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Fang D.,Wuhan University of Technology | Chen S.,Yangtze Valley Water Environment Monitoring Center | Jiang M.,Wuhan University of Technology | Li Q.,Wuhan University of Technology | And 3 more authors.
Materials Science in Semiconductor Processing | Year: 2014

Anodic titanium oxide TiO2 nanotube membranes with one, two and three layers have been prepared by the anodic oxidation method via adjusting applied bias during the oxidation process in glycol electrolytes containing 0.25 wt% or 0.50 wt% NH4F. The morphologies of the as-prepared samples were presented in detail using scanning and transmission electron microscopy. The results indicated that the glycol electrolyte containing 0.25 wt% NH 4F yielded smooth double-walled nanotubes, and their tubes remained open in multilayers; while the glycol electrolyte containing 0.50 wt% NH 4F yielded single-wall nanotubes with ripples, and most of the nanotubes have closed bottoms. In the case of nanotubes with closed bottoms, it was proposed that the newly grown nanotubes on the succeeding layer formed in the gap between the nanotubes of the previous layer. In order to keep track of the growth of the nanotubes, samples were anodized for different periods of time from 1 to 90 min to study their formation process. Growth mechanisms were proposed for different morphologies. © 2013 Published by Elsevier Ltd. All rights reserved.


Tang W.J.,Hohai University | Tang W.J.,Yangtze River Scientific Research Institute | Ren L.,Yangtze River Scientific Research Institute | Xu H.,Yangtze Valley Water Environment Monitoring Center | And 3 more authors.
Advanced Materials Research | Year: 2014

The contradiction between water shortage and social needs has become an important factor restricting economic development. As freshwater, flood could be used as the natural resources to resolve the problem of water shortage, and also has some environmental benefits. Taking Danjiangkou reservoir as example, we adopt dynamic control method of limited water level to discuss the potential socioeconomic benefits of flood utilization. © (2014) Trans Tech Publicutions, Switzerland.


Guo Z.,CAS Wuhan Institute of Hydrobiology | Liu J.,CAS Wuhan Institute of Hydrobiology | Lek S.,CAS Wuhan Institute of Hydrobiology | Li Z.,CAS Wuhan Institute of Hydrobiology | And 3 more authors.
Hydrobiologia | Year: 2015

Although many goby species have become widely established outside of their native ranges, little is known yet about invasive population biology. The age, growth and population dynamics of two introduced goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) were quantified in Lake Erhai (southwest China) with the general aim to improve empirical knowledge and management strategies. The results revealed that their lifespan ranges 2 years. The size and time at sexual maturity for R. cliffordpopei was lower than for R. giurinus. R. cliffordpopei displayed higher total mortality, fishing mortality and exploitation rates than R. giurinus, whereas the natural mortality of R. cliffordpopei was lower than that of R. giurinus. The catch per unit effort of benthic fyke nets was low from April to June in R. cliffordpopei and from July to September in R. giurinus, whereas it was high from July to September in R. cliffordpopei and from April to June in R. giurinus. Thus, several specific strategies are suggested to improve the cost-efficiency of the current management practices related to the mesh size of benthic fyke nets used for physical removals, the timing of deployment of control actions and the use of synergic control methods. © 2015 Springer International Publishing Switzerland


Qu G.,Wuhan University | Qu G.,Changjiang River Scientific Research Institute | Xu H.,Yangtze Valley Water Environment Monitoring Center | Guo X.H.,Changjiang River Scientific Research Institute | Zhu Y.H.,Changjiang River Scientific Research Institute
Procedia Engineering | Year: 2012

Based on the measured data from 1957 to 2007 in Jingjiang river, this paper analyzed the water level change in Jingjiang river in low water and bank-full discharge, and then established the relationship between the value of water level change and river sediment scour-silt amount with the measured topographic data after the cut-off. The results show that the relations are well at Shashi and Xinchang stations while the correlation is not obvious at Jianli station. Finally, the paper analyzed the influencing factors of water level change in Jingjiang river in view of the water and sediment changes before and after the impoundment of Three Gorges reservoir and found that the recent water level change in Jingjiang river is mainly caused by the incoming sediment concentration change in the main stream of Changjiang river. © 2012 Published by Elsevier Ltd.


