Spatial distribution of dissolved Pb, Hg, Cd, Cu and As in the Bohai Sea

Characteristics of the spatial distribution of selected dissolved heavy metals were analyzed during large scale surveys from August 12 to 25,2003 in the Bohai Sea.Dissolved Pb was the only element with average concentrations higher than the grade-one sea water quality standard of China.The spatial distribution of dissolved Pb in surface water was similar to those of Cd,Cu and As,where the isopleths generally indicated decreasing values from the bays to the central areas.Only for Hg did the high concentrations not only appear in Liaodong Bay,Bohai Bay and Laizhou Bay,but also in the Central Area,viz.not only in inshore but also in offshore areas. Vertical distributions of dissolved Pb,Cd,Cu and As were largely uniform,while that of dissolved Hg increased with depth.We infer that the input of pollutants from land was the main influencing factor for the detected distribution patterns of dissolved heavy metals, followed by the dynamics of sea water,release from bottom sediments and biochemical processes.Comparing with historical data, average concentrations of dissolved heavy metals appear to decline in recent years.     

Distribution and contamination status of chromium in surface sediments of northern Kaohsiung Harbor, Taiwan

The distribution, enrichment, accumulation, and potential ecological risk of chromium (Cr) in the surface sediments of northern Kaohsiung Harbor, Taiwan, China were investigated. Sediment samples from ten locations located between the river mouths and harbor entrance of northern Kaohsiung Harbor were collected quarterly in 2011 and characterized for Cr, aluminum, water content, organic matter, total nitrogen, total phosphorous, total grease, and grain size. Results showed that the Cr concentrations varied from 27.0 to 361.9 mg/kg with an average of (113.5±87.0) mg/kg. High Cr concentration was observed near the Jen-Gen River mouth. The mean Cr concentration was high at 255.5 mg/kg, which was at least 2 to 7 times than that of other sites. This might imply significant Cr contribution from upstream receiving tanneries wastewater into the Jen-Gen River. The spatial distribution of Cr reveals relatively high in the river mouth region, especially in Jen-Gen River, and gradually diminishes toward the harbor entrance region. This indicates that the major sources of Cr pollution from upstream industrial and municipal wastewaters discharged along the river bank; and Cr may drift with sea current and be dispersed into open sea. Moreover, Cr concentrations correlated closely to the physical-chemical properties of the sediments, which suggested the influence of industrial and municipal wastewaters discharged from the neighboring industrial parks and river basins. Results from the enrichment factor and geo-accumulation index analyses imply that the Jen-Gen River sediments can be characterized as moderate enrichment and none to medium accumulation of Cr, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information to developing future strategies for the management of river mouth and harbor.     

Significance of dredging on sediment denitrification in Meiliang Bay, China： A year long simulation study

An experiment for studying the effects of sediment dredging on denitrification in sediments was carried out through a one-year incubation of undredged (control) and dredged cores in laboratory. Dredging the upper 30 cm of sediment can significantly affect physico-chemical characteristics of sediments. Less degradation of organic matter in the dredged sediments was found during the experiment. Denitrification rates in the sediments were estimated by the acetylene blockage technique, and ranged from 21.6 to 102.7 nmol N2/(g dry weight (dw)·hr) for the undredged sediment and from 6.9 to 26.9 nmol N2/(g dw·hr) for dredged sediments. The denitrification rates in the undredged sediments were markedly higher (p0.05) than those in the dredged sediments throughout the incubation, with the exception of February 2006. The importance of various environmental factors on denitrification was assessed, which indicated that denitrification was regulated by temperature. Nitrate was probably the key factor limiting denitrification in both undredged and dredged sediments. Organic carbon played some role in determining the denitrification rates in the dredged sediments, but not in the undredged sediments. Sediment dredging influenced the mineralization of organic matter and denitrification in the sediment; and therefore changed the pattern of inherent cycling of nitrogen.     

