戴民汉
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- 姓名:戴民汉
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学术头衔:
博士生导师, 国家杰出青年科学基金获得者
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学科领域:
海洋化学
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暂无
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4389
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1054
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成果数
15
戴民汉, Z. Zhang, a, M. Dai, b, H. Hong, J. L. Zhou *, c, and G. Yu a
J. Environ. Monit., 2002, 4, 922-928,-0001,():
-1年11月30日
Persistent organic pollutants (POPs) such as organochlorine (OCl) insecticides and polychlorinated biphenyls (PCB), together with the new generation of organophosphorus (OP) insecticides, are of global concern, due to their widespread occurrence, persistence, bioaccumulation and hormone disruption potential. This paper represents an attempt to study the source and transportation of such pollutants in estuarine and coastal environments as an integrated ecosystem, by determining the levels of 18 OCl insecticides, 21 PCB congeners, and 17 OP insecticides in the Pearl River Estuary and South China Sea. The total concentrations varied from 126-1198 ng l21 for OCl insecticides, 33.38-1064 ng l21 for PCB congeners, and 4.44-6356 ng l21 for OP insecticides in the Pearl River Estuary. In comparison, their levels in the South China Sea were significantly lower, varying from 57.09-202 ng l21 for OCl insecticides, 21.72-144 ng l21 for PCBs, and 1.27-122ng l21 for OP insecticides, respectively. The predominance of b-HCH in HCHs, and DDE in DDTs in all water samples was clearly observed, suggesting b-HCH and DDE's resistance to further degradation. The PCBs were dominated by those with 3-6 chlorines. The distribution characteristic of OP insecticides shows that five compounds (methamidophos, dimethoate, malathion, dichlorvos and omethoate) accounted for 56% and 72% of the total OP insecticide concentration. The relationship between pollutant concentrations and salinity in the estuary showed that they were all removed during the mixing process, therefore behaving non-conservatively.
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【期刊论文】Sources and Migration of Plutonium in Groundwater at the Savannah River Site
戴民汉, MIN HAN DAI, †, ‡, JAMES M. KELLEY, §, AND KEN O. BUESSELER *
Environ. Sci. Technol. 2002, 36,3690-3699,-0001,():
-1年11月30日
The isotopic composition, size distribution, and redox speciation of plutonium (Pu) in the roundwater in the vicinity of the F-area seepage basins at the U.S. Department of Energy Savannah River Site (SRS) were examined. A low 240Pu/239Pu ratio in the upstream control well signifies a Pu source other than global fallout and indicates reactorproduced Pu. Elevated 240Pu/239Pu atom ratios downstream from the seepage basins are due to the decay of transplutonium isotopes, mainly 244Cm to 240Pu, which were generated at the SRS. Evidence suggests that the migration of basin-released Pu isotopes is minor. Rather, it is the transplutonium isotopes that migrate preferentially downstream and in the process decay to yield progeny Pu isotopes. Size fractionation studies with crossflow ultrafiltration show that <4% of the 239Pu or 240Pu is found in the colloidal fraction, a finding that is consistent with the higher Pu oxidation states observed in the SRS groundwater. The observation of a low abundance of colloidassociated Pu in SRS groundwater cannot be extrapolated to all sites, but is in contrast to the conclusions of prior groundwater Pu studies at the SRS and elsewhere. This work is unique in its application of a novel combination of sampling and processing protocols as well as its use of thermal ionization mass spectrometry for the detection of Pu isotopes. This allows uantification of the Pu source terms and better determination of the ambient Pu size and redox speciation representative of in situ conditions.
