长江口最大浑浊带潮周期内悬浮物中的重金属

In order to discuss the content distributions and fluxes of heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary,the contents of heavy metals(Zn,Pb,Cd,Co and Ni) have been analyzed.During a tidal cycle,the average contents of heavy metals are in the order of ZnNiPbCo àCd.The average contents in ebb tide are generally higher than that in flood tide.However,at the inshore Sta.11,influenced by the contamination from the nearby waste treatment plant,the average contents of Zn and Ni in flood tide are higher than those in ebb tide and at the offshore Sta.10,the content of Cd in flood tide higher than that in ebb tide due to marine-derived materials.The five heavy metals,mainly terrigenous,are transported towards east-northeast,and settle down with suspended matters in the area between Sta.11 and Sta.10.Influenced by marine-derived materials,the flux value of Cd does not alter significantly with obviously changing in flux direction towards northwest.The source of heavy metals,the salinity of water and the concentration of suspended matters are the main factors controlling the content distributions of heavy metals during a tidal cycle.There is a positive correlation between the contents of heavy metals(Zn,Pb,Co and Ni) and the salinity of water,while the opposite correlation between the contents and the concentrations of suspended matters.Because of marine-derived materials,the content of Cd is not correlated with the concentration of suspended matters and the salinity of water.     

Chemical Associations of Heavy Metals in the Sediments near Bailonggang Sewage Discharge Outlet of Shanghai

The five chemical associations ofheavy metals have been extracted continuously using the Tessier extracting method.Results show that Cu,Pb,Fe,Zn and Cr in the sediments are mainly distributed in residual fraction,while the major chemical association of Mn is carbonates.Carbonate heavy metals are converted into Fe-Mn oxides in autunm.And in the low tidal flat,after carbonates have changed into ionic heavy metals,some of the elements are transported to the overlying water,Cu,Pb,Fe and Mn have good correlations with each other,and Zn,Cr also show their similarity of chemical behavior in the sediments.     

The pathway and fate of the heavy metal mixture in Xiamen marine experiment enclosures

The pathway and fate of heavy metals were studied in 10m3 enclosures at Xiamen Bay in 1985. The dissolved metals added are removed rather quickly during the first days, and their half-removal times ( t1/2) (d) are as follows: Pb 5. 4-5. 8, Hg 6. 7-14, Zn 11-22, Cu 16 - 29, and Cd 30-89. Zinc is transferred biologically to particles during phytoplankton bloom. The main Fate of added metals after 27 days is as follows; over 80% Cd and 60% Cu remain in dissolved phase, more than 60% Pb and 50% Hg transfer to settling settlement, while Zn is equally distributed in dissolved phase and settling settlement. The wall uptake is less than 2% of the total metals added. Organic materials play an essential role in the partition and the transfer of heavy metals in water column. Terrigenous and autochthonous particles show different affinities to different metals. Most heavy metals associate weakly with zooplankton. The Binding of Cd, Pb, Zn and Cu to the particles shows distinctive features related to the diagenetic     

Heavy metals in Changjiang estuarine and offshore sediments: responding to human activities

The Changjiang (Yangtze) estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions.Distributions of heavy metals show typical banded diffusion pattern,with high concentrations near the river mouth and following a decreasing trend in the offshore direction.According to chemical fractions,Fe/Mn oxide fraction is the major non-residual fraction in the Changjiang estuarine and offshore sediments.Higher percentage of non-residual fraction of Pb implies that,the industrial contaminations transported via the atmosphere and river input,may affect the non-residual fraction of heavy metals.Over past fifteen years,the concentration of Pb normalizing to Al presents significant increasing trend,corresponding to the effect of human activities.By comparison of heavy metals fractions in 2003 to 2006,it has been realized that increasing water and sediment may cause a higher percentage non-residual fraction of Cu in the southern part of offshore muddy sediments.     

Speciation, distribution, and potential ecological risk assessment of heavy metals in Xiamen Bay surface sediment

Based on the survey of surface sediment in Xiamen Bay in October 2011, the speciation, distribution, and potential ecological risk assessment of heavy metals （Cu, Pb, Zn, Cd, and Cr） in this area were studied us-ing the sequential extraction method and ecological risk assessment method. The results indicated：（1） the total concentrations of these heavy metals were influenced by runoff, industrial wastewater, and sewage, and were all higher in the coastal area than the offshore area while the highest area of Pb was a little far-ther away from the coastal water due to atmosphere deposition;（2） sequential extractions suggested that Cu was mainly composed with residual and Fe/Mn-oxide bound fractions, Pb was bound to Fe/Mn-oxide, Zn and Cr were dominated by residual, and Cd bound to exchangeable and carbonate fractions; （3） the order of migration and transformation sequence was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr and the degree of pollution was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr;and （4） the ratios of the secondary and primary phases showed that Zn and Cr were both clean, Cu may be polluted, Pb was moderately polluted, while Cd was heavily polluted.     

