Simultaneous elimination of cyanotoxins and PCBs via mechanical collection of cyanobacterial blooms: An application of “green-bioadsorption concept”

In this study, the distribution, transfer and fate of both polychlorinated biphenyls (PCBs) and cyanotoxins via phytoplankton routes were systematically investigated in two Chinese lakes. Results indicated that PCB adsorption/bioaccumulation dynamics has significantly positive correlations with the biomass of green alga and diatoms. Total lipid content of phytoplankton is the major factor that influences PCB adsorption/bioaccumulation. Cyanobacterial blooms with relatively lower lipid content could also absorb high amount of PCBs due to their high cell density in the water columns, and this process was proposed as major route for the transfer of PCBs in Chinese eutrophic freshwater. According to these findings, a novel route on fates of PCBs via phytoplankton and a green bioadsorption concept were proposed and confirmed. In the practice of mechanical collections of bloom biomass from Lake Taihu, cyanotoxin/cyanobacteria and PCBs were found to be removed simultaneously very efficiently followed this theory.     

Sources and distribution of sedimentary organic matter along the northern Bering and Chukchi Seas

In this study, lignin-derived phenols were used to determine the sources and distribution of sedimentary organic matter along the northern Bering Sea and Chukchi Sea of the Arctic Ocean. The lignin parameter syringyl/vanillyl (S/V) and cinnamyl/vanillyl (C/V) ratios are used to indicate vegetation sources; and the ratios of vanillic acid/vanillin, (Ad/Al)v and syringic acid/syringaldehyde, (Ad/Al)s are used as indicators of lignin diagenesis. Results showed the predominance of woody gymnosperm signal at the easternmost location in the northern Bering Sea, a mixture of refractory non-woody angiosperm and fresher gymnosperm tissues in the Chukchi Sea, and signal of fresher woody gymnosperm tissues in the northernmost locations in the Chukchi Sea. The lignin materials showed gradual increase in decomposition stage during transport along the northern Bering Sea. Hydrodynamic sorting process, which is the retention of coarser materials nearshore and transportation of finer particles farther offshore, most probably occurred along the east coast of the northern Bering Sea. In Chukchi Sea, the non-woody angiosperm tissues could have originated from the Canadian Arctic and gymnosperm tissues could be from the Russian Arctic side. The fresher materials in the northernmost Chukchi Sea could have been transported here via the ice-rafting process. Detection of fresh lignin materials and the occurrence of lignin decomposition mean that this region could be sensitive to the impact of climate change.     

Hydrolysis mechanism of carbendazim hydrolase from the strain Microbacterium sp. djl-6F

The carbendazim(MBC) hydrolyzing enzyme gene was cloned and heterologously expressed in Escherichia coli BL21(DE3) from a newly isolated MBC-degrading bacterium strain Microbacterium sp. strain djl-6F. High performance liquid chromatography-mass spectrometry(HPLC-MS)analysis revealed that purified MheI-6F protein catalyzes direct hydrolysis of MBC into2-aminobenzimidazole(2-AB) with a high turnover rate and moderate affinity(Kmof6.69 μmol/L and kcatof 160.88/min) without the need for any cofactors. The optimal catalytic condition of MheI-6F was identified as 45°C, pH 7.0. The enzymatic activity of MheI-6F was found to be diminished by metal ions, and strongly inhibited by sodium dodecyl sulfate(SDS).Through generating amino acid mutations in MheI-6F, Cys16 and Cys222 were identified as the catalytic groups that are essential for the hydrolysis of MBC. This is the first report on the biodegradation of MBC at the enzymatice level.     

亚洲季风变迁与全球气候的联系

通过研究冰期-间冰期至百年尺度亚洲季风的演变特征,阐明了季风变化同南北半球冰量、太阳辐射、大洋环流、热带辐合带等气候系统内外部因子的动力联系。在海-陆-气相互作用的框架下提出了"冰期-间冰期印度季风变化动力学"新理论,揭示大西洋经向环流对东亚季风突变事件的影响和动力过程,探讨了全新世亚洲季风变化的时空特征和控制因素。该项成果以亚洲季风变迁历史和机理为主线,从地球系统科学的视角,将亚洲古季风研究拓展为多尺度与多动力因子、区域与全球相结合的集成研究,推动了与季风相关的过去全球变化科学的发展。     

纳氏试剂比色法测定污水中氨氮的优化研究

纳氏试剂比色法测定污水中氨氮,其蒸馏预处理过程存在耗时长、馏出液接收不便和操作繁琐等问题.文章对预处理及测定方法进行了优化,提出将水样蒸馏体积减少为50 mL,后期比色体积减少为25 mL,并去除硼酸吸收液,改为直接接收馏出液.经验证,其结果与国标方法无显著性差异,标样验证相对误差为-0.8%~0.9%,实际样品测定结果的相对标准偏差为0.9%~4.4%,加标回收率为94%~107%.优化的方法测量数据稳定,结果准确,在测定污水中氨氮具有实际应用意义.     

