Risk assessment of polycyclic aromatic hydrocarbons in the West Port semi-enclosed basin (Malaysia)

Sediment samples collected from the West Port, the west coastal waters of Malaysia, were analyzed by standard methods to determine the degree of hydrocarbon contamination and identify the sources of polyaromatic hydrocarbons (PAHs). Concentrations of PAHs in the port sediments ranged from 100.3 to 3,446.9 μg/kg dw. The highest concentrations were observed in stations close to the coastline, locations affected by intensive shipping activities and industrial input. These were dominated by high-molecular-weight PAHs (4–6 rings). Source identification showed that PAHs originated mostly pyrogenically, from the combustion of fossil fuels, grass, wood, and coal or from petroleum combustion. Regarding ecological risk estimation, only station 7 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the West Port.     

盐湖丰产元素与Zintl化合物(续完)

Zintl化合物是以Edward Zintl命名的化合物,是一类由电正性的碱金属或碱土金属与电负性的13族或14族元素形成的特殊金属间化合物。其价键模式可以是离子键、金属键和共价键共存,其中的准金属可以共价键的形式形成各种形式的离子簇,因而其结构复杂多样。这类化合物的部分阴离子簇不仅具有稳定的笼状、层状和链状结构,并且具有特殊的光、电、磁等性能,使得在半导体、催化、电极材料等方面都有应用的前景和发展潜力。介绍了几个特殊Zintl化合物体系,盐湖丰产元素在Zintl化合物中的作用,指出了含有盐湖丰产元素的Zintl化合物的应用前景和方向。     

盐湖丰产元素与Zintl化合物(续一)

Zintl化合物是以Edward Zintl命名的化合物,是一类由电正性的碱金属或碱土金属与电负性的13族或14族元素形成的特殊金属间化合物。其价键模式可以是离子键、金属键和共价键共存,其中的准金属可以共价键的形式形成各种形式的离子簇,因而其结构复杂多样。这类化合物的部分阴离子簇不仅具有稳定的笼状、层状和链状结构,并且具有特殊的光、电、磁等性能,使得在半导体、催化、电极材料等方面都有应用的前景和发展潜力。介绍了几个特殊Zintl化合物体系,盐湖丰产元素在Zintl化合物中的作用,指出了含有盐湖丰产元素的Zintl化合物的应用前景和方向。     

Predictive environmental impact assessment of total petroleum hydrocarbons in petrochemical wastewater effluent and surface sediment

The contamination level of total petroleum hydrocarbons (TPH) in wastewater and surface sediment samples from the Petrochemical Special Economic Zone (PETZONE) and adjacent coastal area in Musa Bay (in Northwest of Persian Gulf) was examined. Concentrations of TPH in the Musa Bay sediments ranged from 16.48 to 97.15 µg/g dry weight (dw) with average value of 48.98 ± 30.36 µg/g dw. The highest concentrations were estimated in stations close to the coastline, locations affected by intensive petrochemical discharges and shipping activities. The average TPH concentration in the PETZONE wastewater effluent samples was 5.22 mg/L, with a range of 0.06–35.33 mg/L. Regarding environmental impact assessment, the concentration of TPH was lower than the wastewater effluent discharge standard at most of the monitoring stations inside PETZONE companies, with the exception of stations 15, 16 (Imam Khomeini petrochemical company 1, 2) and 17 (Razi petrochemical company). These stations were considered as moderate environmental aspects, suggesting that concentration of TPH in the wastewater effluents of these petrochemical companies could be considered as contaminants of concern in the PETZONE area.     

Heavy metal contamination in water and sediment of the Port Klang coastal area, Selangor, Malaysia

This investigation presents the temporal and spatial distribution of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Hg, and Zn), in water and in sediments of Port Klang, Malaysia. Water and sediment samples were collected from 21 stations at 3-month intervals, and contamination factor $ (C_{\text{f}} ) $ and contamination degree $ (C_{\text{d}} ) $ were calculated to estimate the contamination status at the sampling stations. Cluster analysis was used to classify the stations based on the contamination sources. Results show that concentrations of As, Cd, Hg, and Pb in sediment and As, Cd, Hg, Pb, Cr, and Zn in water were significantly higher than the background values at which these metals are considered hazardous. The main sources of heavy metal contamination in Port Klang were industrial wastewater and port activities.     

The Response of Macrobenthic Communities to Environmental Variability in Tropical Coastal Waters

The relative contributions of spatial and temporal fluctuations are different in shaping natural communities in a tropical coastal/estuarine system. Understanding how coastal communities respond to these fluctuations is still equivocal, and thus, available data are rare. Here, multiple analytical approaches were used to identify key spatial and temporal factors, and to quantify their relative roles in shaping a macrobenthic community through space (contamination degree, physical parameters, and sediment characteristics) and time (climatic factors, season, and year). A dataset of eight sampling times was analyzed over a period of 2 years, in which macrobenthic species abundances were sampled. A total of 33 species were identified, including 18 bivalves, 5 gastropods, and 4 crustaceans. The other taxa were less diverse. The results show that there were no significant temporal changes of macrobenthic community structure, but spatial changes were significant and synchronized with environmental factors (i.e., sediment characteristics, water depth, and the distance from anthropogenic sources). This study demonstrates that spatial factors played a primary role in structuring of macrobenthic assemblages, whereas the influence of temporal factors appeared less across geographically distinct sites. Thus, temporal variation of a coastal macrobenthic community appears to be controlled by partly different processes at different scales.     

STUDIES ON THE POTENTIAL OF GRAIN PRODUCTION IN THE NORTHEAST REGION OF CHINA

Northeast region covers an area of 1.24 million km, making up 12.9% of the total area of China, with a population of 103 million, 9.9% of the total population of China. The grain commodity rate is over 35%. It is one of the very important regions of grain production in China. As population and grain demand unceasingly increase, the potential of grain production, and the commodity grain provided for the nation are the major problems about grain consumption and distribution in the future. And they directly affect the realization of national planning objective of grain production.The analysis of grain production conditions and history indicates that: 1) The increase of total grain output is mainly dependent on the increase of grain yield per unit area, but not the enlargement of grain sown area. 2) The factor to affect grain yield per unit area are materials input, correct policies, yearly climatic variation. 3) By the year 2000 and 2010 the total grain output in this region will be respectively 66.16-66.2