THE BEHAVIOUR OF 65Zn IN ARTIFICIAL MARINE MICROHABITAT

The concentration of 65Zn under artificial conditions in suspended matter, sediment, algae, and excretion as well as its distribution in the organs of fish (Tilapia mossambia), prawn (Penaeus peni-cillatus), clam (Area granosa), clam (Cyclina sinensis) are studied. The results show a high concentration factor of suspended matter, with a dynamic equilibrium of concentration by lagea arrived after two days. The concentration factor of 85Zn in the intestines of fish, prawn, clam and gills of clam are very high, and their excretive rate is rapid. It shows that the intestines and gills are critical organs of 65Zn concentration. The content of 65Zn in nucleic acid is highest, and is higher in RNA than in DNA, while that in organic acid is lowest.     

THE EFFECT OF FOUR HEAVY METALS ON THE GROWTH RATE AND CHLOROPHYLL CONTENT OF Chaetoceros muelleri LEMMERMANN

Chaetoceros muelleri Lemmermann was cultured in solution of different concentrations of Cu2 , Pb2 , Zn2 and Cd2 , and in mixtures of any two of them. After 6 days the effect of these heavy metal cations on the growth rate and chlorophyll contents of the diatom were determined and an Opton microscope was used to observe the morphology and size of the cells.The experimental results show that the effects of toxicity of these four heavy metals on Chaetoceros muelleri are: Cu2 >Pb2 >Zn2 >Cd2 . However, the cells did not differ significantly in their morphology and size from the controled ones.In any of the mixed metals cultures, its growth rate came close to and was higher than that of the single metal culture of higher concentration.     

GEOCHEMISTRY OF ABYSSAL SEDIMENT IN THE PACIFIC OCEAN

The contents of Fe, Mn, Cu, Co, Ni, Pb and Zn in the seaiment associated with manganese nodules from the Northern Central Pacific Ocean and in their acid-soluble fractions were determined and correlations among the elements and between the trace metals and environmental parameters were discussed. It has been found that the contents of Mn, Cu and Ni in the sediment are one order of magnitude higher than those in the common sediment. As shown in the manganese nodules, they may mainly derive from seabed. The contents of all trace metals in the sediment are obviously governed by Fe-and Mn-oxides, organic matter, seawater depth, particle size and Eh. Multi-element correlation equations were developed for all trace metals. The trace metals in acid-soluble fraction of the sediment were also much higher than ihose of common sediment and negatively correlated with water depth, implying the possible influence of carbonate speciation.     

钦州湾桐花树群落沉积物及植物体中重金属元素累积与分异研究

Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals. In this study, the concentration,transport and bioaccumulation of Cr, Cd, Cu, Zn and Pb in the sediments and different parts of Aegiceras corniculatum at four different sites in the Qinzhou Bay in southwestern China were investigated. The results showed that although the potential ecological risk of all five heavy metals was slight, the concentration of Cr was at a moderate pollution level due to the emissions of industries and aquaculture waste water. Core sediment records indicated that the concentrations of heavy metals at the depth of 0–20 cm were relatively high, showing an increasing trend of heavy metals over the past 20–30 years. Cr, Cu, Pb and Cd accumulated mainly in the roots of A. corniculatum, while Zn accumulated mainly in the stems. Aegiceras corniculatum showed the strongest transport capacity for Zn and Cu and the strongest bioaccumulation ability for Cd. Compared with other mangrove communities, A. corniculatum can be chosen as a restoration species in tropical and subtropical coastal zones polluted by Zn, Cu and Cd.     

FORM DISTRIBUTION OF Zn, Cd, Pb AND Cu IN WATERS OF THE NORTHWEST BOHAI GULF

The forms distribution of Zn, Cd, Pb and Cu in waters of the Northwest Bohai Gulf is investigated by inverse polarography of anti-adsorption physically coated mercury film electrode, the higher content of most forms of trace metals is in polluted estuary water, and unstable Zn and Pb are in anomalous distribution. The average concentrations read ΣZn 20.0μg/1 (14.5-36.6 μg/l, ΣCd 0.11pg/1 (0.080-0.14μg/1), ΣPb 1.0μg/1 (0.58-1.6 μg/1), and ΣCu 5.2μg/1) (2.37-8.43 μ/1) respectively.     

