Spatial distribution and source identification of persistent pollutants in marine sediments of Hong Kong

A data matrix, obtained during a 3-year monitoring period (2007–2009) from 45 sampling sites in Hong Kong marine, was subjected to determine the spatial characterization and identify the sources of main pollutants. Indicator analyses indicated that polycyclic aromatic hydrocarbons (PAHs), nickel, manganese, and arsenic (As) were at safe levels. Five heavy metals (zinc, lead, cupper, cadmium, chromium (Cr)) were moderate to severe enrichment at some sites. Inner Deep Bay and Victoria Harbor were considered as hot spots for PAHs and the heavy metals, while Tolo Harbor was highly polluted by the heavy metals. Cluster analysis classified the 45 sampling sites into three groups, representing different pollution levels. Principal component analysis/factor analysis identified four principal components (PCs) and explained 84.9 % of the total variances, standing for persistent pollution, N factor, P and Cr factor, and As factor, respectively. Group A was highly polluted by persistent pollution, group B was the less polluted group, and subgroup B1 was less affected by PC3 and PC4 than subgroup B2. Group C, considered as the moderately polluted group, was greatly affected by N factor or persistent pollution, while subgroup C2 received more N pollution than subgroup C1.     

Global Trend of Low-carbon Economy and China's Responses

Based on the analysis on the global economic crisis,climate change crisis and their mutual underlying reasons,the authors believe that low-carbon economy has become an inevitable choice to break through the dual crises,coordinate the economic development,and protect the global climate.The global trend of low-carbon economy finds expression in Green Recovery currently,while,in a long run,it will give rise to a new pattern of world competition in politics,economy,technology,trade and finance.The impact of the...     

Preparation of Fish-scale Gelatins by Mild Hydrolysis and Their Characterization

This study characterized gelatins prepared by mild hydrolysis of freshwater fish-scale collagen. Among the selected types of protease (trypsin, neutral protease, papain, and alkaline protease), alkaline protease was proven to be the most effective enzyme for gelatin extraction by hydrolysis of fish-scale collagen. The optimum hydrolysis conditions were as follows: reaction time, 6 h; temperature, 50 °C; pH 9; and enzyme amount, 3 % (w/w). Under these optimum hydrolysis conditions, the gelatin yield reached 48.1 % (w/w). The gelatins prepared by alkaline protease hydrolysis show higher emulsion activity and lower emulsion stability indices than those prepared by water extraction.     

Medical waste management in China: A case study of Nanjing

Medical waste management is of great importance due to its infectious and hazardous nature that can cause undesirable effects on humans and the environment. The objective of this study was to analyze and evaluate the present status of medical waste management in the light of medical waste control regulations in Nanjing. A comprehensive inspection survey was conducted for 15 hospitals, 3 disposal companies and 200 patients. Field visits and a questionnaire survey method were implemented to collect information regarding different medical waste management aspects, including medical waste generation, segregation and collection, storage, training and education, transportation, disposal, and public awareness.The results indicated that the medical waste generation rate ranges from 0.5 to 0.8 kg/bed day with a weighted average of 0.68 kg/bed day. The segregated collection of various types of medical waste has been conducted in 73% of the hospitals, but 20% of the hospitals still use unqualified staff for medical waste collection, and 93.3% of the hospitals have temporary storage areas. Additionally, 93.3% of the hospitals have provided training for staff; however, only 20% of the hospitals have ongoing training and education. It was found that the centralized disposal system has been constructed based on incineration technology, and the disposal cost of medical waste is about 580 US$/ton. The results also suggested that there is not sufficient public understanding of medical waste management, and 77% of respondents think medical waste management is an important factor in selecting hospital services.The problematic areas of medical waste management in Nanjing are addressed by proposing some recommendations that will ensure that potential health and environmental risks of medical waste are minimized.     

