Dongtinghu Lake Ecological Observation and Research Station DEORS

Yueyang, China

Dongtinghu Lake Ecological Observation and Research Station DEORS

Yueyang, China
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Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wu Z.,Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed | Wang S.,Chinese Research Academy of Environmental Sciences | And 2 more authors.
Journal of Hazardous Materials | Year: 2017

Diffusive gradients in thin films (DGT) technique has been newly designed for the identification of formation mechanisms of “internal phosphorus (P)-loading” and the numerical simulation of P exchange at DGT/sediment interface in Lake Dianchi. The primary mechanism was Fe-redox controlled P release from Fe-bound P in sediments, which was revealed by CDGT (P and Fe), total P (Fe) and P (Fe) fractions in NH4Cl and BD phases in sediments and their relationships at sites (N-T). The breakdown of algae biomass in the top layer of sediments at sites (O-T) and the coupled P/Fe/sulfur reactions at two depths at site N played a minor role in P release. The “internal P-loading” was calculated to be 19.23 t a−1, which was 3.0% of the “entering P-loading”. At sites (1–9), DGT induced flux in sediments (DIFS) model for P was used to derive curves (i) the resupply parameter (R) against deployment time and (ii) the dissolved/sorbed concentrations against the distance at DGT/sediment interface, the variation characters of which were controlled by kinetics and sediment-P pool. Sulfide microniches in sediments related to P release were evaluated by computer imaging densitometry (CID). DGT-DIFS-CID should be a reliable method to reveal P mobilization in lake sediments. © 2017 Elsevier B.V.


Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wang S.,Chinese Research Academy of Environmental Sciences | Wang S.,Dongtinghu Lake Ecological Observation and Research Station DEORS | And 5 more authors.
Environmental Science and Pollution Research | Year: 2015

Labile P, Fe, and sulfide with the high spatial resolution in sediment porewater of five sites (A–E) of Dianchi Lake (China) were measured at same locations using AgI/Chelex-100, Chelex-100, and ferrihydrite DGT (diffusive gradients in thin films) probes. DGT derived P/Fe/S concentrations in sediment porewater on millimeter or sub-millimeter scale in order to reveal the element remobilization process and the mechanism of “internal P-loading” of sediments in Dianchi Lake. Decomposition of alga biomass in the uppermost sediment layer and the reductive dissolution of Fe-bound P in the anoxic sediment were the two main processes causing P release. A dynamic numerical model-DIFS (DGT-induced flux in sediments) was used to assess sediment-P reactivity (capacity of solid pool and rate of transfer) and P release risk by kinetic parameter—TC (1089∼20,450 s), distribution coefficient—Kd (167.09∼502.0 cm3 g−1), resupply parameter—R (from 0.242 to 0.518), and changes of dissolved/sorbed concentration, R and M at the microzone of DGT/porewater/sediment. © 2015 Springer-Verlag Berlin Heidelberg


Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wu Z.,Beijing Normal University | He M.,Beijing Normal University | And 4 more authors.
Environmental Earth Sciences | Year: 2015

A passive sampling technique—diffusive gradients in thin films (DGT) was used to determine profiles of 14 metals on fine scale at SWI of two sites in Yingkou coast and to investigate biogeochemical process of Mn/Fe and other metals. Based on DGT concentration/flux and biogeochemical mechanism, remobilization character of metals in sediment profile was studied. Both profiles of two sites indicated sharp peaks of Fe and Mn at anoxic sediment, which verified redox process of Fe/Mn with large fluxes. Especially, very large peaks of Mn at −9.75 cm (7.239 × 10−4 µg cm−2 s−1) and Fe at −9.25 cm (1.420 × 10−3 µg cm−2 s−1) at site 2 corresponding with sulfide concentrations at same depths in profile were used for the calculation of saturation index to assess the solubility of metal sulfide. Other metals in certain segments of profiles at two sites indicated coupled geochemical process between them and Fe/Mn. DGT probe should be a reliable tool to measure multi-metals in sediment porewater and to assess geochemical process in coastal area. © 2014, Springer-Verlag Berlin Heidelberg.


Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wu Z.,Beijing Normal University | Wang S.,Chinese Research Academy of Environmental Sciences | And 4 more authors.
Environmental Earth Sciences | Year: 2015

The fine-scale profile (concentration/flux) of 14 metals at sediment/water interface (SWI) of Yingkou bay was measured by passive sampler-DGT (diffusive gradients in thin films) probe and HR-ICP-MS instrument. Fe profile in sediment porewater indicated redox reactions, which was verified by peaks at −6.75, −7.75, −8.75 and −11.75 cm. Mn profile in sediment porewater indicated redox-sensitive character with the continuous increase in profile from −3.75 to −5.75 cm, and the subsequent peaks at −6.25, −8.25, −9.75 and −11.25 cm. Both Fe and Mn profiles indicated low values at −10.25 cm, which was due to the formation of pyrite and the adsorption of Mn on it. The co-occurrence of some peaks and broad feature near peaks of trace metals and Fe/Mn at same depths of profiles indicated coupled geochemical process and co-remobilization. The diffusive fluxes of metals across SWI were also calculated and investigated. © 2014, Springer-Verlag Berlin Heidelberg.