Hu M.,China Institute of Water Resources and Hydropower Research | Zhou H.,China Institute of Water Resources and Hydropower Research | Wang Y.,China Institute of Water Resources and Hydropower Research | Wang Y.,Yangtze Valley Water Environment Monitoring Center | And 5 more authors.
Water Science and Technology | Year: 2014

Investigations of the phytoplankton, zooplankton, zoobenthos and aquatic vegetation in Lake Qiluhu were carried out in February, 2009. Over the whole lake, 13 sampling sites were set up for the analysis of phytoplankton and zooplankton, and 22 profiles for the collection of macrophytes and zoobenthos. In the survey, 7 phyla, 65 algae species were identified. The average abundance of phytoplankton was 7.16 × 108 cells/L, and the dominant specie was Limnothrix redekei. No obvious surface accumulation of algae was detected. The concentration of Chlorophyll a ranged from 85 to 101 μg/L, and the average value was 93 μg/L. Nineteen species of zooplankton were observed, including 4 species of rotifers, 6 species of cladocerans and 9 species of copepods. Copepods were the dominant species, their abundance reaching 68%, whilst Cladocerans took second place with an abundance proportion of 28%. Six species of submerged vegetation were identified: Potamogeton Pectinatus, Myriophyllum, Elodea Canadensis, Ceratophyllum demersum and Potamogeton crispus. Amongst them, the dominant vegetation was P. Pectinatus, the biomass of which was up to 63% of the total biomass. Emerged macrophytes were cluster distributed across the whole lake, mainly consisting of Scirpus tabernaemontani, phragmites communis and cane shoots. Unfortunately, no living zoobenthos were found at the sites. The results indicated that, in Lake Qiluhu, the abundance of phytoplankton was maintained at a high level. The ecological function of submerged vegetation was gradually being lost because of its low standing crop and coverage, and the benthic animal habitat was severely damaged. © IWA Publishing 2014.


PubMed | Yangtze Valley Water Environment Monitoring Center, China Institute of Water Resources and Hydropower Research, Hebei University of Engineering and CAS Wuhan Institute of Hydrobiology
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2014

Investigations of the phytoplankton, zooplankton, zoobenthos and aquatic vegetation in Lake Qiluhu were carried out in February, 2009. Over the whole lake, 13 sampling sites were set up for the analysis of phytoplankton and zooplankton, and 22 profiles for the collection of macrophytes and zoobenthos. In the survey, 7 phyla, 65 algae species were identified. The average abundance of phytoplankton was 7.16 10(8) cells/L, and the dominant specie was Limnothrix redekei. No obvious surface accumulation of algae was detected. The concentration of Chlorophyll a ranged from 85 to 101 g/L, and the average value was 93 g/L. Nineteen species of zooplankton were observed, including 4 species of rotifers, 6 species of cladocerans and 9 species of copepods. Copepods were the dominant species, their abundance reaching 68%, whilst Cladocerans took second place with an abundance proportion of 28%. Six species of submerged vegetation were identified: Potamogeton Pectinatus, Myriophyllum, Elodea Canadensis, Ceratophyllum demersum and Potamogeton crispus. Amongst them, the dominant vegetation was P. Pectinatus, the biomass of which was up to 63% of the total biomass. Emerged macrophytes were cluster distributed across the whole lake, mainly consisting of Scirpus tabernaemontani, phragmites communis and cane shoots. Unfortunately, no living zoobenthos were found at the sites. The results indicated that, in Lake Qiluhu, the abundance of phytoplankton was maintained at a high level. The ecological function of submerged vegetation was gradually being lost because of its low standing crop and coverage, and the benthic animal habitat was severely damaged.


Wang C.,Changjiang Water Resource Protection Institution | Zhai W.,Yangtze Valley Water Environment Monitoring Center | Yin W.,Changjiang Water Resource Protection Institution | Shan B.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Pollution Research | Year: 2015

Oxygen penetration is a key determinant of sediment nitrification rates. In this study, we analyzed the effect of oxygen penetration on the sediment nitrification rate based on sediment oxygen profiles. Six sediments were designed to produce different oxygen profiles by adding different amounts of silica gel to the collected river mud. The oxygen profiles in the sediment were detected using a voltammetric microelectrode. With increased mud content, the sediment oxygen penetration depth decreased from 8.3 to 2.6 mm, and the oxygen concentration in the overlying water and at the sediment-water interface also showed a decreasing trend. The measured nitrification rate displayed a quadratic pattern that changed with the increase in mud content. Based on the detected oxygen profiles, the nitrification rate at each depth was calculated and summed to obtain the bulk sediment nitrification rate. The bulk sediment nitrification rate showed a consistently changing pattern with the measured rate. Oxygen profiles used to calculate nitrification rates could be approximated by the penetration depth (δ). The resulting nitrification model based on δ could explain the limiting role of oxygen penetration in sediment nitrification. © 2015 Springer-Verlag Berlin Heidelberg


