[Response of Phytoplankton Functional Groups to Eutrophication in Summer at Xiaoguan Reservoir].

Hydrology and Water Resources Bureau of Guizhou Province, Guiyang 550002, China) Abstract: In order to explore the distribution characteristics of phytoplankton functional groups, eutrophication characteristics and response of phytoplankton functional groups to eutrophication in Xiaoguan Reservoir, phytoplankton and water samples were taken once a week from 25th July 2014 to 27th September 2014. The results showed that there were 22 phytoplankton functional groups, groups S1, D, J, B, G, MP, L₀, SN, X1, Y, Xph, F, T and W1 were comparatively common functional groups, Wherein, S1, D and J were the dominant functional groups. Weekly dynamics of phytoplankton functional groups were: S1-->S1-->S1-->S1-->S1--S1-->S1-->J/D/S1-->Sl1- >/1D.

[Effect of nano-TiO2 on the release and activation of mercury in sediment].

To investigate the effects of nano-TiO2 on mercury release and activation in sediment, flooding simulation experiments were conducted. The impacts of nano-TiO2 on total mercury and methylmercury concentrations in overlying water were analyzed. And the influences of nano-TiO2 on the migration and transformation of mercury were discussed based on changes of mercury speciation in sediment.

[Mercury dynamics of several plants collected from the water-level fluctuation zone of the Three Gorges Reservoir area during flooding and its impact on water body].

Submerged plants are a major source for the abnormal elevation of methylmercury in reservoir. Several specific plants (Echinochloa crusgalli, Cynodondactylon and Corn stover) were collected and inundated in a simulated aquatic environment in the laboratory for investigating the mercury (Hg) dynamics in plants and the release process into water, aiming to find out the properties of Hg dynamics of plants under inundation conditions and its impact on water body in the Water-Level Fluctuation Zone of the Three Gorges Reservoir Area. The results showed that the contents of total mercury in several plants were in the range of 9.

[Release of mercury from soil and plant in water-level-fluctuating zone of the Three Gorges Reservoir area and its accumulation in zebrafish].

To investigate the production, distribution and bioavailability of methylmercury (MMHg) in soil and plants of the water-level-fluctuating zone (WLFZ) of the Three Gorges Reservoir area, simulation experiments were conducted in laboratory. Results indicated that the level of total mercury (THg) in soil decreased with the lengthening of submerging time while that in water increased obviously. The level of MMHg in inundated soil and water increased, especially in the water treated by Echinochloa crusgalli and soils.

[Influence of light wavelength and intensity on the reduction of divalent mercury in aquatic system].

Laboratory experiments were conducted to investigate the photo-reduction of HgCI2, under various light wavelengths and intensities. The whole process was tracked by changing Hg0 concentrations in argon and Hg0 flux was calculated for qualitative and quantitative analysis; the rate order was determined by both differential and integral methods. The principal results indicated: Higher mercury emission flux was observed under shorter light wavelength and stronger intensity, which shows the important role of photoenergy in the reaction.

[Distribution and risk assessment of mercury species in soil of the water-level-fluctuating zone in the Three Gorges Reservoir].

To investigate pollution level and ecological risk of mercury in soils of the water-level-fluctuating zone in the Three Gorges Reservoir Region, 192 surface soil samples from 14 counties (districts) in Chongqing were obtained. Concentrations of THg and Hg species, bioavailable Hg were analyzed and discussed. Geoaccumulation index (I(geo)) and Håkanson potential ecological risk index (E(r)) were applied to assess the pollution status and potential ecological risk of THg and Hg species, respectively.

[Mercury fluxes from conifer-broadleaf forested field in central subtropical forest zone].

Total gaseous mercury fluxes of forested field soils in the subtropical forest zones, Chongqing, Southwestern China were continually monitored from April 2011 to March 2012 to provide insights into the characteristics of gaseous mercury flux with conifer-broadleaf forest covers. Samples were collected from surfaces of forest fields as the most representative terrestrial surfaces in Jinyun Mountain. Simultaneously, meteorological parameters at the soil level relating to GEM fluxes, such as soil temperature, air humidity, and solar radiation were analyzed, and variations of atmospheric GEM concentration were examined.

[Mercury speciation transformation in soil of the water-level-fluctuating zone in the Three Gorges area under alternative dry-wet condition].

The speciation transformation, influencing factors, as well as bioavailability of mercury (Hg) in soil of the water-level-fluctuating zone in the Three Gorges Reservoir Area were simulated. The results showed that Hg in soil under alternative dry-wet condition could be transformed and released. The total Hg content in the soil was decreased by 28.

[Effects of nitrate ion on monomethylmercury photodegradation in water body].

To study effects of nitrate (NO3(-)) on monomethylmercury (MMHg) photodecomposition (PD), laboratory experiments were conducted to investigate the role of NO3(-) in MMHg PD under various light radiations, and to examine effects of NO3(-) concentration gradients on MMHg PD rates and end products. We analysed the react processes according to Hg2+ concentration. The results indicated that in the reactor exposed to natural and ultraviolet radiation, and treated with NO3(-), the rates of MMHg PD were calculated to be 0.

[Characteristics of monomethylmercury photodegradation in water body].

To investigate the photochemical process of monomethylmercury (MMHg) in the water environment, laboratory experiments were conducted using artificial and visible light sources to confirm the effects of wavelength and light intensity on MMHg photodegradation (PD), and the reaction process of MMHg PD was discussed based on Hg(0) emission rate. The results indicated that Hg(0) was the end product of MMHg PD, and the light conditions had an effect on the rate constant of MMHg PD and Hg(0) flux. When the reactor was exposed to UV light conditions, the rate constant of MMHg PD increased with the decrease in wavelength and the increase in light intensity.

Vesical varices causing gross hematuria in a four-year-old girl.

Primary vesical varices are rare. We report a case of a 4-year-old girl who presented with recurrent gross hematuria secondary to primary vesical varices. Ultrasonography, enhanced computed tomography, and voiding cystourethrogram revealed a solid mass in the right wall of the bladder.

Cystic lymphatic malformation of bladder presenting as a pelvic mass.

We report a 5-year-old boy with a cystic lymphatic malformation (LM) of bladder, and the imaging characteristics of the lesion are reported. Cystic LM of the urinary system is rare, and a location in the bladder is extremely rare. The exact mechanism of the lesion that occurs in bladder is unknown.