Heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary

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 Zn〉Ni〉Pb〉Co〉〉Cd. 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 fide 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.

A study on suspended matters in the South Huanghai Seain summer time

A joint investigation of marine geoloy in the South Huanshai Sea was carried out by the Institute of Oceanology, Academia Sinica, and the Woods Hole Oceanographic Institution, USA during 1983～1984. This paper reports the investigation results of the suspended matters in the water column at 55 stations in July, 1984 (summer time). The highest concentration region where the value is less than 0.5 mg/L, is found in the central part of the study area and the southern part of Shandong Peninsula. The Taiwan Warm Current which might obstruct the discharge of the Changjiang River to the east of the sea, appears in the distribution of the suspended matters outside the Changjiang River Estuary. Although lots of materials are brought into the sea during the high flow period of the Huanghe and the Chansjiang Rivers in July, this does not form the main scarce of the suspended matters. The main source is the resuspension of depesits. The materials brought by rivers come the second, and biogeneons components in the sea co

Retrieval of Total Suspended Matters Using Field Spectral Data in Shitoukoumen Reservoir,Jilin Province,Northeast China

From August to October in 2006,three times of field spectral measurements with a Field Spec FR spectroradiometer(Analytical Spectral Devices,Inc.,USA) were carried out in Shitoukoumen Reservoir,Jilin Province,Northeast China. Owing to the serious soil and water loss in the upstream,reflectance curves of the reservoir were characterized by high concentrations of total suspended matter(TSM) . Extending the spectral analysis to 1200nm in the near-infrared band,this research revealed an obvious reflectance peak around 1070nm which was caused by the strong backscattering of high TSM. The method of partial least squares(PLS) regression was applied to retrieving the TSM. Reflectance in two spectral bands,i.e.,675-948nm and 1029-1105nm,were used as variables to develop PLS models. Traditional linear regression,first derivative model and logarithmic model were also used for the comparison of different models. Results showed that the PLS model based on Rrs(675) -Rrs(948) gave out best results with high precision and stability. Although the PLS model based on Rrs(1029) -Rrs(1105) did not have an outstanding performance due to lots of noise,the reflectance peak in the near-infrared band was an important TSM feature and its efficient exploitation would have a considerable significance in TSM remote sensing.

Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River

Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.

Distribution and its mechanism of suspended particulate matters in the southern Huanghai Sea and the East China Sea in summer

Water temperature,turbidity,chlorophyll-a and suspended sediment concentration （SSC） were investigated at 61 stations of eight sections in the southern Huanghai Sea （HS） and the East China Sea （ECS） during the summer （28 June to 15 July） of 2006.The horizontal distribution of suspended parti culate matter （SPM） displayed a high concentration inshore and a low value offshore.The maximum value can reach 10.4 mg/dm 3,which can be found at the Changjiang River mouth.For the same site,the SSC was generally higher at the bottom than on the surface.In the vertical direction,distribution characteristics of turbidity can be divided into two types：in the southern HS high values at the bottom while low values on the surface,and in the ECS high values inshore with low values offshore.The thermocline in the HS and the Taiwan Warm Current in the ECS could be important factors preventing the SPM from diffusing upward and seaward.Even the typhoon Ewiniar was not able to work on the major sediment transport under the thermocline during the observation.

Suspended Solids from Drained Peatlands in the East Coastal Zone of New Brunswick： Point Estimates and Climate Effects on the Environment

Peatlands represent one of the most important economic resources and abandoned peatlands after mining can be considered as ecological resources by re-vegetation restoration or management. However, some environmental problems like particles from peatlands and their effects in the water system have to be characterized. Since centuries, artificial drainage has been a current practice for the mining of peatlands. Mainly mined for horticultural purpose, New Brunswick＇s peatlands--predominantly located in the eastern of the province--cover about 140,000 ha. At the downstream end of the drainage system, the water from peatlands flow into sedimentation basins. Drainage waters are often laden with solid particles. Once they have flowed through the ponds to allow sediment settling, the water is released into the water system. This paper describes the spatio-temporal evolution of suspended solids from 12 New Brunswick drained peatlands. The studied sites were characterized by some heterogeneity in the concentration of suspended solids. This study also provides knowledge on the suspended solids amount that can be released by drained peatlands, and it proposes a function to estimate the concentration of suspended solids by using climate variables; and identifies some potential ecological risks.