Wang Y.,CAS Wuhan Institute of Hydrobiology | Wang Y.,Yangtze Valley Water Environment Monitoring Center | Wang Z.,CAS Wuhan Institute of Hydrobiology | Wu W.,CAS Wuhan Institute of Hydrobiology | And 4 more authors.
Fresenius Environmental Bulletin | Year: 2010

For a natural lake, there are usually two stable states, a clean state and aturbid state. However, there exists an alternative state, which is unstable and can shift to either a clean or a turbid state depending on varied environmental factors. In this paper, we report a lake undergoing a pattern of seasonal shifting.We found that Lake Xingyun appeared clean in winter with low level of nutrients, low Chlorophyll a (Chl-a) and high secchi depth (SD). However, during summer, thelake turned into turbid with higher level of nutrients and Chla, but lower SD. Inclose response to environmental changes, phytoplankton population of the lake also adopted a pattern of seasonal shift. The order of the seasonal appearances of the dominant populations was as follows: Cyanophyta and Cryptophyta in spring, Microcystis in summer, Melosira in autumn, and Chlorophyta in winter. Our data clearly indicate that Lake Xingyun stayed in clean state in winter but became turbid in summer, and 0.07-0.135mg/L can be considered as the total phosphorus (TP) threshold concentration for Lake Xingyun's alternation between those two states. We also found that both TP and water temperature were the major factors influencing the phytoplankton biomass and its succession. In addition, wind also played a significant role in promoting the dominance of Chlorophyta in winter. In conclusion, Lake Xingyun, represents an alternative state lake with a certain nutrient level, can undergo a seasonal regime shift. Temperature change is the primary force thatdrives Lake Xingyun to shift its regime state.


Wang C.,Changjiang Water Resource Protection Institution | Zhai W.,Yangtze Valley Water Environment Monitoring Center | Shan B.,CAS Research Center for Eco Environmental Sciences
Environmental Science and Pollution Research | Year: 2016

Dissolved oxygen (DO) microprofiles of prepared sediments from 24 sampling sites in the Fuyang River were measured using a gold amalgam microelectrode in this study. The measured microprofiles can be divided into four types. In type I profiles, DO kept constant in the overlying water and decreased smoothly in the pore water; in type II profile, DO showed fluctuation in the pore water; in type III profiles, DO showed peak in the SWI; in type IV profiles, DO decreased obviously in the overlying water. Type I profiles indicated the absence of benthic organisms and thus the degradation of the sediment habitat. Type II and III profiles indicated the activity of benthic animal and epipelic algae, which is common in the healthy aquatic sediment. Type IV profiles indicated that the excessive accumulation of pollutants in the sediment and thus the serious sediment pollution. There are nine sites showing type I profile, three sites showing type II profile, nine sites showing type III profile, and three sites showing type IV profile in the Fuyang River. The dominance of type I and appearance of type IV indicated that sediment oxygen consumption processes in the Fuyang River were strongly influenced by the sediment pollutants release and the vanish of benthic organisms. The pharmacy, metallurgy, and curriery industries may contribute to the sediment deterioration and thus to the occurrence of type I and type IV oxygen profiles in the Fuyang River. © 2016 Springer-Verlag Berlin Heidelberg


PubMed | Changjiang Water Resource Protection Institution, Yangtze Valley Water Environment Monitoring Center and CAS Research Center for Eco Environmental Sciences
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

Dissolved oxygen (DO) microprofiles of prepared sediments from 24 sampling sites in the Fuyang River were measured using a gold amalgam microelectrode in this study. The measured microprofiles can be divided into four types. In type I profiles, DO kept constant in the overlying water and decreased smoothly in the pore water; in type II profile, DO showed fluctuation in the pore water; in type III profiles, DO showed peak in the SWI; in type IV profiles, DO decreased obviously in the overlying water. Type I profiles indicated the absence of benthic organisms and thus the degradation of the sediment habitat. Type II and III profiles indicated the activity of benthic animal and epipelic algae, which is common in the healthy aquatic sediment. Type IV profiles indicated that the excessive accumulation of pollutants in the sediment and thus the serious sediment pollution. There are nine sites showing type I profile, three sites showing type II profile, nine sites showing type III profile, and three sites showing type IV profile in the Fuyang River. The dominance of type I and appearance of type IV indicated that sediment oxygen consumption processes in the Fuyang River were strongly influenced by the sediment pollutants release and the vanish of benthic organisms. The pharmacy, metallurgy, and curriery industries may contribute to the sediment deterioration and thus to the occurrence of type I and type IV oxygen profiles in the Fuyang River.

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