Assessing high resolution oxidation-reduction potential and soluble reactive phosphorus variation across vertical sediments and water layers in Xinghu Lake: A novel laboratory approach

To understand the transfer process of soluble reactive phosphorus (SRP) on the lake sediment-water interface in a mesotrophic shallow lake in South China, the SRP concentrations and the oxidation-reduction potential (ORP) across the sediment-water interfaces were continually monitored. Sediment samples were collected from Xinghu Lake in Guangdong Province. The ORP dynamics at di erent layers of overlying water was similar for six experimental systems, whereas those in porewater were significantly di erent. The ORP in overlying water was 200–300 mV higher than those in sediments. The oxygen penetration depth ranged from 2 to 10 mm in Xiannu Lake sediments. The variation amplitudes of ORP increased with sediment depth, but the mean ORP values were all about 218 mV. The SRP concentrations in porewater maintained at a low level of about 0.049 mg/L because of high atom ratio of total iron and total manganese to total phosphorus. The SRP concentrations and variation amplitudes in porewater increased with sediment depth. The SRP in overlying water mainly originated from SRP transference of the porewater of middle and bottom sediments (3–15 cm). The ORP variation and SRP transfer in porewater played important roles in changing SRP concentrations. A distinct SRP concentration gradient appeared in overlying water when intense exchange occurred at the sediment-water interface; therefore, it was necessary to monitor the SRP concentration profiles to accurately estimate the internal loading.     

Heavy metals in surface sediments from Minjiang Esturary—Mazu and Xiamen—Jinmen sea areas

The concentrations of Cu,Pb, Zn and Cd in surface sediments from Minjang Estuary-Mazu and Ziamen-Jinmen sea areas of China were investigated during 1995-1996.The concentration ranges of Cu,Pb ,Zn and Cd in the Minjiang Estuary-Mazu sea area were 16.4-37.2,33.4-69.6,92.1-128,0.087-0.036mg/kg(dry wt.),respectively; those for Xiamen-Jinmen sea area were 11.0-24.5,36.0-80.3,77.5-161,0.135-0.285mg/kg(dry wt.), respectively.The concentration and distributions of Cu,Pb,Zn and Cd in surface sediments of Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas were analyzed and evaluated.The results showed that the values of Zn and Pb exceeded those of sediment quality criteria.The average concentration of Cu in Minjiang Estuary-Mazu sea area was higher than that in Xiamen-Jinmen sea area.The obviously higher concentrations of Cu,Pb, Zn and Cd were found at outlets of Minjiang and Jiulong River.From the estuaries to open sea, the concentrations of Cu, Pb,Zn and Cd had a decreasing trend, and then elevated in the sea areas near Mazu and Jinmen, suggesting that Cu,Pb,Zn and Cd in Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas may come from both the mainland and Taiwan of China.     

Characteristics and distribution of low molecular weight organic acids in the sediment porewaters in Bosten Lake, China

The composition and vertical profiles of low molecular-weight organic acids (LMWOAs) and the contribution of them to dissolved organic matter (DOM) in sediment porewaters in Bosten Lake, Xinjiang, China were investigated. The results showed that total concentration of LMWOAs was up to 94.5 μmol/L and their proportion in DOM was 5.6%, suggesting that LMWOAs were important chemical components in DOM in lake sediment porewaters. Among the seven LMWOAs, pyruvic and acetic acid had the highest concentrations with 26.30 and 8.31 μmol/L, accounting for 51.4% and 14.92% of LMWOAs, respectively. Trifluoroacetic and sorbic acid had the lowest concentrations, indicating that the compositions of LMWOAs in relative reducing environments were largely different from those reported in glacier, atmosphere and soils. The concentrations of lactic, acetic, formic, sorbic and oxalic acid decreased with increasing depth, probably relating to stronger microbial activities in the initial stage of early diagenesis. Trifluoroacetic acid was mainly anthropogenic with its concentration, showing a diusive trend from the surface to bottom sediments. The concentrations of lactic acid and nitrate generally showed a consistent profile. The increasing concentration of pyruvic acid in the vertical profile was just opposite to that of sulfate, revealing a significant negative relationship between them. Oxalic acid remained constant except for an obvious peak at 6 cm depth. The results indicated the diversities in sources and behaviors for various LMWOAs during early diagenesis in sediments.     