ACCUMULATION OFJIHEAVY METALS IN Arca granosa

This paper explores the accumulations ana distributions of Cd, Pb and Cu in clam Area granosa through determining their contents in Dlood and soft parts. The results show an order of concentration factors for these metals therein as: Cd>Cu>Pb; the values of concentration factors and the patterns of distribution are similar for Cu and Pb but different from Cd. Concentration factors in blood can reflect the enrichement abilities of soft parts. Exposure experiments have indicated that the Pb level in blood is controlled by Pb concentrations in surrouding seawater, changing with time, that the Pb cocentration causing poisoning in the seawater is 1-100 μg/1, and that the Pb content in blood and soft parts of Area granosa increases with that of Pb increasing in seawater. There exist relationships of double logatithmic concentrations for Pb among the three mediums.     

A discussion on vertical profiles of dissolved Cu,Cd and Ni in the northwestern Pacific, south of Japan

Some of the results about vertical profile of heavy metals of seawater to the south of Japan in Oct. 1990 are presented and discussed in relation to the concentration of dissolved Cu, Cd and Ni to biogeochemical environments. It points out that the distribution of dissolved Cu is higher in surface water than that in/upper 500 m layer, and maxima value attains the 8. 2 n mol/dm3 in depth of 4 000 m. The concentrations of dissolved Ni ranges from 3. 4 n mol/dm3 in surface seawater to 8. 5 n mol/dm3 in the deep to the south of Japan. The highest values are observed in the colder waters. This paper shows also that the vertical profile of dissolved Cd is perfect nutrient-type distribution. And dissolved Cd and Phosphate are linearly correlated by the regression equation. The ·Cd : ·N : ·P atomic ratio is 3. 5 × 10-4 : 14 : 1.     

黄河口及邻近海域中悬浮体的分布特征和季节性变化

The results of the suspended material measurement in the Huanghe River Estuary show that the silt movement in the estuary is different during summer and winter. The centric water-mass in Bohai Sea enters the Laizhou Bay, which makes the fresh water occupy the head of Laizhou Bay and prevents the silt from spveading to the sea.The disturbing of wind in winter makes the sediment resuspend which results in the high content of suspended materials in the water. The distribution of suspended materials and salinity in summer indicate that because of its own momentum, the silt from the Huanghe River will go ahead out of the river mouth and the effect of centric water-mass in the middle Bohai Sea is relatively small in summer. The distributions of suspended materials in the mid and bottom layer water during different seasons show that the primary direction of the siltl movement in the estuary is towards NE, whice coincides with the movement of residual current.Our paper also presents the size distribution of suspended materials.According to the data, we consider that the silt from Huanghe River moves mainly in the surface layer and the Huanghe River Estuary belongs to weak mixing estuary.     

黄河口沉积物微量元素的多元统计分析

Some microelements totalled ten of sediment samples have been analysed by emission spectrometer. The samples taken from the nearshore area of the Huanghe River and the Lianhe River and the elements analysed are Ni, Co, Cu, Ga, V, Ti, Pb, Zn, Mo, and Mn. Though multivariate analysis by computer, it shows that the effective discriminant elements for the sediments of estuary area of the Huanghe River and Lianhe River are Ti, Zr, Co, V. The Lianhe River Estuary sediments are characterized by higher content of Zr, Co and the Huanghe River Estuary sediments are characterized by higher content of Ti,V. The trend surface analysis shows that the Ni, Ga, Co and Cu have similar tendency of distribution and are closely related with the clayey sediments; Zr and Ti have the similar trend distribution and closely related with coarser grain sediments; the distribution of Mn is in accordance with the area of higher pH. Eh values and is closely related with fine-sandy sediments.     

A study on chemical forms of heavy metals in the sediments of Zhujiang River and its estuary

The five chemical bound forms of Fe, Al and Mn in sediments in the main channel of the Zhujiang River.and its estuary, namely, exchangeable, carbonic, oxidative, organic and residual (in crystal) forms, were determined. The method of sequential extraction was used for separating the five bound forms.The main chemical form of the three elements in the sediments of the Zhujiang River and its estuarine zone is the residual one. The exchangeable form exists only in a small fraction.Correlationships between the concentration of a certain form of heavy metals and Eh. pH and salinity were discussed. The principles of geochemistry are used to explain the mechanism of heavy metal transport in the river.It was also found that the distribution rule of the chemical forms of Fe, Al and Mn in sediments in the lower reaches of the Zhujiang River was similar to the one in the lower reaches of the Yamaska River.     

