derived from palm oil through sulfonation of fatty acid methyl esters. Due to limited ecotoxicological data on MES, this study was initiated to evaluate the ecotoxicological properties of MES and its impact to the environment. The respirometric method (OECD 301F) was used to monitor the biodegradation of various homologues of MES over 28 days. The algae growth inhibition test (OECD 201) was conducted to assess the effects of palm‐based MES towards green algae by exposing exponentially‐growing cultures of Pseudokirchneriella subcapitata (P. subcapitata) to five concentrations of MES with maximum concentrations of 100 mg/L. Results showed all MES samples were readily biodegradable, where the biodegradability of each homologue surpassed 60% within 28 days. It was also observed that the longer the carbon chain length of MES, the solubility and the biodegradability rate decreased. The ecotoxicity of C12 and C14 MES towards P. subcapitata after 72 h of experiment showed no inhibition of algae growth in C12 MES while, the growth of algae decreased as the concentration of C14 MES increases. The EC₅₀ value for C14 MES and C16 MES towards green algae was >100 and >10 mg/L, respectively. It can be concluded that C12 and C14 MES were practically non‐toxic towards P. subcapitata and the toxicity increased with an increase in chain length of the surfactant (EC₅₀ value decreases). Therefore homologues of palm‐based MES are not expected to cause environmental concern due to their biodegradability and low toxicity in the aquatic environment.     

白腐菌漆酶对莠去津最适降解条件的探讨

[目的]将白腐菌Coprinopsis cinerea okayama 7#130漆酶对三嗪类农药莠去津的降解条件进行了研究。[方法]向纯漆酶溶液中加入一定浓度的莠去津溶液进行降解反应,采用HPLC测定其含量,计算降解率。利用Box-Behnken设计对影响降解此农药的关键因素进行优化。[结果]经Design-Expert软件二次回归分析,得到莠去津降解的最适条件:pH值为6.9,温度为38.3℃,反应体系体积为5.3 mL,转速为186 r/min。在此条件下,莠去津降解率响应预测值为52.41%,验证值为52.32%。[结论]最适条件下的降解率提高了10%~15%,这为降低莠去津对环境的危害提供了科学依据。     

Optimization of atrazine removal from synthetic groundwater by electrooxidation process using titanium dioxide and graphite electrodes

ABSTRACT

Atrazine is used in agriculture and is known for its high toxicity. It therefore poses a risk to surface and ground waters, and human life. In this study, an electrochemical method was optimized for atrazine removal from SGW using TiO₂ and graphite electrodes. A comparison between one factor at a time period optimization and Box-Behnken design (BBD) optimization using RSM was carried out to select the optimum conditions. The results show excellent atrazine removal efficiency (99.70%) and close optimum conditions for both applied methods (pH 7 and 7.4; current 2.5 and 2 A and time 14 and 12.12 min, respectively).     

A simple model for prediction of acid gas solubilities in alkanolamines

A simple model has been created for predicting acid gas vapor-liquid equilibrium (VLE) in alkanolamines. The model is simple enough to use in a hand held calculator, but its structure is derived from theory. Model parameters were obtained by regression of experimental VLE data. The model is valid for total gas loadings from 0.003 to 0.8 and over a wide range of temperatures and amine concentrations. Partial pressure predictions are shown to agree with a more complex model over seven orders of magnitude in pressure. Heat of absorption values derived from the model are also shown to agree with literature sources. Parameters are given for the MDEA-H₂O-H₂S-CO₂ and DEA-H₂O-H₂S systems.     

Experimental and Theoretical Electron Paramagnetic Resonance (EPR) Study on the Temperature-Dependent Structural Changes of Methylsulfanylmethane

Methylsulfonylmethane (or dimethyl sulfone), a naturally produced and vitally important organosulfur compound in living organisms, was irradiated with gamma rays, and the produced radicals were investigated using electron paramagnetic resonance spectroscopy at different temperatures. The structure and behavior of the radical changed when the temperatures varied. The hyperfine splitting of the CH(3) group was small, and the (33)S splitting was relatively high between 80 and -50 °C. When the temperature was between -50 and -160 °C, the (33)S splitting became small and the CH(3) splitting was higher. However, the group kept rotating; therefore, only the isotropic splitting values were measured, and the g-values were anisotropic. When the temperature decreased below -180 °C, the CH(3) group stopped rotating, and the hydrogen splitting values became nonequivalent due to an inhomogeneous electron distribution. The observed structures can be explained by referring to both the experimental and theoretically calculated values reported.     

阿特拉津的微生物降解特征研究

应用了从农药厂阿特拉津生产车间污泥中分离出的菌种AT菌，进行了系列降解实验。不同基质浓度的降解实验表明，在农药污染质阿特拉津的低浓度体系中，AT菌降解阿特拉津的反应符合一级动力学模式，属于米氏方程曲线的第一阶段的情形，并拟合出关系式V=0．064S；AT菌在外加氮源、碳源及以阿特拉津为唯一碳源和氮源等条件时对农药污染质阿特拉津均具有降解能力，且在以阿特拉津为唯一氮源(外加碳源)条件下的降解效果最好，此时的降解率为30．39％；模拟治理中，设计了细菌的投放方式以模拟野外条件下的菌种投加条件，难于生物降解的污染质阿特拉津的一次投菌降解率达到31．08％。