Microbial bioavailability of dissolved organic nitrogen (DON) in the sediments of Lake Shankou, Northeastern China

Dissolved organic nitrogen(DON)extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions.The bioavailabilities of the hydrophobic and hydrophilic fractions to three types of bacterial communities collected from sediments,activated sludge and compost products were examined.The DON recoveries obtained by DAX-8 and cation exchange resins treatment were 96.17% ± 1.58% and 98.14% ±0% for the samples obtained from N4 and N14 stations,respectively.After 25 days of incubation at 25°C,most DON(59% to 96%)was degraded.Hydrophilic DON exhibited a higher reduction rate than hydrophobic DON during the growth phase.Untreated wastewater from Changshuihe town was the main degradable DON source to station N4,and 93% of hydrophilic DON and 80% of hydrophobic DON were degraded.Station N14 received a large amount of refractory DON from forest soils and exhibited DON degradation rates of 82% and 71% for the hydrophilic and hydrophobic fractions,respectively.Amino acid contents and fluorescence intensities were also analyzed.Approximately 27% to 74% of amino acids were taken up by day 5,and their concentration gradually increased in the following days due to the decomposition of dissolved proteins.Parallel factor analysis resulted in identification of tryptophan-like proteins,tyrosine-like proteins and FA-like substances.During the growth phase,40%–51% of the tryptophan-like proteins were taken up by bacteria,and the accumulation of tyrosine-like proteins was attributed to the release of biotic substances.The concentration of the FA-like substances decreased due to microbial decomposition.     

Identification of a marine woloszynskioid dinoflagellate Biecheleriopsis adriatica and germination of its cysts from southern Chinese coasts

A strain of small-sized dinoflagellates, isolated from the culture of sediment incubation collected from the coastal areas in southern China, has been identified under microscopical observation and r DNA sequence. Surface sediments from two sea areas in the southern Chinese coastal waters were incubated for 20 and 40 days, and germinated vegetative cells were observed. The cells were identified as species in the Suessiaceae based on the morphological characteristics, ultrastructural features of the cell, as well as its swimming behavior. The studied strain clusters into a well-supported clade together with six sequences of Biecheleriopsis adriatica in the phylogenetic tree based on the large subunit(LSU) rDNA sequence. Therefore, the strain has been identified as B. adriatica based on morphological observation and phylogenetic analysis. B. adriatica was the dominant dinoflagellate species in the germinated phytoplankton community from both sea areas,which contributed 50%–83% to the total germinated dinoflagellates averagely. However,B. adriatica has not been reported in previous phytoplankton surveys, and was probably ignored or misidentified due to its small size and thin wall. The frequent and abundant occurrence of B. adriatica in the germinated phytoplankton community of many sea areas of the southern Chinese coastal waters suggests its wide and abundant distribution in these sea areas.     

Spatial and temporal variability of marine-origin matter along a transect from Zhongshan Station to Dome A, Eastern Antarctica

The spatiotemporal distribution pattern of marine-origin matter on the Antarctica ice sheet was used to study variations in the source regions, transport mechanisms and postdepositional influences. We present data on sea salt ions, sulfur components and stable isotopes from surface and snow pit samples collected along the transect route from Zhongshan Station to Dome A during the austral summer in 2012–2013. A general decreasing trend in the accumulation, sea salt ions and sulfur components occurred with increasing distance from the coast and increasing elevation. However, different sources of the marine components, transport pathways and post-depositional influences were responsible for their different spatial distribution patterns. The marine ions in the coastal snow pit varied seasonally, with higher sea salt ion concentrations in the winter and lower concentrations in the summer; the opposite pattern was found for the sulfur compounds. The sea ice area surrounding Antarctica was the main source region for the deposited sea salt and the open sea water for the sulfur compounds. No significant trends in the marine-origin components were detected during the past 3 decades. Several periods of elevated deposition of sea salt ions were associated with lower temperatures(based on δD and δ18O) or intensified wind fields. In comparison to the sea salt ions, the sulfur concentrations exhibited the opposite distribution patterns and were associated with changes in the surrounding sea ice extent.     