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戴民汉, Ken O. Buesseler * and Martin Hassellov, Minhan Dai
ENVIRONMENTAL SCIENCE & TECHNOLOGY/VOL. 37, NO.3, 2003,-0001,():
-1年11月30日
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【期刊论文】Distribution of dissolved organic matter in the Pearl River Estuary, China
戴民汉, Julie Callahana, Minhan Daib, *, RobertF. Chena, Xiaolin Lib, Zhongming Lub, Wei Huangb
Marine Chemistry 89(2004)211-224,-0001,():
-1年11月30日
Chromophoric dissolved organic matter (CDOM) fluorescence and dissolved organic carbon (DOC) were measured in the Lingdingyang Estuary, a major component of the Pearl River Delta, China, in May 2001 and November 2002. Measurements of CDOM and DOC suggest multiple sources of dissolved organic matter (DOM) in the low-salinity region of the estuary, due to the mixing of four freshwater outlets, Humen, Jiaomen, Honqimen and Hengmen, all with different freshwater endmembers and all flowing into the head of the Lingdingyang. Our 2002 cruise expanded efforts to characterize these four major outlets, allowing for the quantification of CDOM inputs within this complex watershed. DOC and CDOM appear conservative in mid-salinity (5-20) waters, suggesting that mixing dominates production and removal processes over time scales on the order of 3 days, the residence time of water in this region of the estuary. DOC and fluorescence are linearly correlated in the mid-salinity region of the estuary north of Shenzhen, suggesting that in this region, terrestrial inputs dominate both signals. However, this relationship does not continue out onto the shelf, where water masses of differing optical properties mix. The CDOM/DOC ratio decreases with increasing salinity as would be expected through phototrasformation of CDOM into non-fluorescent DOC. Additionally, this ratio at low salinity appears to vary seasonally, with a higher value in Spring (high flow) compared to Fall (low flow).
CDOM, Pearl River Estuary, Fluorescence, Dissolved organic carbon
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戴民汉, Wei-Jun Caia, *, Minhan Daib, Yongchen Wanga, Weidong Zhaib, Tao Huangb, Shuitu Chenc, Fan Zhangc, Zhaozhang Chenb, Zhaohui Wanga
Continental Shelf Research 24(2004)1301-1319,-0001,():
-1年11月30日
The Zhu-jiang (Pearl River) estuary and its adjacent continental shelf in the Northern South China Sea (SCS) is unique in that its drainage basin is located entirely in a subtropical zone with heavy population development, and therefore represents an important regime for biogeochemical studies on how large rivers influence continental shelves. The near-zero salinity end member has high nutrient concentrations (silicate 130-140μM, nitrate 75-100μM and phosphate 0.2-1.2μM) and relatively high total dissolved inorganic carbon (DIC) (1500μM) and alkalinity (B1650μM) values. Water column DIC, alkalinity, and nutrient in the estuary are largely controlled by mixing of waters from different tributaries with different drainage basin chemistry, anthropogenic influence, and degree of estuarine recycling. Biological uptake of nutrients and inorganic carbon occur in the outer estuary and inner shelf areas supported by riverine nutrients. The N/Pand Si/P ratios are generally very high within the estuary. The summertime area-integrated biological production rate of 0.8 gCm-2 d-1 is estimated based on the depletion of DIC and alkalinity relative to the conservative mixing line and a plume travel time. This estimate agrees reasonably well with 14C based primary production rates (PP) and with that from effective river phosphate flux. Biological production decreases about 10-fold in the open continental shelf and slope and is largely supported by mixing with subsurface water. A comparison of DIC, phosphate, and nitrate concentrations in the surface mixing layer and at the bottom of the euphotic zone with the 14C-based PP (0.13 gCm-2 d-1) suggests that the surface water residence time in the Northern SCS is B1.3 years. The N/P, Si/P, and Si/C ratios are 15, 25, and 0.15, respectively. The subtropical Pearl River study is also compared to other large rivers with regard to differences in both natural processes (i.e., weathering rates) and anthropogenic influences (i.e., nutrient input) between these different river-estuary systems.
Estuarine chemistry, Carbon cycle, Nutrient cycles, Biological production, Continental shelves, Dissolved inorganic carbon, Alkalinity
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【期刊论文】Comment on "Enhanced Open Ocean Storage of CO2 from Shelf Sea Pumping"
戴民汉, Wei-Jun Cai, Minhan Dai
SCIENCE VOL 306 26 NOVEMBER 2004,-0001,():
-1年11月30日
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戴民汉, Weidong Zhaia, Minhan Daia, b, *, Wei-Jun Caic, Yongchen Wangc, Zhaohui Wangc
Marine Chemistry 93(2005)21-32,-0001,():
-1年11月30日
We investigated distributions of surface water CO2 partial pressure (pCO2), dissolved oxygen (DO) and associated carbonate parameters in the Pearl River estuary, a large subtropical estuary under increasingly anthropogenic pressure in China, in the summer of 2000 and late spring of 2001. pCO2 levels, measured underway using a continuous measurement system, were high during both seasons, with levels of>4000 Aatm at salinity <0.5. pCO2 distribution overall mirrored DO across the salinity gradient. Using the linear relationship between excess CO2 and apparent oxygen utilization (AOU) in surface water, we conclude that aerobic respiration is the most important process in maintaining such high pCO2 measured upstream. The material being respired is likely in a close association with the organic pollutants discharged into the system. Based on the measured excess CO2 vs. AOU plots, we estimate that the upper limit of pCO2 should be ~7000 Aatm in the Pearl River estuary assuming that CO2 was produced solely by aerobic respiration.
