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PubMed | Renmin University of China, China Agricultural University, Beijing Forestry University and Changjiang Water Resources Commission Changjiang Institute of Survey
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2016

A novel process coupling photosynthetic bacteria (PSB) with electrodeionization (EDI) treatment was proposed to treat high ammonia wastewater and recover bio-resources and nitrogen. The first stage (PSB treatment) was used to degrade organic pollutants and accumulate biomass, while the second stage (EDI) was for nitrogen removal and recovery. The first stage was the focus in this study. The results showed that using PSB to transform organic pollutants in wastewater into biomass was practical. PSB could acclimatize to wastewater with a chemical oxygen demand (COD) of 2,300 mg/L and an ammonia nitrogen (NH4(+)-N) concentration of 288-4,600 mg/L. The suitable pH was 6.0-9.0, the average COD removal reached 80%, and the biomass increased by an average of 9.16 times. The wastewater COD removal was independent of the NH4(+)-N concentration. Moreover, the PSB functioned effectively when the inoculum size was only 10 mg/L. The PSB-treated wastewater was then further handled in an EDI system. More than 90% of the NH4(+)-N was removed from the wastewater and condensed in the concentrate, which could be used to produce nitrogen fertilizer. In the whole system, the average NH4(+)-N removal was 94%, and the average NH4(+)-N condensing ratio was 10.0.


Wang J.,Hohai University | Li J.N.,Changjiang Water Resources Commission Changjiang Institute of Survey | Zhu S.,Hohai University
Advanced Materials Research | Year: 2014

This paper discussed the mechanism of dilatancy in coarse grained soils. Large-scale triaxial tests were also conducted to study the dilatancy law of coarse grained soils. Based on the results of the previous studies, it is found that plastic potential function proposed by Lade can fit the test results well. Lade's dilatancy rule was then applied to a practical two-yield-surface model. Elastoplastic formula of the two-yield-surface model was also deduced in detail. The new model was verified with several groups of different materials. Results showed that this model could predict the behaviors of coarse grained soils well. © (2014) Trans Tech Publications, Switzerland.


PubMed | Changjiang Water Resources Commission Changjiang Institute of Survey, Sun Yat Sen University and CAS South China Botanical Garden
Type: | Journal: Scientific reports | Year: 2016

Tree mortality and recruitment are key factors influencing forest dynamics, but the driving mechanisms of these processes remain unclear. To better understand these driving mechanisms, we studied forest dynamics over a 5-year period in a 20-ha sub-tropical forest in the Dinghushan Nature Reserve, South China. The goal was to identify determinants of tree mortality/recruitment at the local scale using neighborhood analyses on some locally dominant tree species. Results show that the study plot was more dynamic than some temperate and tropical forests in a comparison to large, long-term forest dynamics plots. Over the 5-year period, mortality rates ranged from 1.67 to 12.33% per year while recruitment rates ranged from 0 to 20.26% per year. Tree size had the most consistent effect on mortality across species. Recruitment into the 1-cm size class consistently occurred where local con-specific density was high. This suggests that recruitment may be limited by seed dispersal. Hetero-specific individuals also influenced recruitment significantly for some species. Canopy species had low recruitment into the 1-cm size class over the 5-year period. In conclusion, tree mortality and recruitment for sixteen species in this plot was likely limited by seed dispersal and density-dependence.


Yan B.,Huazhong University of Science and Technology | Guo S.,Wuhan University | Yu W.,Changjiang Water Resources Commission Changjiang Institute of Survey
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2013

Coincidence of flood hydrograph can be generalized as mathematical constraints of date interval and magnitude for flood occurrence. A multivariate hydrological analysis model was developed to estimate the flood coincidence risk between the Yangtze and the Qing River. In this model, the mixed von Mises distribution was introduced to describe the interval, and a Copula function was adopted to establish a trivariate distribution of the 15-days flood volume and its interval for each river. By this model, a coincidence risk of 21. 9% was evaluated, the risk characteristics for different combinations of flood frequencies of the two rivers were analyzed. The results would provide a technical support to the united compensational operation of reservoirs on the Yangtze and the Qing River.


Yang G.S.,Wuhan University | Yang G.S.,Changjiang Water Resources Commission Changjiang Institute of Survey | Huang J.S.,Wuhan University | Li J.,Changjiang Water Resources Commission Changjiang Institute of Survey | Yin W.,Changjiang Water Resources Commission Changjiang Institute of Survey
Advanced Materials Research | Year: 2014

Danjiangkou Reservoir and its upstream tributaries as water resource area is of strategic importance for the Mid-route of South-to-North Water Transfer Project. Water conservation and water purification is the key measures for sustainable water diversion. Green water management as a new technologies to achieve water conservation and water purification has a broad application prospects. In this research, green water management was studied in the Upper Du watershed. ArcSWAT model was used to assess quantity of green water resource. By adjusting the model parameters, the efficiency of different green water management scenarios on water and soil conservation were simulated. The results of the study indicate that the quantity of green water in the Upper Du is about 5.588 billion cubic meters. Mulching is a better green water management way that more suitable for water and soil conservation in the Danjiangkou Water Resource Area. This research can provide a reference for water resource protection and management in Water Resource Area of the Mid-route of South-to-North Water Transfer. © (2014) Trans Tech Publications, Switzerland.