Study of heavy metal speciation in branch sediments of Poyang Lake

This study concentrates on the environmental pollution level of sediments in the six branches of Poyang Lake, the biggest fresh water lake in China. This is the first systematic report on the speciation analysis of heavy metals （Cu, Co, Cd, Pb, and Ni） in the six branches of the lake. A reported analytical procedure involving a five-step sequential extraction is used for the partition of particulating heavy metals. The sediment samples are analyzed using flame atomic absorption spectroscopy （FAAS）. Experimental results obtained from five replicate samples of fluvial bottom surface sediments at the sampling points demonstrated that the relative standard deviation of the sequential extraction procedure was generally better than 10% （Cd except）. The average extracted contents of the five elements, analyzed after all five steps, are found to be （mg/kg） for Cu： 26.89, Co： 16.25, Cd： 1.08, Pb： 37.98, and Ni： 20.46. The content of the exchangeable species was generally lower. Except Cu, the percentage of the species bond to organic matter was lower than 20%. The fractions containing the most metal for Cu, Co, and Ni were the residues （52.26%, 45.28%, and 74.82%, respectively）.     

Water purification with sintered porous materials fabricated at 400℃ from sea bottom sediments

A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sediments dredged from Ago Bay into value-added recycled products. The sintered products fabricated at 400℃ were found to be very effective adsorbents for the removal of heavy metals.     

黄渤海典型海域DGM变化及其影响因素

采集黄渤海海域海水,研究近海、远海、河口海域溶解气态Hg（DGM）变化及其差异。结果表明,近海表、底层海水DGM浓度较高（分别为160~230 pg/L,160~250 pg/L）,中层最低（50~140 pg/L）,近海沉积物再悬浮导致沉积物中产生的DGM释放到上层海水,所以底层高于中层。远海站点表层、中层海水DGM浓度高（分别为140~210 pg/L,130~200 pg/L）,底层最低（60~180 pg/L）。表层海水DGM主要是光还原产生,而底层海水的DGM来自上层DGM的扩散或沉积物的释放。长江、黄河河口附近海域表层海水DGM浓度高,随着深度的增加,DGM浓度减小,底层沉积物产生的DGM较少,长江口附近的低氧区未发现DGM的高浓度值,说明低氧区不能导致DGM的大量产生。     

厂坝铅锌矿床中钠长石岩的成因探讨

厂坝铅锌矿床中钠长石岩的产状、常量元素、微量元素、稀土元素和放射性同位素等地质地球化学特征表明．该岩石为中泥盆统成矿流体在海底沉积和交代围岩形成的典型热液沉积岩——钠长石岩，其物质来自矿体的下状沉积地层柱和海水。该沉积岩在后期的强烈变质改造过程中，发生了重结晶作用。     

放射性核素在海水、底质及海洋生物间的转移--Ⅰ.核素进入海水后的初始状态

作者在建立的人工小生境中,研究了具有生态学意义的~(137)Cs、~(134)Cs、~(65)Zn、~(60)Co、~(59)Fe、~(54)Mn等核素在海水、底质及海洋生物间的转移规律.本文是该项研究的第一部分,研究悬浮物、底质对核素的富集和吸附,考察了核素进入海水后的初始状态.     

