环渤海近岸海域表层沉积物及底栖生物中PBDEs的赋存特征及富集行为

多溴联苯醚(PBDEs)作为一种新型的持久性有机污染物,在海洋环境中广泛存在,研究PBDEs在不同介质中的赋存状态对于理解其环境行为及归趋具有重要的意义。通过采集不同区域沉积物及生物样品,考察了PBDEs在环渤海近岸海域表层沉积物及底栖生物中的含量及空间分布特征、污染模式及生物-沉积物富集因子。结果表明,环渤海沿岸表层沉积物中PBDEs总量(Σ10PBDEs)的浓度范围在0.446~26.8 ng·g-1(干重,dw)之间,中值为1.02 ng·g-1(dw),底栖生物中PBDEs(Σ9PBDEs)的浓度范围为0.053~9.90 ng·g-1(dw),中值为1.25 ng·g-1dw;沉积物中BDE-209为最主要的单体,平均丰度达到90.5%,生物体中主要以低溴代BDEs为主,其中单体BDE-47的含量最高,平均丰度范围为43.2%~49.7%;沉积物和生物中PBDEs的含量在空间上存在显著的差异,其中莱州湾和锦州附近区域的结果明显高于其他区域;5种不同的底栖生物对PBDEs均表现出一定的生物富集性,其中∑9PBDEs的BSAF值按从大到小的顺序为菲律宾蛤仔(0.43~4.06,mean=1.19)紫贻贝(0.34~2.86,1.03)四角蛤蜊(0.17~1.95,0.82)麻蛤(0.13~2.33,0.61)牡蛎(0.09~1.20,0.52)。辛醇水分配系数(log KOW)与不同物种BSAF值的相关性分析结果表明,除BDE-17单体外,其他单体的BSAF值表现出随log KOW的升高而下降的趋势。     

基于广义极值分布的流化床压力波动风险预警

为预警气泡运动所引起的流化床粉煤气化压力波动风险,提出预测压力波动极值以及压力波动重现水平的方法;首先采用自相关分析法将压力波动母样本数据合理分段,再用区间极值法统计子样本的压力波动极值数据,以广义极值(GEV)分布方法建立GEV分布模型和Gumbel分布模型,并经过模型诊断选择最优模型;然后通过子样本与母样本的参数关...     

我国地方生态环境规划院（所）建设情况与发展展望

环境规划队伍是环保铁军的重要一员,随着生态文明建设和生态环境保护工作不断深入,我国环境规划院（所）建设逐步从无到有,人才队伍逐步发展壮大,支撑生态环境保护综合决策能力日益提高。本研究面向各省（区、市）及部分副省级城市环境规划院（所）开展了问卷调查,分析我国环境规划研究队伍和机构建设现状,围绕管理制度、市场发展、人才培养、交流合作等方面对未来发展进行展望。     

模糊综合评价在焦化企业安全评价中的应用

结合焦化企业生产单元事故发生的特点,运用模糊综合评判理论,对焦化企业生产单元安全系统进行分析。综合考虑影响焦化企业生产单元安全的各种因素,确定焦化企业生产单元安全评价指标体系。采用层次分析法确定权重可以保证得出的焦化企业生产单元安全模糊综合评价模型更具有有效性。     

Function Approximation and Documentation of Sampling Data Using Artificial Neural Networks

Biodiversity studies in ecology often begin with the fitting and documentation of sampling data. This study is conducted to make function approximation on sampling data and to document the sampling information using artificial neural network algorithms, based on the invertebrate data sampled in the irrigated rice field.Three types of sampling data, i.e., the curve species richness vs. the sample size, the curve rarefaction, and the curve mean abundance of newly sampled species vs.the sample size, are fitted and documented using BP (Backpropagation) network and RBF (Radial Basis Function) network. As the comparisons, The Arrhenius model, and rarefaction model, and power function are tested for their ability to fit these data. The results show that the BP network and RBF network fit the data better than these models with smaller errors.BP network and RBF network can fit non-linear functions (sampling data) with specified accuracy and don't require mathematical assumptions. In addition to the interpolation, BP network is used to extrapolate the functions and the asymptote of the sampling data can be drawn. BP network cost a longer time to train the network and the results are always less stable compared to the RBF network. RBF network require more neurons to fit functions and generally it may not be used to extrapolate the functions. The mathematical function for sampling data can be exactly fitted using artificial neural network algorithms by adjusting the desired accuracy and maximum iterations. The total numbers of functional species of invertebrates in the tropical irrigated rice field are extrapolated as 140 to 149 using trained BP network, which are similar to the observed richness.     