Numerical Study of Water and Suspended Matter Exchange Between the Yellow Sea and the East China Sea

POM was used to study the monthly mean circulation in the Yellow Sea and East China Sea. The calculated results showed almost all major characteristics of the circulation system. The calculated circulation system and observational data were used to determine the sediment concentration, volume transport, heat flux and suspended matter flux between the Yellow Sea and the East China Sea. The conclusions obtained were that the volume and heat are transported northward through the 32°N section during each season; that in winter and autumn, total suspended matter is transported southward, and is larger in winter than in autumn. The reason is that the Yellow Sea Coastal Current is strong and always contains more suspend matter in winter and autumn. The seasonal suspended matter exchange between the Yellow Sea and the East China Sea are 0.58×10 7 tons in spring, 2.81×10 7 tons in summer, -2.60×10 7 tons in autumn and -3.40×10 7 tons in winter. Net flux of suspended matter from the Yellow Sea to the East China Sea is 2.61×10 7 tons every year.

Estimation of total suspended matter in the Zhujiang (Pearl) River estuary from Hyperion imagery

Although remote sensing data have been used to estimate total suspended matter （TSM） in coastal waters, it has limitations when applied to estuary waters in low spatial resolution situations. The spatial resolution of ocean color satellites such as SeaWiFS and MODIS is usually -1 km, and therefore is not adequate for small, local-scale areas such as the Zhujiang （Pearl） River estuary. In contrast, 30 m-resolution EO-1 Hyperion imagery has potential for studying TSM in localized areas. We measured the surface spectral radiance reflectance of the river estuary water in the visible and near infra-red spectral range. Sensitivity analysis indicated that the ratio of remote sensing reflectance at 813 nm （Rrs（813）） to reflectance at 559 nm （Rrs（559）） could be used to estimate TSM concentration, and a linear relationship was established between the ratio and in-situ TSM concentration. We applied the linear relationship to Hyperion imagery to map TSM concentration in the estuary. The Hyperion imagery provided sufficient spatial resolution to detect spatiotemporal changes in TSM concentrations in the estuary small estuary area. This study demonstrated the usefulness of Hyperion imagery for mapping the distribution of TSM in estuary waters. Keyword： Hyperion; total suspended matter （TSM）; Zhujiang （Pearl） River estuary

The distribution and characteristics of suspended particulate matter in the Chukchi Sea

Samples taken from the Chukchi Sea （CS） during the 4th Chinese National Arctic Research Expedition, 2010, were analyzed to determine the content and composition of suspended particulate matter （SPM） to improve our understanding of the distribution, sources and control factors of the SPM there. The results show that the SPM in the water column is highest in the middle and near the bottom in the south and central-north CS, followed by that off the Alaskan coast and in Barrow Canyon. The SPM content is lowest in the central CS. Scanning electron microscope （SEM） analysis shows that the SPM in the south and central-north CS is composed mainly of diatoms, but the dominant species in those two areas are different. The SPM off the Alaskan coast and in Barrow Canyon is composed mainly of terrigenous material with few bio-skeletal clasts. The distribution of temperature and salinity and the correlation between diatom species in SPM indicate that the diatom dominant SPM in the south CS is from the Pacific Ocean via the Bering Strait in summer. The diatom dominant SPM in the central-north CS is also from Pacific water, which reaches the CS in winter. The SPM in the middle and near the bottom of the water column off the Alaskan coast and in Barrow Canyon is from Alaskan coastal water and terrigenous material transported by rivers in Alaska.

The increased storage of suspended particulate matter in the upper water of the tropical Western Pacific during the 2015/2016 super El Nino event

The climate variability induced by the El Nino-Southern Oscillation(ENSO)cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Nino event occurred in the equatorial Pacific.Suspended particulate matter(SPM)data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Nino event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Nino events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Nino event on the global carbon cycle and has profound implications for understanding El Nino events.

Seasonal Suspended Particles Distribution Patterns in Western South Yellow Sea Based on Acoustic Doppler Current Profiler Observation

An Acoustic Doppler Current Profiler （ADCP） observation site was set up in the Western South Yellow Sea from 2012 to 2013 to study the local suspended particle matters （SPM） distribution pattern. The SPM concentration could be semi-quantitatively represented by backscatter intensity （Sv）, converted by the echo intensity （E/） of ADCP. Results show two types of SPM in the water column： the quasi-biological SPM and quasi-mineral SPM. The quasi-biological SPM mainly exists in summer half year and is con- centrated above the thermocline. It has periodically diurnal variations with high concentration at night and low concentration in the daytime. The quasi-mineral SPM is located in lower part of the water column, with similar relation to monthly tidal current variation all year round. However, the daily quasi-mineral SPM distribution patterns vary between summer and winter half year. The sunlight is thought to be the origin factor leading to the diurnally vertical motion of the biological features, which might cause the diurnal Sv variation. Unlike in winter half year when tidal current is relatively single driving force of the monthly SPM pattern, the high speed current near the thermocline is also responsible for the concentration of quasi-mineral SPM in summer half year. The sediment input difference between summer and winter half year contribute to the varied daily variation of quasi-mineral SPM with re-suspended SPM ir~ winter and sediments from Yellow Sea Mud Area （YSMA） in summer. The seasonal variations in hydrodynamics, water structure and heavy-wind incidents are the primary factors influencing the differential seasonal SPM distribution patterns.