Tang X.,Changjiang River Scientific Research Institute | Wu M.,Changjiang River Scientific Research Institute | Yang W.,Changjiang River Scientific Research Institute | Yin W.,Changjiang Water Resources Commission Changjiang Institute of Survey | And 4 more authors.
Water, Air, and Soil Pollution | Year: 2012

Water monitoring results of the Danjiangkou Reservoir indicated that total nitrogen and total phosphorus concentrations are high and therefore worse than required for central drinking water supplies. Nutrients including nitrogen and phosphorus accumulated in the bank cultivated land were greater than those contained within the river estuary sediment as well as in the reservoir bay sediment. This implies that high concentrations of loosely exchangeable phosphorus (166.53 mg/kg) in cultivated land could, after the completion of the dam heightening project, easily lead to the development of algal blooms. Serious water and soil loss occurring in the reservoir area will promote the transportation of non-point source pollution mainly caused by untreated agricultural domestic wastewater, chemical fertilizer and livestock farming, which accounted for more than 50%of the total basin's nutrient input loads. Ecological control techniques were therefore the first choice for nutrient reduction and water quality guarantee in the Danjiangkou Reservoir. In order to guide the ecological restoration process, leading international ecological methodologies were summarized and compared, taking into consideration aspects of engineering, as well as ecological, biological, environmental and economic advantages and disadvantages. Finally, novel ecological filtration and a purification dam were designed for eutrophication control. © Springer Science+Business Media B.V. 2011.


Liu Y.Y.,Changjiang Water Resources Commission Changjiang Institute of Survey | Liu B.J.,Hubei Provincial Water Resources and Hydropower Planning Survey and Design Institute
Applied Mechanics and Materials | Year: 2014

Hydrologic responses to climate change have become a great challenge and attracted widespread attention of the researchers. The mountainous Qingyi River watershed in the southwest, China, had experienced significant climate change in the past three decades. It is necessary to investigate the hydrologic responses to these changes. Therefore, the effect of climate change on evapotranspiration (ET), surface runoff, baseflow and streamflow were assessed using Variable Infiltration Capacity (VIC) hydrologic model. The Mann-Kendall test analysis was first used to identify the long-term change in precipitation and temperature over the period of 1980-2010. It revealed that there is a significant change in annual temperature particularly in February, March, July and September, whereas an insignificant change in annual precipitation was founded. Hydrologic simulations show that hydrologic responses to climate change were varied from region to region. Surface runoff was more sensitive than ET and baseflow. Monthly variation of the hydrologic processes, especially the change in surface runoff, was mainly attributed to seasonal variation in precipitation. The results of this research can be a useful source of information for the decision making in water resources management and protection. © (2014) Trans Tech Publications, Switzerland.


Qiu L.,Changjiang Water Resources Commission Changjiang Institute of Survey | Zhai H.J.,Changjiang Water Resources Commission Changjiang Institute of Survey
Applied Mechanics and Materials | Year: 2014

Chishui River, a first-order south tributary of upper Yangtze River, extends cross Sichuan, Yunnan and Guizhou provinces and is famous as the “eco-river with a lot of endemic fishes”, “Beauty River with natural scenic landscapes”, “Chinese famous liquors river with Maotai” and “hero river”. According to the existing problems in Ecological Environment of the Chishui River, the ecological compensation mechanism was established and the compensation of the main watershed ecology, ecological compensation object, ecological compensation standards and ecological compensation ways were determined, for protecting the environment requirements of the rare and unique fish and Liquor industry production of Yangtze River. © (2014) Trans Tech Publications, Switzerland.


Wang W.L.,Hubei Engineering University | He J.,Changjiang Water Resources Commission Changjiang Institute of Survey | Qu W.L.,Hubei Engineering University
Applied Mechanics and Materials | Year: 2014

This paper proposes a method to quantitative assess the impact of welding residual stress to structure's cumulative fatigue damage. We use ANSYS finite element software to eliminate the welding temperature field and welding stress field, and by changing the load order, preheat consider we can get the welding residual stress of different eliminate proportion. Based on critical damage plane method we finish the welding earplant joint s wind-induced cumulative fatigue damage by different eliminate proportion of welding residual stress. © (2014) Trans Tech Publications, Switzerland.


Li J.,Changjiang Water Resources Commission Changjiang Institute of Survey | Yin W.,Changjiang Water Resources Commission Changjiang Institute of Survey
Applied Mechanics and Materials | Year: 2014

Danjiangkou Reservoir and its upstream tributaries as water resource area is of strategic importance for the Mid-route of South-to-North Water Transfer Project. Ecological and water security are the key measures for sustainable water diversion. Green water management as a new technology to achieve water conservation and water purification has a broad application prospects. In this research, green water management such as bench terraces, contour tillage, mulching and stone line was studied in the Upper Du watershed. ArcSWAT model was used to assess effect of green water management on river base flow. The results show that four green water management measures activated the regulating action of “soil water reservoir”. Base flow in export section of Upper Du river basin is increased under different four green water management measures, and especially the base flow increased more obvious in non-flood season. That is helpful to improve the ecological security degree in water resources area. © (2014) Trans Tech Publications, Switzerland.

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