[Effect of Ca Modified Biochar on the Chemical Speciation of Soil Phosphorus and Its Stabilization Mechanism].

To control of phosphorus release from soil after farmland inundation around the lake and reservoir， calcium modified biochar （Ca-BC） was prepared using the coprecipitation method. Through X-ray photoelectron spectroscopy （XPS）， X-ray polycrystalline powder diffraction （XRD）， adsorption experiments， and simulated culture experiments， the effects of Ca-based biochar on the fraction of soil phosphorus （P） and its stabilization mechanism were studied. The results showed that the adsorption process of Ca-based modified biochar conformed to Langmuir （ = 0.

[Speciation and Risk of Heavy Metals in Surface Sediments of Different Types of Water Bodies in Baiyangdian Lake].

The morphological characteristics of Cd, Cr, Cu, Ni, Pb, and Zn in sediments were analyzed using an improved BCR extraction method in four water types of Baiyangdian Lake:watercourse, trench, lake surface, and fish pond. The potential ecological risk index, secondary and primary phases, and risk assessment codes were used to systematically assess the pollution level and ecological risk of heavy metals in surface sediments. The results showed that:① the mean contents of heavy metals Cd, Cu, and Zn in the sediments were 0.

[Nitrogen Distribution and Inorganic Nitrogen Diffusion Flux in a Shallow Lake During the Low Temperature Period: A Case Study of the Baiyangdian Lake].

The distribution of inorganic nitrogen across the sediment-water interface in Baiyangdian Lake, the largest shallow lake in North China, was examined during the low temperature period. Furthermore, the influence of inorganic nitrogen diffusion flux in sediment porewater on the overlying water quality was analyzed. The results showed that the mean TN concentration in the surface water ranged from 4.

[Speciation Distribution and Risk Assessment of Heavy Metals in Sediments from the Yitong River City Area].

The total content and chemical speciation of Cd, Cr, Cu, Ni, Pb, and Zn in seven short cores sampled from the Yitong River from Changchun City were analyzed to assess the pollution levels and potential ecological risks of heavy metals in the sediments. The results demonstrated that the total contents of Cd, Cr, Cu, Ni, Pb, and Zn in sediments were 0.10-1.

[Arsenic Content and Speciation in the Surficial Sediments of Liangshui River in Beijing].

Arsenic (As) content and speciation in the surface sediments of the typical urban river ( Liangshui River) with unconventional water sources in Beijing were investigated by different methods, including BCR three-step sequential extraction procedure, enrichment factor (EF), risk assessment code (RAC) and sediment quality guidelines (SQGs). The results showed that total As contents in the surface sediments ranged from 2.18 mg x kg(-1) to 22.

[Research of the Stormwater Runoff and Pollution Characteristics in Rural Area of Yuhang District, Hangzhou].

In order to investigate the pollution characteristics of stormwater runoff in the southern developed rural region, the runoff samples were collected from four different underlying surfaces during three storm events in Caoqiao and Pujia Tou, which are two typical villages and are located in Yuhang District of Hangzhou. The content of nutrition (nitrogen and phosphorus) and heavy metals (Mn, Cu, Zn, Ni, Cr, Cd, As, Pb) in the simples were analyzed, and the difference of EMC ( event mean concentration) and pollution load of the contaminants in the runoff on different underlying surfaces were compared. The results showed that the EMC of TSS, COD, NH4(+)-N, TP and TN were 16.

[Bioretention Media Screening for the Removal of Phosphorus in Urban Stormwater].

Urban runoff is an increasingly important source of excess phosphorus (P) to local receiving waters. Bioretention, a promising technology for urban stormwater pollution treatment, was investigated to determine whether the mixture of purple soil and sand could adsorb sufficient P at low concentrations in urban stormwater. The TP concentrations of urban runoff from variously impervious areas in Chongqing City ranged from 0.

[Distribution of nitrogen and phosphorus in the sediments and estimation of the nutrients fluxes in Longjinghu Lake, Chongqing City, during the initial impoundment period].

