乌鲁木齐空气颗粒物中PAHs碳同位素组成及来源解析

报道了乌鲁木齐城区空气颗粒物中多环芳烃(PAHs)化合物的稳定碳同位素组成特征,解析了PAHs的来源.气相色谱/燃烧系统/同位素质谱分析表明,该市空气颗粒物中PAHs化合物的δ¹³C值为-23.5‰～-31.3‰,随着分子量的增大,PAHs化合物中13C含量降低.利用同位素质量平衡二元模型,计算了燃煤污染源与机动车排气对城区苯并(a)芘、茚并(1,2,3-cd)芘和苯并(ghi)苝的贡献,前者分别为72%、97%和95%,后者分别为28%、3%和5%.苯并(a)芘、茚并(1,2,3-cd)芘和苯并(ghi)苝的相对含量分别为2.8%,29.1%和25.1%,占PAHs总量的57%,计算的三者的燃煤污染源总贡献量为78.6%,与利用化学质量平衡模型计算得出的结果(84%的PAHs源于燃煤)相近.     

软锰矿浆催化氧化烟气SO2的动力学初探

对高液固比软锰矿浆与烟气SO2产酸过程进行了研究,在考察液固比、氧浓度和pH值等对反应过程影响的实验基础上,认为高液固比下主要发生的是软锰矿浆对烟气SO2的催化氧化生成硫酸的反应,并认为在[O2]控制区内,反应可以分为线性阶段和幂函数2个反应阶段.     

复合表面活性剂对燃煤陶瓷窑炉黑烟润湿作用的研究

为了有效控制燃煤陶瓷窑炉黑烟的污染,根据理论和实验研究的结果,选择合适的润湿剂和助剂,研究了阴离子表面活性剂Y1、非离子表面活性剂F1与无机盐Z1复配后溶液表面张力的变化,筛选出了表面张力较小的配比。利用所选配比对燃煤陶瓷窑炉黑烟的润湿作用进行了W alker实验研究和理论分析。实验结果表明,0.5 mmol/L Y1+50mmol/L Z1+0.03 mmol/L F1的配比对黑烟的润湿作用较好。并对其润湿机理进行了探讨。     

环境中丙烯酰胺检测方法和健康危害的研究进展

丙烯酰胺广泛应用于工业生产,是一种潜在的环境污染物。本文从丙烯酰胺的检测方法和健康危害2个方面总结了目前的研究进展。检测方法上,以高效液相色谱-质谱串联法(HPLC-MS/MS)最为常用,一些新技术也逐渐应用到分析中。健康危害方面,丙烯酰胺可引起实验生物的神经、生殖、遗传和发育等毒性和潜在致癌性。其毒性机理为:直接损坏神经元;使活性氧(ROS)积累导致氧化损伤;诱发基因位点突变,或与DNA形成加合物而致其损伤等。鉴于目前研究存在的问题,对以后的工作进行了展望:加强监管与治理工作,保护生态环境和人类健康;深入开展丙烯酰胺对生物体的毒性效应研究;加强我国环境中丙烯酰胺的跟踪监测工作;建立一种快捷的生物测试系统来评估水体(尤其是海洋环境)中丙烯酰胺的毒性风险。     

A Novel Hyperbranched Polymeric Flocculant for Waste-Water Treatment

Cationic hyperbranched oligomer poly(N-acryloyl-1,2-diaminoethane hydrochloride) (HADE) was firstly synthesized by Michael addition reaction. And then, a series of cationic flocculants poly(acrylamide/N-acryloyl-1,2-diaminoethane hydrochlorides) (PAM-HADEs) with hyperbranched structure was prepared from HADE as macro-monomer and acrylamide (AM). The structures of PAM-HADEs were characterized by Fourier transform infrared spectrometry, ¹H and ¹³C nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). And the properties were systematically evaluated by intrinsic viscosity, zeta potential and hydrodynamic radius. The mechanism of the cationic hyperbranched copolymer used in water treatment was extensively studied via a jar test in which the transmittance of the supernatant, settling time, and average floc size were used to evaluate the flocculability. Compared with the linear flocculant poly (acrylamide/liner-N-acryloyl-1,2-diaminoethane hydrochloride) (PAM-LADE), the novel hyperbranched polymeric flocculants exhibited outstanding flocculability which were reflected by shorter settlement time, high transmittance and large floc size. The primary cause that PAM-HADEs owned excellent flocculability is the more stretching configuration and less chains entanglement of PAM-HADEs in waste-water due to their hyperbranched structure compared with that of the linear PAM-LADE which exhibited curly coil configuration. On the other hand, abundant and exposed cationic terminal groups of PAM-HADEs originated from their hyperbranched structure also hint higher flocculation capacity. At optimum dosages of the polymer, the transmittance of the supernatant is less at low and high pH values, indicating that the natural pH (pH 7.29) of the suspension is the most appropriate pH for the flocculation.     

Long-term recovery narratives following major disasters in Southeast Asia

Regional Environmental Change - Most studies of major disasters focus on the impacts of the event and the short-term responses. Some evaluate the underlying causes of vulnerability, but few...     