Correlation Study Between Suspended Particulate Matter and DOAS Data

Continuous data of aerosol optical thickness monitored using differential optical absorption spectroscopy （DOAS） are correlated with the concentration of ground-measured suspended particulate matter （SPM）. A high correlation is found between the DOAS and the ground SPM data, making it possible to calculate the mass extinction efficiency of the aerosols in the atmosphere. It is found that the value of mean mass extinction efficiency （MEE） varies over a range of 2.6-13.7 m^2 g^-1, with smaller and larger values occurring for size distributions dominated by coarse and fine particles, respectively.

Spatial Variation and Risk Assessment of Arsenic and Heavy Metals in Surface Water and Suspended Particulate Matter in Tail Reaches of the Yellow River, China

To determine the pollution levels and potential toxic risks of arsenic(As) and heavy metals(Cr, Ni, Cu, Zn, Pb and Cd) in water and suspended particulate matter(SPM) in tail reaches(including freshwater reach and low-salinity reach) of the Yellow River as the Flow-Sediment Regulation Project(FSRP) has been carried out for approximately 15 yr, the surface water and SPM were sampled at pre-flood(April) and post-flood seasons(October). Results showed that similar changes of As and metal levels in water and SPM were observed along the tail reaches at pre-flood or post-flood season. Compared to pre-flood season, the levels of As, Cu, Cr and Ni in freshwater reach and the concentrations of Cr and Ni in low-salinity reach rose greatly at post-flood season. The levels of As and metals in SPM of freshwater reach or low-salinity reach at pre-flood season were significantly higher than those at post-flood season(P < 0.01).The pollutions of As and metals in surface water of tail reaches at pre-flood or post-flood season were not serious. The SPM in freshwater reach at pre-flood season were polluted by Cd, As, Cr, Cu and Ni while those in low-salinity reach were polluted by Cd and Cr. The SPM in freshwater reach at post-flood season were polluted by Cd and Pb while those in low-salinity reach were polluted by Cd and Cr.Cd was identified as heavy metal of primary concern at both pre-flood and post-flood seasons. Combined with the existed data reported in present research, this study found that the toxic risk of As and metals in SPM of tail reaches at pre-flood season was higher than that at post-flood season, implying that the implementation of FSRP during flooding season, to a great extent, reduced the toxic risk of these elements. With the long-term implementation of FSRP, the pollution levels of As and metals(particularly for Cd) in SPM of tail reaches might be elevated and the potential toxic risk primarily produced by Cr, Ni and As might be increased if effective measures were not taken in future.

The grain-size distribution of the suspended particulate matter in the Huanghe Estuary and its adjacent sea area in winter

The grain-size of suspended particulate matter （SPM） in the Huanghe Estuary and its adjacent sea area was investigated with an in situ laser particle size analyzer （LISST-100） in November 2006.The spatial distribution of the grain-size parameters was very complicated.The results show that （1） the mean particle size of SPM ranged from 3.00Φ to 6.41Φ,with an average value of 4.66Φ;（2） the frequency distribution patterns of the SPM grain-size showed three different types,which were mono-mode,dual-mode and tri-mode,respectively;（3） C-M chart suggested that the transportation-processes of the SPM not only included suspended mode,but also the bed load transportation mode.The bed load transportation mode mainly occurred at the bottom layer.The characteristics and space distribution of SPM grain-size might be mainly controlled by sediment discharge of the Huanghe River,hydrodynamics condition,surface sediment types,and biological process within the study area.

VARIATIONS OF THE SUSPENDED MATTERAMD THE PARTICULATE ORGANIC CARBONIN THE ENTRY OF THE GIRONDE ESTUARY, FRANCE

The effects of using different types of glass fiber filters (GF/F, GF/C) and of sample treatments were evaluated. Studies on the variation of suspended matter (SM) and particulate organic carbon (POC) showed that:1) the transversal and day to night variations are important and must be taken into account in order to get a correct river flux; 2) no regular seasonal variations of SM and POC were observed, as they are controlled essentially by the climatological, hydrologic, physiochernical, biological, and geological conditions of the drainage area.

