Environmental occurrence of Q1, a C9H3C17N2 compound,that has been identified as a natural bioaccumulative organochlorine

Environmental appearance of Q1, a natural heptachloro compound with the molecular formula C₉H₃Cl₇N₂, was studied in samples from different sites all over the world. Q1 was expected to have a bipyrrole backbone, similar to other compounds ascribed to natural sources. A method for isolation of Q1 was developed by combination of adsorption chromatography on silica and normal phase HPLC with an amino phase. UV-detection of Q1 supports the aromatic character of the compound.

The high levels detected in samples of marine mammals and birds suggested that Q1 is both a persistent and a bioaccumulative contaminant. This was underscored by calculated log K_OW in the range of other lipophilic organohalogens. In accordance with earlier studies, highest Q1 concentrations were found in the Southern Hemisphere, but with a highly selective GC/ECNI-MS-SIM method, detection of Q1 was also achieved in many samples from the Northern Hemisphere. In addition to marine mammals and birds, Q1 was also detected in fish from the Mediterranean Sea and the Antarctic. Traces were also detected in SRM 1588 certified cod liver oil, but Q1 was not detected in fish from Hong Kong and Lake Baikal.     

La1-xCexFe0.7Co0.3O3-δ网状多层纳米纤维对碳烟催化燃烧性能研究

采用静电纺丝法制备了一系列钙钛矿催化剂La_(1-x)Ce_xFe_(0.7)Co_(0.3)O_(3-δ)(x=0、0.1、0.2、0.3和0.4),并采用XRD、SEM、FT-IR、H2-TPR和O_2-TPD等技术分析了Ce掺杂量对催化剂结构、微观形貌及理化特性的影响.同时,采用程序升温氧化(TPO)技术评价了催化剂对碳烟的催化燃烧活性,探讨了催化剂对碳烟的催化燃烧机理.结果表明:在La_(1-x)Ce_xFe_(0.7)Co_(0.3)O_(3-δ)中掺杂适宜的Ce有助于提高催化剂活性,改善催化剂比表面积和孔容积.在催化剂与碳烟松散接触条件下,当Ce掺杂量(质量百分比)为0.3时,所制备的La_(0.7)Ce_(0.3)Fe_(0.7)Co_(0.3)O_(3-δ)对碳烟的起燃温度(T_(ig))、最大燃烧温度(T_m)和燃尽温度(T_f)分别为329.5、409.8和421.1℃,呈现良好的催化氧化活性.碳烟最大转化效率为98.7%,平均活化能为123 kJ·mol~(-1),CO_2选择率为98.2%,实现了对柴油机碳烟排放污染物有效"过滤+催化燃烧"的双重目标.     

异质结型SnO2-TiO2纳米纤维光催化降解柴油机多环芳烃

采用同轴静电纺丝法制备了SnO_2-TiO_2纳米纤维,用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、红外光谱仪(FTIR)和紫外-可见光谱能谱仪(UV-Vis),表征了SnO_2-TiO_2纳米纤维相组成和微观形貌,评价了催化剂表面化学形态和吸光特性,研究了SnO_2含量、光源条件、温度和催化稳定性对降解萘污染物的影响规律.结果表明,催化剂Sn25对萘降解效率最高.在暗光、可见光和紫外光条件下,萘降解效率分别为13.8%、37%和98%.Sn25对萘降解稳定率(标准差率)为0.36%.利用催化剂Sn25对柴油机尾气中多环芳烃(PAHs)排放污染物光催化降解应用发现,Sn25对低苯环PAHs、中苯环PAHs和高苯环PAHs的平均催化降解效率分别为80.2%、75.4%和60.2%.表明SnO_2-TiO_2纳米纤维具有较强光催化降解多环芳烃污染物能力.     

大连市公众海洋环境意识调查分析

研究公众的海洋环境意识对建立正确的海洋环境观,遏制当前海洋环境恶化趋势,建立和谐的人海关系具有非常重要的意义。本文采用问卷和访谈的方法调查了大连市公众的海洋环境意识,并运用SPSS软件对调查数据进行了统计分析,结果显示,大连公众的海洋环境意识水平中等偏上,没有极端表现,但这一水平还有待提高。最后,提出加强青少年海洋环境意识教育,政府带头,公众提高自身参与意识等几点建议来加强大连市公众海洋环境意识的提高。     

Performance of a diesel engine with water emulsified diesel prepared with optimized process parameters