广东经济鱼类不饱和脂肪酸的含量分析与组成特征评价

采用水解提取-气相色谱法测定鱼肉中脂肪酸的含量和组成,采用元素分析仪-同位素比值质谱法(EA-IRMS)测定鱼肉碳稳定同位素比值(δ~(13)C).开展广东沿海地区主要经济鱼类肌肉脂肪酸的含量分析及组成特征评价研究.研究表明,25种经济鱼类鱼肉中主要含有单不饱和脂肪酸、n-6和n-3系列多不饱和脂肪酸,以及少量反式脂肪酸(TFAs);鱼肉的优势脂肪酸为油酸(OA)、亚油酸(LA)和二十二碳六烯酸(DHA);鲻鱼含有较高的二十碳五烯酸(EPA)和DHA,合计370.0 mg·(100 g)~(-1);鲻鱼鱼肉中TFAs的含量(280.0 mg·(100 g)~(-1))远高于其它品种鱼类;鲢鱼和黑鲷EPA+DHA的含量较高,分别为(154.4±100.0 mg·(100 g)~(-1)和1287±291.1 mg·(100 g)~(-1),两种鱼均具有较好的商业开发价值;统计学分析结果表明了鱼类的不饱和脂肪酸在组成上具有种属差异,揭示了浮游食性的鱼类其鱼肉组织中MUFAs、n-6 PUFAs以及n-3 PUFAs的含量高于底栖食性的鱼类.鱼肉脂肪酸的组成差异较大,表现为品种、空间以及食性差异.建议市民在日常膳食中丰富食鱼的种类和数量,警惕过多地食用单一品种鱼类(尤其是鲻鱼)而导致TFAs摄入过多的风险,从而确保鱼类脂肪酸的平衡摄入.     

Developing a framework for integrating local and scientific knowledge in internationally funded environment management projects: case studies from Kien Giang Province,Vietnam

Local and scientific knowledge, when adequately and properly integrated, produces enormous benefits for natural resource management in comparison to a single knowledge system being used. Adequate and proper integration has major constraints that include ineffective use of the integrated knowledge, thoroughly inclusive processes, and true public participation. A six-stage framework is developed using the results and conclusions of two case studies regarding sustainable management of eroding mangrove-dominated muddy coasts in Vam Ray, Hon Dat district, Kien Giang Province, Vietnam. The framework does not stop with the creation of integrated knowledge, but should undergo a longer process. The new knowledge developed in this framework is the understanding gained and lessons learnt during the testing of products of multiple knowledge systems in a local context rather than products of integrated knowledge systems themselves. The Vam Ray framework promotes a high level of participation, effective use of products of multiple knowledge systems, maximum integration of local and scientific knowledge, local ownership, and sustainability. Therefore, the Vam Ray framework adds a new dimension to the literature in relation to integration of local and scientific knowledge in natural resource management.     

离子液体氯化1-辛基-3-甲基咪唑对洋葱的遗传毒性作用

为探讨咪唑类离子液体氯化1-辛基-3-甲基咪唑([C_8mim][C1])对洋葱的遗传毒性,用浓度分别为2.5、5、10和20mmol·L~(-1)的[C_8mim][C1]处理洋葱内表皮细胞和洋葱根尖8 h,用浓度为10 mmol·L~(-1)的[C_8mim][C1]处理洋葱内表皮细胞和洋葱根尖4 h、8 h、12 h和24 h,研究[C_8mim][C1]对洋葱内表皮细胞核的影响和对洋葱根尖有丝分裂指数和染色体畸变的影响。结果显示,与对照组相比,随着[C_8mim][Cl]处理浓度和时间的增加,洋葱内表皮细胞核偏移率明显升高,根尖细胞有丝分裂指数显著降低,染色体畸变现象明显,畸变率升高。研究表明,当浓度达到2.5 mmol·L~(-1)时,[C_8mim][Cl]对洋葱具有遗传毒性。     

Macroinvertebrate community in relation to water quality and riparian land use in a substropical mountain stream,China

Exploring how water quality and land use shape the benthic macroinvertebrate community composition is of widespread interest in biodiversity conservation and environmental management. In this study, we investigated the structures of benthic macroinvertebrate assemblages and their environmental controls in terms of water quality and riparian land use in the Jinshui River, China. We carried out three campaigns including wet season (August 2009), dry season (November 2009), and normal season (April 2010) based on the hydrological regime in Jinshui basin. The result showed that macroinvertebrate assemblage variations were better explained by water quality factors than land use based on variance partitioning procedure. The land use of 2 km upstream from the sampling sites had explained more variation than that of the whole riparian zone in upstream catchment on macroinvertebrate community, and land use of 2 km upstream also had more interactions with water quality. Canonical correspondence analysis (CCA) indicated that the elements or nutrient of magnesium (Mn), selenium (Se), strontium (Sr), silicon (Si), dissolved inorganic nitrogen (DN), sulfur (S), total organic carbon (TOC), and total nitrogen (TN) in water exhibited a strong relationship with macroinvertebrate assemblages. However, the variance in water quality explained by land use was lower than that explained by water quality in rivers using redundancy analysis. Our study suggested that proximate factors (i.e., water quality) were more important to interpret the macroinvertebrate community compared to ultimate factors (i.e., land use) for macroinvertebrate assemblages in river system.