Sediment cores from a newly formed urban lake (Longjinghu Lake in China's Chongqing City) were selected to study the vertical distribution characteristics of both nitrogen and phosphorus from the overlying water to porewater, and then fluxes of ammonia (NH4+ -N) and orthophosphate (PO(3-)(4)-P) from different areas of the lake were calculated using a one-dimensional transport-reaction model based on the Fick's First Law. The results showed that the mean ammonia concentrations in porewater of surface layers (0-5 cm) was 6. 13 mg-L-1 +/-3.

[Characterization and optimization of the NaOH-EDTA extracts for solution 31P-NMR analysis of organic phosphorus in river sediments].

Optimization and mechanism of NaOH-EDTA extraction solutions were studied in phosphorus (P) pollution river sediments, which were Fe, Al-rich sediment, by solution 31P nuclear magnetic resonance spectroscopy (31P-NMR). Different proportions of NaOH and EDTA showed different extraction efficiency on total P (TP) and organic P (Po) in the sediment. The concentration of Po in NaOH + EDTA extract was higher than that in NaOH extract.

[Forms and spatial distribution characteristics of nitrogen in Ziya River Basin].

In order to research the spatial distribution characteristics and pollution condition of nitrogen in water and sediment, the Ziya River Basin was selected as the study area. The results showed: the average TN concentration of all water body samples was 31.28 mg x L(-1), which was 15 times higher than the V-class standard of national surface water, where the NH(4+)-N accounted for about 79% of TN ratio, followed by total organic nitrogen (TON).

[Spatial distribution and ecological risk assessment of heavy metals in the estuaries surface sediments from the Haihe River Basin].

It is well known that the rivers in the Haihe River Basin have been seriously polluted. However, what is the present condition of the estuary pollution and how the polluted inland rivers affect the estuary areas are not clear. 10 main estuaries of the Haihe River Basin were selected to measure the contents of typical heavy metals (Pb, Cu, Zn, Cd, Cr and Ni) in the surface sediments and to analyze the spatial distribution of these heavy metals.

[Characteristics of heavy metal pollution in the sediments from Shahe Reservoir, the upper reach of the North Canal River].

Shahe Reservoir, in the upper reach of the North Canal River, was selected for researching on sediments heavy metals pollotion. History of the sediments was build and six heavy metals (Cr, Cu, Mn, Ni, Pb, Zn) were analyzed for distribution characteristics, the resoures of heavy metals were also studied by sediments enrichment factor and the relationship between heavy metal contents and socio-economic development in this region. The results showed that the 30 cm depth of the sediments represented the year of 1960, the time when Shahe Dam was built.

[Construct of Yangtze-Huai River rural areas ecological drainage system and its retention effect on pollutants].

Ecological drainage system (EDS) including ditches, ponds and wetland was constructed at the Paifangchen village on the north of Chaohu Lake, Anhui, and its retention effect on pollution was investigated. With the comprehensive function of sewage discharge, collecting and process, the system could intercept runoff pollutants effectively. The results acquired from 3 rainfall events showed that the retention rates of EDS to TSS, COD, TP and TN were 78.

[Nitrogen and phosphorus composition in urban runoff from the new development area in Beijing].

Stormwater runoff samples were collected from two impervious roof and road of the new development area in Beijing, during three rainfall events in an attempt to characterize the urban runoff and determine nitrogen and phosphorus composition. The outcomes are expected to offer the practical guidance in sources control of urban runoff pollution. The results indicated that the stormwater runoff from the studied area presented a strong first flush for all monitored events and constituents.

[Dynamic characteristics of nitrogen and phosphorus in the representative input tributaries of Danjiangkou Reservoir].

Three representative input tributaries of Danjiangkou Reservoir in the upper reach of Hanjiang River, the largest tributary of Yangtze River, were selected for annual water quality monitoring from April 2010 to April 2011, to analyze dynamic characteristics of nitrogen (N) and phosphorus (P) in the river mouth areas, and then to assess the states of nutrition by comprehensive trophic level index. The results showed that the annual average concentrations of total nitrogen (TN) and total phosphorus (TP) in Shendinghe River, receiving both industrial and domestic wastewater from Shiyan City, were 11.63 mg x L(-1) and 0.