Pollution in the Baltic Sea

3  , NO_x, PO₄) caused eutrophication and consequent oxygen depletion in coastal bottom waters as well as in the depths of the open sea. In the anoxic sediments, hydrogen sulfide can be produced by protein-decomposing and sulfate-reducing bacteria. The bottom fauna will be destroyed and only H₂S tolerant microorganisms can survive. Originating from cellulose manufacturing and from paper mills, large amounts of poisonous chlorinated compounds contaminated the coastal waters of Sweden and Finland until the 1980s. Most of this material is still present in sediments of the central Baltic Sea and can be resuspended by near bottom currents. To reduce pollution and improve the situation in the Baltic Sea, the surrounding countries organized the Helsinki Convention, which came into force on 3.5.1980. The Helsinki Commission (HELCOM) founded in 1974 acts as coordinator and is responsible for the enforcement of the Baltic monitoring program and international research projects. The activities of HELCOM have led to the reduction of dangerous pollutants which in turn has caused the regeneration of flora and fauna in some areas. Further improvements can be expected.     

胶州湾湿地沉积物中HCHs和DDTs含量水平与评价

2009年,以胶州湾湿地为研究区域,分别于2,5,8,11月进行表层沉积物采集,并对沉积物中HCHs和DDTs含量进行检测。结果表明:潮间带区域表层沉积物中HCHs含量范围:(17.56～77.39)×10-9,DDTs含量范围:(ND～89.87)×10-9;浅海区域表层沉积物中HCHs含量范围:(ND～62.71)×10-9,DDTs含量范围:(ND～73.43)×10-9。各测站沉积物HCHs、DDTs含量变化与胶州湾入湾河流的流量变化相一致。即:丰水期含量偏高,枯水期含量偏低,说明二者主要来源于河流输入和地表径流输入。     

天津汉沽海域表层沉积物中P的赋存特征分析

利用连续分级提取方法,对天津汉沽海域表层沉积物中P的含量水平、赋存形态、及其生物有效性进行了分析。结果表明:表层沉积物中TP的含量在525.68×10-6～688.39×10-6之间,平均含量约为618.18×10-6,其中86.98%以IP的形式存在;而在IP中,FA-P是其主要的赋存形态,平均约占TP的59.54%;IP含量范围为48.52×10-6～146.72×10-6,平均约占TP的13.02%。P的生物有效性分析结果显示,潜在的生物有效P主要包括Ads-P、Fe-P和OP等3种赋存形态,而天津汉沽海域表层沉积物中潜在的生物有效P含量约为465.87×10-6～609.79×10-6,平均约占沉积物TP的89.14%,表明研究区域内沉积物具有很强的释P潜力。     

陆丰核电周边海域表层沉积物放射性核素比活度水平研究初探

本文采用γ能谱法对陆丰核电周边海域表层沉积物中的放射性核素进行分析测定。研究表明, 陆丰核电周边海域表层沉积物样品中的铀系核素衰变不平衡:210Pb相对于226Ra过剩;226Ra相对于238U缺损。钍系核素228Th和228Ra则接近衰变平衡。与我国部分海域沉积物放射性含量相比,陆丰核电周边海域表层沉积物样品中核素238U、228Th的放射性比活度值位于中等水平,其余核素（40K、226Ra、210Pb、228Ra 、 137Cs）的比活度值均接近于南海东北部表层沉积物核素比活度值。总体而言,研究海域表层沉积物样品放射性水平与历史数据无明显差异,处于本底范围。     

京杭大运河(徐州段)砷的形态的分步特征研究

文章对京杭大运河(徐州段)底泥中的11个样品进行研究,对底泥中的砷的总量和形态进行测定,结果表明砷的污染已经达到中度污染并且砷的形态大部分是以钙型和包裹态形式存在。分别采用总有机碳测定仪和X-衍射(XRD)测定11样品中有机碳(TOC)的含量和底泥的成分,结果表明底泥的成分主要有石英、石膏,部分或少量的长石、方解石和粘土矿物,底泥中的有机碳的含量不能决定砷的总量和形态的分布。