A Long-Term Forecast Analysis On Worldwide Land Uses

Abstact More and more lands worldwide are being cultivated for food production while forests are disappearing at an unprecedented rate. This paper aims to make a long-term forecast on land uses worldwide and provide the publics, researchers, and government officials with a clear profile for land uses in the future. Data of land uses since 1961 were used to fit historical trajectories and make the forecast. The results show that trajectories of land areas can be well fitted with univariate linear regressions. The forecasts of land uses during the coming 25 years were given in detail.Areas of agricultural land, arable land, and permanent pasture land worldwide would increase by 6.6%, 7.2%, and 6.3% respectively in the year 2030 as compared to the current areas. Permanent crops land area all over the world is forecasted to increase 0.64% by 2030. By the year 2030 the areas of forests and woodland, nonarable and nonpermanent land worldwide would decrease by 2.4% and 0.9% against the current areas. All other land area in the world would dramatically decline by 6.4% by the year 2030.Overall the land area related to agriculture would tend to decrease in developed countries, industrialized countries, Europe, and North and Central America. The agriculture related land area would considerably increase in developing countries, least developed countries, low-income countries, Asia, Africa, South America, etc.Developing countries hold larger total land area than developed countries. Dramatic and continuous growth in agricultural land area of developing countries would largely contribute to the expected growth of world agricultural land area in the coming years. Population explosion, food shortage and poverty in the world, especially in developing countries, together caused the excessive cultivation of land for agricultural uses in the past years. Increasing agricultural land area exacerbates the climate changes and degradation of environment. How to limit the growth of human population is a key problem for reducing agricultural land expansion. Development and use of high-yielding and high-quality crop and animal varieties, diversification of human food sources, and technical and financial assistance to developing countries from developed countries, should also be implemented and strengthened in the future in order to slow down or even reverse the increase trend of agricultural land area. Sustainable agriculture is the effective way to stabilize the agricultural land area without food shortage. Through various techniques and measures, sustainable agriculture may meet the food production goals with minimum environmental risk. Public awareness and interest in sustainable agriculture will help realize and ease the increasing stress from agricultural land expansion.     

臭氧组合工艺去除饮用水源水中有机物的效果

研究由臭氧氧化、生物处理、常规处理和活性炭吸附组成的臭氧组合工艺以及各单元工艺对饮用水源水中有机物的去除效果 .结果表明 ,由于预臭氧对有机物的氧化 ,减小了有机物的分子量 ,增加了可生物降解的有机物 ,从而强化了后续的生物处理和活性炭对有机物的去除 .整个工艺对有机物的控制能力很好 ,UV2 54、DOC、BDOC、AOC、THMFP和 HAAFP的去除率分别达到 95.1%、92.5%、98.4%、85.8%、63.1 %和 89.1% .预臭氧-生物陶粒的预处理对各有机物的去除效果在 50%左右 ,常规处理对各有机物的去除不尽相同 ,后臭氧 -活性炭对有机物的去除达到了 60 %左右 .     

我国10城市冬季大气颗粒物中多环芳烃污染及呼吸暴露风险评价

大气中颗粒物和多环芳烃对环境与人体健康危害较大,已引起社会各界的广泛关注。以我国10个城市2013年12月和2014年1月大气中空气动力学直径小于10μm的颗粒物(PM10)为研究对象,采用硅胶-氧化铝层析柱净化分离、气质联用仪分析的方法测定了27种多环芳烃(PAHs)的浓度水平,分析其谱分布及空间分布,并通过呼吸暴露途径估算了癌症病发增量(ILCRs)和人群归因危险度百分比(PAF)。结果表明,27种物质的总浓度为13.72~2 002 ng·m-3;在10个城市中晋中总浓度最高,厦门最低。PAHs空间污染水平呈现北方高于南方、东部沿海城市浓度相对较低的趋势。温度与总浓度有相关性。在27种PAHs中,占主导地位的单体为荧蒽(FLA,7.56%~19.8%),芘(PYR,6.72%~13.8%),艹屈(CHR,12.8%~19.6%)和苯并(k)荧蒽(Bk F,8.59%~15.5%),4者占到多环芳烃总浓度的42.1%~64.3%。根据研究区域苯并[a]芘(Ba P)人口加权浓度估算ILCRs范围为8.94×10-6~4.77×10-4,据此计算的PAFs为0.487%~13.2%,均值为3.44%,高于全国平均水平1.6%。上述研究结果为大气颗粒物中PAHs的研究提供重要的数据基础。     

Reduction of nitrobenzene with sulfides catalyzed by the black carbons from crop-residue ashes

In this paper, three types of black carbons (BCs) named R-BC, W-BC, and C-BC were derived from rice straw ashes, wheat straw ashes, and corn straw ashes, respectively. Under room temperature and in an anaerobic aqueous solution, these three types of BCs could catalyze the reduction of nitrobenzene (NB) by sulfides rather than only act as the superabsorbent. The catalytic activities of BCs derived from different crop-residue ashes were very different and in the order of R-BC > W-BC > C-BC, since the reaction rate constants (k _obs) of NB with the BCs in the presence of 3 mM sulfides were 0.0186, 0.0063, and 0.0051 h^?1, respectively. The key catalytic active sites for NB reduction were evaluated, with four types of modified BCs and two types of tailored graphite as the model catalysts. The results indicated that BCs probably had two types of active sites for NB reduction, the microscopic graphene moieties and the surface oxygen functional groups. Since the sulfides and BCs often coexist in the environment, this BC-catalyzed reduction technology of NACs may be applied as an in situ remediation technique without the need for reagent addition.     

Impacts of Nomad Sedentarization on Social and Ecological Systems at Multiple Scales in Xinjiang Uyghur Autonomous Region,China

China’s government is now promoting the Nomad Sedentarization Project (NSP) in large areas of grassland as a solution for ecological restoration and poverty alleviation. To examine the effects of this policy, we conducted in-depth interviews at two of the project’s sites and examined the social and ecological systems at village, county, and catchment scales in Jinghe County of Xinjiang. We found that (1) the NSP in one village greatly improved the household standard of living and changed their resource utilization modes; (2) the success in this village can be attributed to resources imported from the social and ecological systems at larger scales, and could not be repeated in a second nearby village with different constraints; and (3) the NSP is poorly adapted to local ecosystem characteristics, and may therefore have negative impacts at larger scales. To avoid these problems, holistic assessments are necessary to judge the NSP’s impacts on social and ecological systems at multiple scales, and the program must be implemented cautiously to account for the potential risks in ecologically vulnerable areas.