An attempt has been made to produce stable water–diesel emulsion with optimal formulation and process parameters and to evaluate the performance and emission characteristics of diesel engine using this stable water–diesel emulsion. A total of 54 samples were prepared with varying water/diesel ratio, surfactant amount and stirring speed and water separation was recorded after 24 and 48 hr of emulsification. The recorded data were used in artificial neural network (ANN)-particle swarm optimization (PSO) technique to find the optimal parameters to produce water–diesel emulsion for engine testing. The predicted optimal parameters were found as 20% water to diesel ratio, 0.9% surfactant and 2200 rpm of stirrer for a water separation of 14.33% in one day with a variation of 6.54% against the actual value of water separation. Water–diesel emulsion fuel exhibited similar fuel properties as base fuel. The peak cylinder gas pressure, peak pressure rise rate and peak heat release rate for water–diesel were found higher as compared to diesel at medium to full engine loads. The improved air-fuel mixing in water–diesel emulsion enhanced brake thermal efficiency (BTE) of engine. The absorption of heat by water droplets present in water–diesel emulsion led to reduced exhaust gas temperature (EGT). With water–diesel emulsion fuel, the mean carbon monoxide (CO), unburned hydrocarbon and oxides of nitrogen (NO_x) emissions reduced by 8.80, 39.60, and 26.11%, respectively as compared to diesel.     

油气长输管道施工企业清洁生产研究

清洁生产在油气长输管道施工领域涉及较少,观念和方法还未完全推广。油气长输管道施工企业与传统生产型企业有许多不同之处,以某企业清洁生产审核为例,就如何通过清洁生产审核挖掘清洁生产潜力来做探索性、建议性的研究。实践证明,该企业清洁生产机会的突破口为柴油消耗,通过柴油消耗平衡图的建立和重点耗油设备运行状况的调查,找到了降低柴油消耗的清洁生产方案,使企业达到了“节能、降耗、减污、增效”的目的。     

海南岛近岸海域环境容量与纳污总量分析

通过对海南岛"十二五"期间近岸海域纳污总量、环境质量状况及环境容量比较分析,得出各主要排污区环境容量的剩余环境容量。结果表明,全省主要污染物化学需氧量入海量仅占环境容量的2.6%,氨氮占环境容量的26.6%,虽然全省近岸海域环境基本未受污染物入海量影响,仍有较大的纳污空间,可利用的环境容量非常充裕。为避免出现排污达标但环境质量下降的状况,提出建立近岸海域主要污染物总量控制制度,由浓度控制到总量和浓度控制并存。     

包覆型纳米零价铁活化过硫酸处理柴油污染土壤

采用Tween-20作为包覆材料对纳米零价铁(n ZVI)进行改性(T-n ZVI),并利用T-n ZVI活化过硫酸盐(PS)降解柴油,同时与未改性纳米零价铁活化过硫酸盐体系(n ZVI/PS)进行对比.结果显示,在n ZVI/PS体系中,柴油降解率随着n ZVI及PS用量的增加而增加.在T-n ZVI/PS体系中,反应90 d后,柴油最大降解率为78%.与n ZVI/PS体系相比,T-n ZVI/PS体系所有组别的柴油降解率均有所提升,但提升幅度不大.同时对T-n ZVI活化PS的机理进行了推测.     

不同后处理器对DMCC发动机PM排放的影响

在一台整车排放达到国Ⅲ标准的YC4D140电控单体泵增压中冷柴油机上加装甲醇喷射系统,改成柴油甲醇组合燃烧(DMCC)发动机.使用AVL 415S烟度计和DMS 500快速颗粒物光谱仪研究不同后处理器对DMCC发动机颗粒物(PM)排放的影响.试验结果表明,各工况下单独CDPF、DOC+CDPF基本可以消除发动机产生的干炭烟.DOC+CDPF后处理方式与单独CDPF相比,颗粒物捕集效率明显提高,且前者对颗粒物中核态部分的捕集效果更加突出.甲醇掺烧后,炭烟和颗粒物几何平均直径降低.经CDPF和DOC+CDPF处理,415S烟度计测得的炭烟进一步降低;DMS颗粒物光谱仪显示的颗粒物粒径,因其中核态部分大部被氧化捕集而仅余较大几何平均直径的部分.小负荷时经CDPF和DOC+CDPF处理,颗粒物的几何平均直径会增大,大负荷时则相反.各工况下相比于CDPF,DOC+CDPF对核态颗粒物捕集更有效.     

中国海洋生态毒理学的研究进展

论述了海洋生态毒理学研究在中国的发展现状,结论为:污染物生物作用过程的研究主要进行了污染物在生物体内的累积与排放,在海洋食物链中的转移和潜在放大作用以及生物转化和生物降解方面的工作。污染物对海洋生物的影响,在急性毒性、慢性毒性方面进行了大量研究,另外对致畸和致突变现象以及海洋生物致毒和解毒的机制也进行了探讨。