"南海贻贝观察":广东沿海牡蛎体中Zn含量水平及其变化趋势

为了了解广东沿海重要养殖水域Zn含量水平变化趋势,1989～1997年间实施"南海贻贝观察"计划对广东12个地点牡蛎体的Zn含量进行了连续监测.广东沿海牡蛎体Zn含量范围为50.4×10-6～768×10-6,总平均值为245×10-6,总体上属清洁～微污染水平.牡蛎体Zn含量的海域分布格局呈珠江口海区＞粤东海区≥粤西海区.1989～1991年,广东沿海牡蛎体Zn含量呈上升趋势,此后略微下降,1994～1997年间牡蛎体Zn含量虽有波动,但年际间没有明显差异.     

防治船舶在珠澳水域油污染的几个问题

系统分析了船舶在珠澳水域造成的油污染情况，从现场管理的角度，结合近10年来发生的油污事件，针对不同污染途径找出了防治工作中的一些不足，并对水质分析、油品鉴定、防治重点、防治基金分配等方面提出一些建议。     

The As-Contaminated Elqui River Basin: a Long Lasting Perspective (1975–1995) Covering the Initiation and Development of Au–Cu–As Mining in the High Andes of Northern Chile

The Elqui watershed (northern Chile) constitutes a highly contaminated river system, with arsenic exceeding by up to three orders of magnitude the average for river waters. There are three main reasons that explain this contamination: (1) the regional geology and hydrothermal (mineralizing) processes that developed in this realm during Miocene time; (2) the later unroofing–erosion–oxidation–leaching of As–Cu rich sulfide ores, a process that have been taking place for at least 10,000 years; and last but not least (3) mining activities at the high-altitude (>4000 m above sea level) Au–Cu–As El Indio mine, from the late 1970s onwards. The El Indio mineral deposit hosted large veins of massive sulfides, including the important presence of enargite (Cu₃AsS₄). The continuous natural erosion of these veins and their host rocks (also rich in As and Cu) during Holocene time, led to important and widespread metal dispersion along the river system. During the studied pre mining period (1975–1977), the high altitude river Toro waters already showed very large As concentrations (0.36–0.52 mg l⁻¹). The initiation of full scale mining at El Indio (1980 onwards) led to an increase of these values, reaching a concentration of 1.51 mg l⁻¹ As in 1995. During the same year other rivers of the watershed reached peak As concentrations of 0.33 (Turbio) and 0.11 mg l⁻¹ (Elqui). These figures largely exceed the USEPA regulations for drinking water (0.01 mg l⁻¹ As), and about 10% of the total As data from the river Elqui (and 70% from the river Turbio) are above the maximum level allowed by the Chilean law for irrigation water (0.1 mg l⁻¹ As).     

WATER QUALITY IN THE RED SEA COASTAL WATERS (EGYPT): ANALYSIS OF SPATIAL AND TEMPORAL VARIABILITY

In order to provide a background picture of the water quality of the Egyptian Red Sea a number of hydrological and chemical parameters have been measured bimonthly in 2000. Few data are available on this area, which is apparently subjected to an increasing human impact due to recreational (swimming and diving), industrial (mainly phosphate shipping and industry) and fishing/harbor activities. The results of the present study indicate that changes in the salinity and pH were not significant with highly oxygenated seawaters. The levels of suspended solids (as total suspended matter, TSM) and chlorophyll-a (Chl-a) were generally low and showed an homogeneous distribution in the study region. The ratio of chlorophyll-a to total suspended matter concentrations increased between November and March and decreased from May to September. Chlorophyll-a was significantly correlated with transparency and total suspended matter concentrations in July, September and November. Nitrogen, phosphorus and reactive silicate concentrations were generally low, and allowed classifying the Egyptian Red Sea coastal water as oligotrophic to mesotrophic. The middle region of the study area, which was located between Safaga and Qusair displayed relatively high phosphate contents when compared with other coastal areas. The high values of N:P ratios indicate that PO 4 -P is the limiting factor for phytoplankton growth in the Red Sea coastal waters, with the possible exception of the middle region. Significant relationships were found between chlorophyll-a concentrations and nutrient levels in different sampling periods. Spatial distribution patterns of the studied variables revealed that productivity of the Red Sea coastal waters is mostly controlled by phosphate concentrations, salinity, temperature and dissolved oxygen.     

深圳海域引发赤潮生物种类的演变及其原因浅析

从1981年至2001年,深圳海域共记录发生赤潮85起,引发这些赤潮的生物种类约有36种。在这20余a间,引发赤潮的生物种类的演变趋势是:(1)引发赤潮的生物种类的多样性不断增高;(2)在引发赤潮的生物种类中常见种类逐渐减少,罕见种类逐渐增多;(3)在引发赤潮的生物种类中硅藻种类正逐渐减少,甲藻类及针胞类种类明显逐渐增多。据初步分析认为,这种演变趋势与深圳海域近20a来因沿海地区社会经济发展引起的入海污染物构成变化趋势有关,并且与全球不断演变的总趋势是相一致的。     

两种原子吸收法测定环境水样中镍的比较

用加热浓缩-火焰原子吸收光谱法和石墨炉-原子吸收光谱法对环境水样中的镍进行了比较测定,结果表明,两种方法测定镍的各项指标均在要求范围,两种方法测定结果的相对误差均＜7.1%,表明两种方法可以视为等效方法,作用可以相互替补使用.