Observations on carbon and nitrogen content of suspended matter in a headwater stream in Hong Kong

The total carbon(C) and total nitrogen(N) content of suspended matter in a small undisturbed headwater drainage basin in the New Territories of Hong Kong has been monitored. Mean C and N contents were 12.85% and 0.99% respectively for 132 samples. Samples collected under stableflow conditions had mean C and N contents of 12.81% and 1.06% respectively. Stormflow samples had mean C and N values of 12.86% and 0.97% respectively, which were very similar to the levels observed under stableflow conditions. The mean C∶N ratios of 12.47 and 13.39 for stableflow and stormflow also reveal little difference according to hydrologic conditions. When all the data is considered little difference is observed in C and N according to the season. However, in winter there is a significant difference in C and N content between stable and stormflow samples. When C and N are plotted against water level the scattergraphs suggested that as stage increases the percentage of C and N in the suspended matter declines. Scattergraphs of C and N against suspended sediment concentration reveal a negative association. Comparison has been made between fresh leaf C, N and C/N ratio for trees and shrubs and the suspended matter. Fresh leaves do not appear to contribute significantly to suspended matter. The C/N ratio of suspended matter would also seem to exclude woody material and algae as sources of suspended matter.

Characteristics and Origins of Suspended Pyrite in the Mixing Zone of the Yangtze Estuary

For a long time,most studies about pyrite have focused on sediments while only a few have focused on pyrite in water.In this study,a method that combines the scanning electron microscopy(SEM)and the energy dispersive X-ray spectrometry(EDS)was used to compare pyrite particles suspended in water to those in associated bottom sediments,both obtained from the mixing zone of the Yangtze Estuary.It was found that the pyrite particles in the two media have similar morphologies and size distributions.The particle morphology mainly includes two types,single crystal and aggregate,and the particle size mainly ranges from 0.5 to 2μm.The pyrite particles in water exhibit an increase in relative content towards the sea,and their transport and deposit processes are mainly affected by hydrodynamic conditions.It is concluded that the pyrite particles in the suspended matter mainly derived from the resuspension of sediments,which are products of the early diagenesis.Precursor minerals may appear during the formation of pyrite,but are generally restricted by the diagenetic environment and local microenvironment.

Evaluation of the retrieval of total suspended matter concentration in Taihu Lake,China from CBERS-02B CCD

Remote sensing techniques is used to quantify the total suspended matter concentration （CTSM）. In this study, we used remotely sensed data to retrieve the CTSM for the Taihu Lake, China, and developed an atmospheric correction algorithm especially for CBERS-02B CCD data. We simulated the remote sensing reflectance （Rr~） of CCD bands using in-situ observations made in a cruise over the Taihu Lake in autumn 2004, from which a retrieval model is established with simulated Rrs（830） and measured CTSM. In addition, we applied the atmospheric correction algorithm and retrieval model to process the CCD data over the lake in 2008 and to retrieve the CTSM. The RMS relative error between the CTSM retrieved from MODIS and from the CCD images is about 42.9%, indicating that algorithms described in this paper can be used for the application of CCD data in monitoring the CTSM distribution in the Taihu Lake.

A Study of Suspended Particulate Matter in Lahore (Pakistan)

The results obtained from an investigation of suspended particulate matter in the metropolitan city of Lahore (Pakistan) are reported and analysed in this paper. X-ray diffraction studies of the airborne matter collected from various urban and suburban sites show that non-clay minerals such as quartz, calcite and albite are contained in most of the samples in almost comparable amounts. Chemical analysis of some samples was carried out for complementing the x-ray diffraction data. The amount of quartz in the samples of dusty areas was found to be an order of magnitude more than in the samples of relatively cleaner areas. As the dust particles of these compounds are poor substrate for promoting nucleation of ice in the atmospheric clouds, they are liable to stay steadily in the atmosphere as pollutants.A comparison of the results of the airborne particulates and the soil samples collected from various sites show that the sources of quartz, calcite and albite in the airborne matter are both local and remote.

Fronts and transport of suspended matter in the Hangzhou Bay

A persistent, year-round NE-SW front is found to exist inside the Hangzhou Bay. This front is actually the merging of the secondary Changjiang plume front from the bay mouth and the Qiantang plume front from the upstream side of the bay. During neap tides low runoff periods these two plumes can readily be identified. Our findings suggest that suspended matter is transported into the bay through the north end by the secondary Changjiang plume. The front inside the bay acts the part of concentrating suspended matter, and also plays an important role in both the fine-grained sediment and heavy metal distributions in this sedimentary basin.