[Research on stormwater runoff quality of mountain city by source area monitoring].

Stormwater runoff samples were collected from 10 source areas in Mountain City, Chongqing, during five rain events in an attempt to investigate the characteristics of runoff quality and influencing factors. The outcomes are expected to offer practical guidance of sources control of urban runoff pollution. The results indicated that the stormwater runoff of Mountain City presented a strong first flush for almost all events and constituents.

[Spatial distribution character of phosphorus fractions in surface sediment from Chaohu Lake].

Phosphorus fractions, organic matter and particle size of the surface sediment from Chaohu Lake were analyzed for spatial distribution and the risk of phosphorus release. The result showed that total phosphorus (TP) of surface sediment was 790 mg x kg(-1), which was 55% higher than that in 1980s, with 386 mg x kg(-1) higher in western lake and 211 mg x kg(-1) higher in eastern lake. NaOH-Pi of sediment ranged from 55 to 648 mg x kg(-1), and occupied average 25% of TP.

[Heavy metals distribution and risk assessment of sediments in the riverine wetland of Sanmenxia Reservoir].

The survey for contents and fractions of heavy metal in sediments of riverine wetland in Sanmenxia Reservoir were carried out. Sediment pollution index was applied to assess the potential ecological risk and mass fraction of heavy metal in surface sediment was conducted for release risk assessment. The results showed that the total concentrations of Cr, Ni, Cu, Zn, Cd and Pb ranged in 25.

[Ecological stoichiometric relationships of periphyton community elemental composition and variations of water quality in the Chaobai River].

Carbon (C), Nitrogen (N) and Phosphorus (P) of water and periphyton were analyzed in the Chaobai River to investigate how anthropogenic river pollution affected the periphyton community and its elemental composition. The results of this study showed that NH4(+) -N and NO(x)(-) -N accounted for 52%, 28% of TN in the Chaobai River, respectively, while 1.6%, 38% of TN in the Baihe River.

[Temporal and spatial variation of nitrogen and phosphorus and eutrophication assessment in downstream river network areas of North Canal River Watershed].

Based on the water quality survey for one year in the downstream river network areas of North Canal River Watershed, variation features of inorganic nitrogen (N) and phosphorus (P) were analyzed, and water eutrophication degree of river network areas was also assessed. The results showed that the average concentration of TN was 12.50 mg x L(-1) (NH4(+)-N, 67.

[Spatial and temporal variation of Fe and Mn in the stormwater wetland].

To study the purification mechanism and biogeochemical cycle of wetlands, the concentration of Fe/Mn and oxidation reduction potential (ORP) in the pore water were monitored in situ on the Wuhan Zoo stormwater wetland from 2004 to 2006. The results showed that the water level of the wetland was changed from -10 cm to 30 cm, and the range of ORP was-120-220 mV. The elements of sulfur, iron and manganese were the main oxidation and reduction systems in the wetland.

[Organic phosphorus mineralization in the sediments under the impact of pH and temperature].

In the simulation, Bowman-Cole modified organic phosphorus fractionation system was used for the analysis of pH and temperature impact on organic phosphorus mineralization. The results showed that when pH were 6.5, 7.

[Organic phosphorus forms in the sediments in the downstream channel of North Canal River watershed].

Bowman-Cole modified organic phosphorus fractionation system was used for the analysis of the phosphorus (P) forms in the sediments in North Canal River. The results showed that the average concentrations variation of total phosphorus (TP), and total organic phosphorus (TOP) in the sediments were 654.9-1285.

[Transformation of inorganic nitrogen in slag-wetland during the start-up period].

Lab-scale subsurface flow slag-wetlands were constructed to study the removal efficiency and transformation processes of low-concentration inorganic N during the start-up period. As for ammonium-dominated wastewater, the removal rates of total nitrogen (TN), ammonium nitrogen (NH4(+)-N), nitrate nitrogen (NO3(-)-N) and nitrite nitrogen (NO2(-)-N) were 0.12 g x (m2 x d)(-1), 0.