Liu W.,Chinese Research Academy of Environmental Sciences | Liu W.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Liu W.,Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed | Wang S.,Chinese Research Academy of Environmental Sciences | And 14 more authors.
Environmental Earth Sciences | Year: 2015

In view of the problems of high P concentration in the sediments and low P concentration in the overlying waters of Erhai Lake (EH), an indoor static incubation experiment was performed to determine the P release characteristics of sediments at different depths. The differences in the P forms of the sediments before and after the incubation experiment were compared, and the impact of such forms on the characteristics of the P release of sediments at different depths and that of P release on the water quality of EH were also investigated. Results were as follows: (1) Dissolved organic P (DOP) is the main form of P released at the sediment–water interface of EH, which is approximately six times that of soluble reactive P (SRP), which indicates that the DOP release of sediments may have a more important impact on P composition and the content of the overlying water of EH than SRP. The release flux of the DOP of sediments at the surface layer is higher than that at the bottom layer. The vertical distribution of the release flux of SRP is characterized by an increase at the surface layer and a decline at the lower layer. (2) Different P release potentials exist for different forms of P in the sediments of EH. Among the different P forms, the loosely absorbed inorganic P (NH4Cl-rp) is the main source of SRP that is released from the sediments into the overlying waters. (3) The release flux of total P (TP) at the sediment–water interface of EH amounts to 114.2 t/a, which accounts for 87.2 % of the total external P input in the lake. Although the amount of the P release of sediments under indoor static simulation conditions is higher than that under real conditions, the trend of the P release of the sediments of EH is accurate. According to this result, the contribution of the sediment P release to the TP concentration of the overlying water is up to 31 %, reaching a concentration of 9.4 µg/L. The annual P release of the sediments of EH influences the P concentration in the overlying water. The contribution of the sediment P release to the TP concentration of overlying water in the northern part of EH is obviously higher than to that of the other parts. The water quality of this kind of lake can be improved by controlling the P release of sediments, particularly the release of OP. © 2015, Springer-Verlag Berlin Heidelberg.


Liu W.,Chinese Research Academy of Environmental Sciences | Liu W.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Liu W.,Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed | Wang S.,Chinese Research Academy of Environmental Sciences | And 8 more authors.
Environmental Earth Sciences | Year: 2015

Since the 1980s, Dianchi Lake Basin has been experiencing rapid social and economic development and accelerating urbanization. Hence, the water quality of Dianchi Lake is constantly deteriorating as a result of the great population burden and pollution loading. The problem of eutrophication and the large gap between supply and demand for water resources requires urgent resolution. Therefore, the changes in water quality in Dianchi Lake and their social impact, the economic development of the basin, and population aggregation on water quality are discussed in this paper. The history of the protection and pollution control of Dianchi Lake can be divided into three stages: (1) the initiation and exploration stage [from the Seventh Five-Year Plan (1986–1990) to the Ninth Five-Year Plan (1996–2000)], which focused on the construction of laws, regulations, policies, plans, and systems of environmental protection; (2) the difficulty tackling stage [from the Tenth Five-Year Plan (2001–2005) to the Eleventh Five-Year Plan (2006–2010)], during which the efficiency of pollution control increased considerably and the trend of water quality deterioration was reversed; and (3) the preliminary achievement stage [since the Twelfth Five-Year Plan (2011–2015)], in which the primary task was to actively explore new ways of combining pollution control, protection, and development of Dianchi Lake. The focus of future plans for pollution management in Dianchi Lake is also explored, and a reference is provided for protection and pollution management in the lake. © 2015, Springer-Verlag Berlin Heidelberg.


Wu Z.,Chinese Research Academy of Environmental Sciences | Wang S.,Chinese Research Academy of Environmental Sciences | Jiao L.,Dongtinghu Lake Ecological Observation and Research Station DEORS
Journal of Geochemical Exploration | Year: 2015

Element profiles/images in sediment porewater at five sites of Dianchi Lake (China) were measured by AgI/Chelex-100, ferrihydrite and Chelex-100 DGT (Diffusive gradients in thin films) probes for labile sulfide, metals and P. Based on DGT profiles, remobilization character and geochemical behavior of multi-elements at fine scale were assessed. Fe remobilization characters at five sites indicated the distinct Fe-reduction process. The correspondence of Fe and Cu/Al/Zn, and good linear correlation in profiles verified the co-release of them by Fe-redox process in some sites. The reduction of Fe (III) hydroxyoxide caused P-release from Fe-bound P in anoxic sediment and "internal P loading" character, which has been verified by the linear correlation (R =0.77) in the whole DGT-profiles of Fe/P and the co-existence of Fe/P peaks at same depths. The peak flux (1.13×10-6-1.10×10-5 μgcm-2 s-1), niche area (3.6×10-5-6.0×10-2 cm2), circularity (0.204-1.0) and RJM (4.02-6.62%) derived by CID (computer image densitometry) have revealed the existence of sulfide microniche in sediments. © 2015 Elsevier B.V.


Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wang S.,Chinese Research Academy of Environmental Sciences | Wang S.,Dongtinghu Lake Ecological Observation and Research Station DEORS | And 4 more authors.
Environmental Science and Pollution Research | Year: 2016

Diffusive gradients in thin films (DGT)-induced flux in sediments (DIFS) (DGT-DIFS) model for phosphorus (P) has been investigated to provide a numerical simulation of a dynamic system of the DGT–pore water–sediment in Dianchi Lake (China). Kinetic parameter—TC (33–56,060 s), distribution coefficient—Kd (134.7–1536 cm3g−1), and resupply parameter—R (0.189–0.743) are derived by DGT measurement, the sediment/pore water test, and the DIFS model. The changes of dissolved concentration in DGT diffusive layer and pore water and sorbed concentration in sediment, as well as the ratio of CDGT and the initial concentration in pore water (R) and mass accumulated by DGT resin (M) at the DGT–pore water–sediment interface (distance) of nine sampling sites during DGT deployment time (t) are derived through the DIFS simulation. Based on parameter and curves derived by the DIFS model, the P release-transfer character and mechanism in sediment microzone were revealed. Moreover, the DGT-DIFS parameters (R, TC, K−1, CDGT), sediment P pool, sediment properties (Al and Ca), and soluble reactive P (SRP) in overlying water can be used to assess “P eutrophication level” at different sampling sites with different types of “external P loading.” The DGT-DIFS model is a reliable tool to reveal the dynamic P release in sediment microzone and assess “internal P loading” in the plateau lake Dianchi. © 2016 Springer-Verlag Berlin Heidelberg


Zhao H.,Chinese Research Academy of Environmental Sciences | Zhao H.,Hebei North University | Wang S.,Chinese Research Academy of Environmental Sciences | Wang S.,Dongtinghu Lake Ecological Observation and Research Station DEORS | And 8 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2014

The organic matter (OM) content, composition and their adsorption-release characteristics towards phosphorus (P) of the sediment from different regions of Erhai Lake were investigated to reveal the effect of their OM content and composition on the adsorption-release characteristics of sediment P. Experimental results indicated that the release potential of sediment P was enhanced with the increase of their total organic matter (TOM) content. The Vmax and Qmax of the released sediment P increased with the increase of their light fraction of organic matter (LFOC), and the releasing equilibration time decreased with the increase of their active organic matter (ASOM). Their P releasing intensity was weakened with the increase of the LFOM/TOM ratio. The Vmax and Qmax of sediment P adsorption and adsorption efficiency increased with the increase of their TOM content. The adsorption equilibrium time decreased with the increase of their TOM content, and the adsorption intensity was strengthened with the increase of their ASOM. EPC0 content decreased with the increase of their ASOM. During the process of release and re-adsorption of sediment P, both their Qmax for P release and Vmax for re-adsorption increased with the increase of their TOM. When the TOM content in the two sediments was equivalent, they decreased with the increase of their ASOC content and the re-adsorption intensity decreased with the increase of their LFOM content. Adsorption-release capacity of sediment P was enhanced with the increase of their TOM. The adsorption-release equilibrium concentration decreased with the increase of their OM activity intensity. The releasing intensity and rate decreased with the increase of their OM decomposing degree, and the adsorption intensity and rate increased with the increase of their OM activity intensity.


Wu Z.,Chinese Research Academy of Environmental Sciences | Wu Z.,Dongtinghu Lake Ecological Observation and Research Station DEORS | Wang S.,Chinese Research Academy of Environmental Sciences | Wang S.,Dongtinghu Lake Ecological Observation and Research Station DEORS | And 2 more authors.
Journal of Geochemical Exploration | Year: 2015

Element profiles/images in sediment porewater at five sites of Dianchi Lake (China) were measured by AgI/Chelex-100, ferrihydrite and Chelex-100 DGT (Diffusive gradients in thin films) probes for labile sulfide, metals and P. Based on DGT profiles, remobilization character and geochemical behavior of multi-elements at fine scale were assessed. Fe remobilization characters at five sites indicated the distinct Fe-reduction process. The correspondence of Fe and Cu/Al/Zn, and good linear correlation in profiles verified the co-release of them by Fe-redox process in some sites. The reduction of Fe (III) hydroxyoxide caused P-release from Fe-bound P in anoxic sediment and "internal P loading" character, which has been verified by the linear correlation (R=0.77) in the whole DGT-profiles of Fe/P and the co-existence of Fe/P peaks at same depths. The peak flux (1.13×10-6-1.10×10-5μgcm-2s-1), niche area (3.6×10-5-6.0×10-2cm2), circularity (0.204-1.0) and RJM (4.02-6.62%) derived by CID (computer image densitometry) have revealed the existence of sulfide microniche in sediments. © 2015 Elsevier B.V.

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