新疆哈密马庄山金矿区次火山岩及其地球化学特征

马庄山金矿区位于星星峡一卡瓦布拉克地块、古生代岛弧东段北侧活动大陆边缘，有多种火山宕、次火山岩和侵入岩，而与金矿成矿关系最为密切的是海西中、晚期次火山岩。该矿区次火山岩有花岗闪长斑岩、石英斑岩、花岗斑岩、隐爆角砾岩（简称花岗质岩）和辉绿岩。因此，在区域地质背景和矿区地质特征分析基础上，着重对次火山岩及其地球化学特征进行系统研究，结果认为．该矿区花岗质岩为高硅富钾贫铝钙碱性同熔（1）型花岗岩类，岩浆源区来自中下地壳；辉绿岩则为富钠碱性正常型基性岩类，岩浆源区来自下地壳。前者含Co、Pb、Zn、Sn、As、Bi、W、Mo、An、Ag、Tc等元素较高，有重要找矿前景；后者含Ba、Pb、Zn、Tl、As、Bi、Au、Ag、Tc等元素较高，也可为成矿提供物源。这些认识，对该区次火山岩特征、性质、成矿关系和构造背景，以及进一步找矿都有重要理论和实践指导意义。     

土地利用变化对贵州印江喀斯特小流域水体DIC含量及δ~(13)C_(DIC)的影响

以印江流域水体为研究对象,分别于2014年夏季和冬季采集印江河主干与支流表层水样品,测定并分析其基本物理化学参数、主量离子浓度和溶解性无机碳(DIC)含量及其碳同位素组成(δ~(13)C_(DIC)),结合流域内不同的气候条件和土地利用强度与方式等生态环境条件,对表层水体中DIC的来源及其时空变化特征进行探讨。结果表明:印江河流域表层水p H值呈中性到碱性,水化学组成主要受碳酸盐岩风化的控制,阳离子主要以Ca~(2+)、Mg~(2+)为主,阴离子主要以HCO-3为主,而且主量离子在冬夏季表现出较为显著的差异。印江河流域干、支流水体DIC和主量离子含量向下游总体呈现递增趋势,并随季节呈现夏低冬高的变化趋势,可能与研究区水体上游土地利用强度低而下游存在大量的农耕用地以及当地冬夏季降雨量差异有关。相比之下,印江河流域干流水体δ~(13)C_(DIC)均值为-10.39‰、支流水体δ~(13)C_(DIC)均值为-8.29‰,差异相对显著,反映了作为源头支流水体主要受碳酸盐岩风化影响,支流汇入干流水体过程周边土地利用强度增大、方式多样,影响较为明显。而且该流域干、支流水体δ~(13)C_(DIC)的季节性差异显著,支流水体DIC主要由于水-岩交换在冬季更加富集13C,而干流水体DIC则主要由于生物量效应在夏季相对富集13C,极有可能与当地土地利用强度和方式的季节性变化有关。     

Analysis and Modeling on the Spatial Structure of Urban Land Use: A Case of Jinan, China

Based on the data of urban land use obtained by remote sensing interpretation from aero images in 1986 and 2004, the spatial structure of Jinan is studied in this paper with the method of Geographic Information System (GIS). According to the proportion of land for residence, industry and commerce, the urban district can be distinguished into three rings. Compared with the traditional theory of the ring structure in Western coun- tries, they have many distinctive characteristics. The main func- tions of the inner ring include residence, business and banking, but the proportion of residential land (more than 50%) is considerably higher than that of the cities in Western countries. The land proportion for residence and industry in the intermediate ring is equal on the whole. The main land of the outside ring is for industrial use. From 1986 to 2004, great changes have taken place on the land proportion of different types of use. In the inner ring, the land for residential and industrial use has shrunk much while the land for commercial use has increased. In the intermediate ring, the changes of the three types of land use were not very much and the temporal variation was relatively stable. On the contrary, the structure in the outside ring varies acutely. Though most of it is also for industrial use, the proportion of residential land has in- creased much. The three rings can also be divided into several sectors respectively, according to the function of land use clusters. New trends and mechanisms of the changes of land use impacting the urban structure were proposed in the end of the paper.