广东省春节期间空气质量特征及预报方法研究

2017年春节期间广东省环境空气质量自动监测站的数据分析结果表明:春节假期广东省空气质量等级变化较大.除夕全省空气质量为良;初一,全省以良和轻度污染为主,粤东出现重度污染,粤西和粤北出现中度污染,可能与除夕夜烟花爆竹燃放有关;初二起,全省空气质量逐渐转为优良.首要污染物以PM2.5和O3为主.现有的NAQPMS和CMAQ空气质量预报模型在污染相对严重的初一表现较差,主要是因为数值模型未能考虑到烟花爆竹燃放等排放源的输入.     

基于三维成像技术的污泥菌群中抗生素抗性基因转移动态特征研究

应用活细胞三维成像技术,实时和原位观测了活性污泥菌群中抗生素抗性基因转移动态特征.微流控芯片是一种细菌生长的良好载体,活细胞成像系统低光毒性不损伤细菌活性,两者结合能有效实现基因转移的长时间原位观测,能够区分抗性基因的水平转移和垂直转移.结果表明:垂直转移是污泥菌群中抗性基因的主要转移方式,菌群纵向转移速率与其厚度有关,菌群内部转移率较高,基因转移速率为0.24～0.29 h~(-1).     

亚热带河口陆基养虾塘水体CDOM三维荧光光谱平行因子分析

利用三维荧光光谱平行因子分析(EEMs-PARAFAC)技术,对我国亚热带地区闽江、木兰溪、九龙江河口滨海陆基养虾塘水体的有色溶解性有机质(CDOM)进行了组分及来源分析.研究表明从养虾塘水体CDOM荧光光谱中解析出4个有效PARAFAC荧光组分,包括2种类蛋白质物质和2种类腐殖酸物质,其中类蛋白质组分是河口陆基养虾塘水体中CDOM的主要组成部分.水体的荧光指数FI和自生源指标BIX表明河口区滨海陆基养虾塘水体中CDOM的强自生来源贡献.而腐殖化指标HIX表明养殖塘水体具有弱腐殖化特征.类蛋白质组分与类腐殖质组分之间可能具有相同的来源属性和地化行为,盐度与CDOM呈现极显著负相关,而DOC与CDOM中类腐殖质组分(C2、C3)呈现显著正相关.本研究为进一步揭示养虾塘水体CDOM的光化学性质提供了科学依据.     

Forest Insect Pest Management and Forest Management in China: An Overview

According to the Seventh National Forest Inventory (2004–2008), China’s forests cover an area of 195.45 million ha, or 20.36% of the total land area. China has the most rapidly increasing forest resources in the world. However, China is also a country with serious forest pest problems. There are more than 8,000 species of potential forest pests in China, including insects, plant diseases, rodents and lagomorphs, and hazardous plants. Among them, 300 species are considered as economically or ecologically important, and half of these are serious pests, including 86 species of insects. Forest management and utilization have a considerable influence on the stability and sustainability of forest ecosystems. At the national level, forestry policies always play a major role in forest resource management and forest health protection. In this paper, we present a comprehensive overview of both achievements and challenges in forest management and insect pest control in China. First, we summarize the current status of forest resources and their pests in China. Second, we address the theories, policies, practices and major national actions on forestry and forest insect pest management, including the Engineering Pest Management of China, the National Key Forestry Programs, the Classified Forest Management system, and the Collective Forest Tenure Reform. We analyze and discuss three representative plantations—Eucalyptus, poplar and Masson pine plantations—with respect to their insect diversity, pest problems and pest management measures.     

矿山地质环境安全评估的Bayes判别分析法及应用

从矿山地质环境的实际特性出发,应用Bayes判别分析方法评估矿山地质环境问题。选用13项影响矿山地质环境的区域地质条件、环境现状、矿产资源开发规划、生态恢复治理状况的具体评估指标,以大量实测资料作为学习样本,并按各总体的样本比例确定先验概率,建立了矿山地质环境评估的Bayes判别分析模型。将该模型用于预测样本的评估中,采用回代估计法对判别结果进行验证,误判率为零,判别结果和实际一致。研究结果表明,Bayes判别分析模型是一种结构稳定、判别准确率很高的评估模型,能够用于矿山地质环境的评估。