黄河口附近水文特征分析

The Huanghe River is the second largest river in our country. The average annual runoff at the estuary is 44.28 billion cubic meters, the average annual suspended load is 1.12 billion tons, of which 24% was deposited on the delta, 40% on the coast and the rest 36% is considered to be carried into the deep sea by various dynamic factors. We‘ve measured the temperature, salinity, current and suspended load in the estuary from autumn of 1983 to summer of 1984 for building a harbour in future. According to our data and other historical data from some institutes, we‘ve obtained following conclusions: 1) The distribution of temperature in winter is different with from that in summer: the contours of temperature in winter is parallel to coast line,and the contours of temperature in summer is coincident with latitudes. 2) The salinity in summer is lower than that in winter. There are three tongues of low values of salinity at the estuary in summer. They are pointed to North,North-east and South-east respectively. Only two tongues are appeared in winter-northward and south-eastward. 3) The distribution of suspended load is similar to the distribution of salinity,There are three tongues of high values of suspended load at the estuary in summer, they are pointed to North,North-east and Southeast respectively,the quantity of suspended load per litre in winter is much than in summer. 4) The influence of Huanghe River to North area of the estuary is less than to Laichou Bay. 5) The velocities of tide current at the estuary are very large.The maximum value is about 150era/see, and the directions of tide current are parallel to coastline.     

The source of heavy metals and its indication to the sediment transfer in the Hangzhou Bay

-Suspended matters are important carriers of heavy metals in the hydrocycle.In this paper, the field investigation , lab. experiment and "corresponding analysis" were made to study sources of the heavy metals and the transfer of suspended matters from the Hangzhou Bay.This conclusion shows that the contents of heavy metals in this area are the natural background values ; the distributions of heavy metals are controlled by the plume front.     

GEOCHEMISTRY OF MANGANESE NODULES IN THE NORTHERN CENTRAL PACIFIC

The contents of Mn, Fe, Cu, Co, Ni, Pb and Zn in manganese nodules and associated pelagic sediment from the Northern Central Pacific have been measured, and the correlations between the elements of the nodules and between the chemical composition and the sedimentary environments have been analyzed. It has been found that Cu, Ni and Zn are preferentially enriched in the Mn-oxide phases while Co and Pb in the Fe-oxide phases of the nodules. The elements within the same phase are positively correlated and the elements within different phases are negatively correlated. It is concluded that the elements in the Fe-oxide phase may have directly deposited from seawater while Mn-oxide phase elements are mainly derived from interstitial waters.     

Distribution and sources of heavy metals in the sediment of Xiangshan Bay

Heavy metals in the surface sediments and sediment core from the Xiangshan Bay, a mariculture base on the coast of the East China Sea, were determined by inductively coupled plasma mass spectrometry(ICP–MS) in order to evaluate their levels and sources. The results showed that the levels of Cu, Pb, Zn, and Cr in the sediments of the bay have been generally influenced by anthropogenic inputs since the founding of the People's Republic of China. In particular, Cu and Zn were polluted to some extent, as evidenced by high enrichment factors. Organic matter, grain size, wastewater discharge, and low energy hydrodynamic environment played dominant roles in the heavy metal enrichment in the sediments. The ratio of terrigenous source to marine biogenic deposit of trace metals in the sediments was calculated, revealing that terrigenous inputs were the main source of Cu, Pb, and Zn, while biological pellets contributed much more to the enrichment of Cr and Cd. Considering the influence of biological sources on the enrichment of Cd and Cr, and the fact that the sediment has been polluted by Cu and Zn, the development of mariculture and discharge of wastewater into the Bay should be restricted.     

The chemical distribution characteristics of variant form phosphorus in the seawater of the South China Sea

According to two cruises investigation information in summer and winter during 1998 and1999, the phosphorous concentration distribution and changes of summer and winter were discussed pri-marily in the South China Sea. The results show that the phosphate concentration of surface seawater insummer is distinctly lower than that in winter, averaging 0.04 μmol/dm3 in summer and 0.35 μmol/dm3 in winter. The organic phosphorous concentration of surface seawater in summer is higher than thatin winter, averaging 0.12μmol/dm3 in summer and 0.04 μmol/dm3 in winter respectively. The season-al changes of total phosphorus are similar to phosphate, averaging 0.22 μmol/dm3 in summer and 0.61μmol/dm3 in winter respectively. In vertical direction, phosphate, TDP and TP content are the lowestin upper 50 m water column, and increase in linearity rapidly with water depth, increasing slowly under500 m, reach to maximum about 1 000 m, then decrease slightly with water depth increasing. The ver-tical distribution is typical in summer, and there is small dispersed for phosphorus concentration for thesame depth of different stations. However, in winter there is a large disperse for phosphate, TDP andTP, specifically for phosphate at 200 m at which the concentration is maximum. This result indicatesthat there are large differences in hydrology and biology conditions that affect largely the chemical envi-ronment of the South China Sea. The organic phosphorus is the predominant in surface seawater of theSouth China Sea, but the inorganic phosphorus is the predominant in layers below depth of 150 m. Theorganic phosphorus concentration in deep water usually decreases with water depth increasing. The or-ganic phosphorus in summer is remarkably more than that in winter because of the strong biology activi-ties in summer.