Geographic pattern of phytoplankton community and their drivers in lakes of middle and lower reaches of Yangtze River floodplain, China.

Disentangling the relative contributions of deterministic and stochastic processes was critical to compressive understanding of underlying mechanism governing geographic pattern and assembly of phytoplankton community, while it was seldom performed in connected lakes under human pressure. Here, we investigated phytoplankton community pattern in relation to environmental and spatial factors over 81 lakes located in the middle and lower reaches of Yangtze River (MLYR) floodplain, where many lakes suffered from eutrophication and cyanobacterial blooms. A majority of MLYR lakes had higher phytoplankton abundance surpassing 10 cells/L and were dominated by common bloom-forming cyanobacterial genera, including Pseudanabaena, Microcystis, Merismopedia, Dolichospermum, Limnothrix, and Raphidiopsis.

[Denitrification Rates and -type Denitrifying Bacteria Community Structure Characteristics of Bulk and Rhizosphere Soil in Spring and Summer in the Alpine Wetlands of the Qinghai-Tibet Plateau].

Denitrification is a key process in the nitrogen cycle of ecosystems. Most existing studies of nitrogen emissions and denitrifying bacterial communities are carried out in ecosystems with significant human interference, yet few focus in natural ecosystems with low human disturbance. Here, the denitrification rates and characteristics of -type denitrifying bacterial communities in rhizosphere and bulk soils from alpine wetland plants at different altitudes(Tangke, Jiuzhi, Maduo, and Dari) and seasons(spring and summer) in the Yellow River source region of the Qinghai-Tibet Plateau were investigated.

[Research on the threshold of Chl-a in Lake Taihu based on microcystins].

Water samples were collected in Lake Taihu from June to October in 2013 in order to investigate the threshold of chlorophyll a (Chl-a). The concentrations of three microcystins isomers (MC-LR, MC-RR, MC-YR) were detected by means of solid phase extraction and high performance liquid chromatography-tandem mass spectrometry. The correlations between various MCs and eutrophication factors, for instance of total nitrogen (TN), total phosphorus (TP), chlorophyll a, permanganate index etc were analyzed.

[Measurement of dissolved organic nitrogen with nanofiltration pretreatment and its distribution characteristics in landscape water].

In this study, we present a nanofiltration (NF90, NF270) pretreatment to increase the precision of dissolved organic nitrogen (DON) measurements in water samples. The variations of DON measurements with and without NF pretreatment were investigated. And the effects on the removal of dissolved inorganic nitrogen (DIN) by NF90 and NF270 were compared.

[Rapid determination of chemical components in interstitial water of lake sediments using near-infrared spectroscopy].

The near infrared reflectance spectra (NIRS) of interstitial water samples of lake sediments in Chaohu lake were determined by near-infrared reflectance spectrometry. The respective near NIRS calibration models for predicting total nitrogen (TN), total organic carbon (TOC), phosphorus ( PO3(3-)), ammonia nitrogen(NH3-N) and silicate (SiO3-) were built using partial least squares (PLS) algorithm with two spectral pretreatment tools including, wavelet compression combining orthogonal signal correction (OSC) and orthogonal signal correction (OSC) combining wavelet compression. The correlation coefficients between measured values and predicted values in calibration set for TN, NH3-N, PO3(3-), TOC and SiO3(3-) were 0.

[Rapid determination of nutrient components in lake sediments using near infrared spectroscopy].

The lake sediments record important environmental evolution information of lake in recent 100 years. However, a rapid and precise combination analytical method measuring nutrient components in lake sediments can not be established. The near infrared reflectance spectra (NIRS) of sediment coring samples were determined by near-infrared reflectance spectrometry.

A hybrid inexact optimization approach for solid waste management in the city of Foshan, China.

An interval-parameter two-stage chance-constraint mixed integer linear programming (ITCMILP) model is provided for supporting long-term planning of solid waste management in the City of Foshan, China. The ITCMILP is formulated by integrating interval-parameter, two-stage, mixed integer, and chance-constraint programming methods into a general framework, and can thus deal with multiple uncertainties associated with model parameters, constraints and objectives. Three scenarios are examined, covering combinations of various system conditions and waste management policies.

[Phosphorus adsorption and regeneration of electric arc furnace steel slag as wetland medium].

The long-term phosphorus (P) adsorption and retention capacities of electric arc furnace (EAF) steel slag materials derived from one batch and a 278-d column experiments with a synthetic P solution were compared. The investigations of the regeneration of the P adsorption capacity by water level decrease was conducted. It was revealed column experiment on a long-term basis can determine P saturation of EAF accurately.

In situ simultaneous organics and nitrogen removal from recycled landfill leachate using an anaerobic-aerobic process.

An anaerobic-aerobic process including a fresh refuse landfill reactor as denitrifying reactor, a well-decomposed refuse reactor as methanogenesis reactor and an aerobic activated sludge reactor as nitrifying reactor was operated by leachate recirculation to remove organic and nitrogen simultaneously. The results indicated that denitrification and methanogenesis were carried out successfully in the fresh refuse and well-decomposed landfill reactors, respectively, while the nitrification of NH(4)(+)-N was performed in the aerobic reactor. The maximum organic removal rate was 1.

[Relationship between the nitrogen removal and oxygen demand in constructed wetlands].

A simplified model of sequential N transformations and sink was applied to investigate the relationship between the nitrogen removal and oxygen demand to verify the validity of full nitrification-denitrification mechanism in a newly-built multi-stages constructed wetlands. Average net rates of N mineralization ranged from 0.01 to 0.