Carbon dioxide, Carbon cycle, Respiration, Outgassing, Estuary, China, Pearl River estuary
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戴民汉, Weidong Zhaia, Minhan Daia, b, *, Wei-Jun Caic, Yongchen Wangc, Huasheng Honga
Marine Chemistry 96(2005)87-97,-0001,():
-1年11月30日
The distribution of pCO2 in the surface waters of the northern South China Sea (NSCS) was examined in the summer of 2000, the spring of 2001 and the late fall of 2002. For the offshore region N100 km away from the coastline, surface water pCO2 varied within a range of 360-C450 Aatm during all the surveys. Nevertheless, they were generally higher than atmospheric pCO2.Sea-Cair DpCO2 ranged in 50-C100 Aatm in the summer, 0-C50 Aatm in the spring and 0-C90 Aatm in the late fall. Average sea-toair CO2 flux was 7 mmol CO2m-2 day-1 in the summer and 1-C3 mmol CO2m-2 day-1 in the spring and fall. Nearshore pCO2 showed a very dynamic pattern likely associated with the regional hydrodynamic settings, yet again pCO2 in the surface water overall exceeded the air pCO2. Data from this study thus suggests that the NSCS served as a source of atmospheric CO2. Seasonal variations of the pCO2 in the NSCS outer shelf and slope surface waters were significantly influenced by sea surface
Air-sea flux, Carbon dioxide, Marginal sea, South China Sea
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戴民汉, Kara Sea, Russia, Min-Han Dai, Jean-Marie Martin
Earth and Planetary Science Letters 131(1995)127-141,-0001,():
-1年11月30日
Dissolved and colloidal trace element concentrations (Cd, Cu, Fe, Ni and Pb) were determined in the Ob and Yenisey river-estuary systems and in the adjacent Kara Sea in September 1993. The data show a natural low concentration level of 'dissolved' (<0.4μm) trace metals (Cd, Cu, Fe, Ni and Pb) in the two rivers and in the Kara Sea as compared to world unpolluted rivers and the central Arctic Ocean, suggesting that the region studied is pristine with respect to trace metals. The pathway of trace metals transported from rivers to the ocean seems to be complicated, and largely influenced by biogeochemical processes taking place in the estuarine mixing zone. Colloidal material (104 Daltons-0.4μm), in addition to its significant contribution to the so-called 'dissolved' fraction, has becn shown to play a fundamental role in determining the behaviour of both conservative and non-conservative trace metals during estuarine mixing. Hence, colloids may control to a large extent the fate of 'dissolved' trace metals as well as their net input from the rivers to the Kara Sea.
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戴民汉, Jean-Marie Martin and Min-Han Dai, Gustave Cauwet
Limnol. Oceanogr., 40 (1), 1995, 119-131,-0001,():
-1年11月30日
Colloidal organic C and trace metals from the waters of a highly productive coastal environment (the Venice Lagoon, Italy) have been separated by a cross-flow ultrafiltration device. On average, 18% of organic C, 34% of Cd, 46% of Cu, 87% of Fe, 18% of Ni, 58% of Pb, and 54% of Mn which previously would have been considered in the dissolved phase are actually associated with colloidal material. Thus, past studies overestimate the dissolved trace-metal concentration in the nearshore environment. Compared to total concentration, the proportion of the colloidal fraction represents on average 15% of organic C, 18% of Cd, 28% of Cu, 11% of Fe, 11% of Ni, 29% of Pb, and 12% of Mn. This fraction acts differently from the truly dissolved and macroparticulate phases. The behavior of organic C and trace elements during mixing between freshwater and seawater is more complicated than expected when a colloidal fraction is involved. The flocculation of colloids, encountered normally during estuarine mixing, is not very significant on the time scale of mixing in the lagoon. Conversely, the interaction between colloidal and truly dissolved phases seems important. The partitioning of trace metals between different fractions of organic C appears variable, Fe and Mn are preferentially tied to macroparticulate organic matter, and Cu and Cd are preferentially tied to colloidal organic matter in seawater. Truly dissolved organic C appears to be important for Ni. Pb is mainly associated with macroparticulate organic matter at most stations except in the highly productive region where Pb prefers colloidal organic C.
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