Total concentrations and speciation of metals had been studied in TSP of Guiyang from April 2006 and January 2007, PR China. The average concentration ranged from 14.48 ng m(-3) for Cd to 1,161.45 ng m(-3) for Zn. The concentrations of Cd, Cr, Pb and Zn were significantly higher during winter than those at other seasons. The environmentally mobile fractions of Cd and Zn were the highest in the three stages. The highest proportion of Pb was the fraction that bound to carbonate and oxide. Cr and Cu were clearly restricted to the fraction that bound to silicate and organic matter.
Water samples were collected for 23 different stations along a cross section profile of an estuary extending over to adjacent sea. The collected water samples were filtered and analyzed for major-minor ions and strontium isotope using the standard procedure to understand the geochemical behaviors of major and minor elements. The normalized values indicated that all riverine elements were entering to adjacent coastal sea with some significant variations at the estuary. The seawater dilution and regression lines explain about the overall patterns for seven elements. Removal processes were detected on calcium, magnesium, strontium and sulfate in the estuarine region. No significant mineral precipitation observed to release magnesium with respect to calcium. Minor variations of strontium and sulfate ions could be attributed to the presence of organic matter in the study area. Comparing seven elements with total suspended matters revealed that the total suspended matters played crucial role in either adsorption or absorption of all the elements in estuary before it reaches to coastal sea. Mixing patterns of strontium isotope showed minimal non-conservative with an evidence of active geochemical process in the estuary.
Phytoplankton community structure and δ<sup>13</sup>C of dissolved inorganic carbon (DIC), particulate organic carbon (POC), and phytoplanktonic carbon (PPC), and the related hydro-chemical parameters have been seasonally investigated in the cascade reservoirs from the Wujiang River Basin. Average values of δ<sup>13</sup>C<sub>DIC</sub>, δ<sup>13</sup>C<sub>POC</sub> and δ<sup>13</sup>C<sub>PPC</sub> were −8.1±1.3‰, −29.6±2.8‰, and −30.9±4.5‰, respectively. Seasonal fluctuation of δ<sup>13</sup>C<sub>PPC</sub> was comparable to that of δ<sup>13</sup>C<sub>POC</sub> and larger than that of δ<sup>13</sup>C<sub>DIC</sub>. The δ<sup>13</sup>C<sub>PPC</sub> values showed a significant linear correlation with δ<sup>13</sup>C<sub>POC</sub>, indicating that endogenetic phytoplankton is the main source of POC in these cascade reservoirs. Compared to environmental factors such as temperature, taxonomic differences are the main factor influencing δ<sup>13</sup>C<sub>PPC</sub> in this study. As a result, the contribution of <i>Bacillariophyta</i> to the total phytoplankton showed a significant negative correlation with δ<sup>13</sup>C<sub>PPC</sub> and Δδ<sup>13</sup>C (δ<sup>13</sup>C<sub>PPC</sub>−δ<sup>13</sup>C<sub>DIC</sub>), respectively, suggesting that δ<sup>13</sup>C<sub>PPC</sub> can be used to discern the change of phytoplankton community structure although only two kinds of dominant algae (i.e. <i>Bacillariophyta</i> and <i>Chlorophyta</i>) facilitate achieving this relationship. This relationship will have an important significance in understanding evolvement of phytoplankton community structure with time using geochemical technique once it is confirmed at a larger scale in field study
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