Water quality criteria and ecological risk assessment for ammonia in the Shaying River Basin, China.

Current Chinese surface water environmental quality standard GB3838-2002 for ammonia fails to take water quality factors and native organism distributions in different basins into consideration. In this study, ammonia toxicity tests were performed using three aquatic organisms native to the Shaying River Basin (China). Published ammonia toxicity data with pH and temperature, and toxicity data acquired in this study were used to establish water quality criteria.

[Sources and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Jiaxing River Network].

In order to study the pollution source and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the Jiaxing river network, PAHs were analyzed by GC-MS. The results show that with the influence of rainfall and surface runoff in the wet season, the types and mass concentrations of PAHs in the river network of Jiaxing differ from the dry season. Ten and 16 priority PAHs were detected in the dry season and wet season, respectively.

Deriving water quality criteria for China for the organophosphorus pesticides dichlorvos and malathion.

Organophosphorus pesticides are effective, cheap, and used extensively but can harm aquatic organism and human health. Here, water quality criteria (WQCs) for dichlorvos (DDVP) and malathion (MAL) were derived. Nine aquatic organisms native to China were used in toxicity tests.

Fluorescent characteristic and compositional change of dissolved organic matter and its effect on heavy metal distribution in composting leachates.

Composting leachates were collected to investigate the fluorescent characteristic and compositional change of dissolved organic matter (DOM) and the effects of the DOM and nutrients on heavy metal distribution during a leachate combination treatment process. Excitation-emission matrix (EEM) fluorescence spectra showed that, with the progress of the treatment units, the content of fulvic-like, humic-like, and protein-like substances gradually decreased. One fulvic-like component (C1), three humic-like components (C2, C3, and C4), and three protein-like components (C5, C6, and C7) were identified in the leachate DOM by parallel factor analysis.

Effects of algal bloom formation, outbreak, and extinction on heavy metal fractionation in the surficial sediments of Chaohu Lake.

The effects of algal bloom (AB) on the physicochemical and biochemical properties of water and sediment in lakes have been widely studied. However, limited attention has been directed toward the effects of the processes of AB formation, outbreak, and extinction on heavy metal fractionation in sediment. In this study, water and sediment samples were collected from the AB and free algal bloom (FAB) regions of Chaohu Lake from May to September in 2012.

Detection of Copper (II) and Cadmium (II) binding to dissolved organic matter from macrophyte decomposition by fluorescence excitation-emission matrix spectra combined with parallel factor analysis.

Fluorescence excitation-emission matrix (EEM) spectra coupled with parallel factor analysis (PARAFAC) was used to characterize dissolved organic matter (DOM) derived from macrophyte decomposition, and to study its complexation with Cu (II) and Cd (II). Both the protein-like and the humic-like components showed a marked quenching effect by Cu (II). Negligible quenching effects were found for Cd (II) by components 1, 5 and 6.

[Allelopathic effect of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda].

Effects of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda were studied to verify its potential in entriphication control. Five concentrations of Nelumbo nucifera stem and leaf tissue extract were chosen to compare their inhibitory effects on the growth of Microcystis aeruginosa and Scenedesmus quadricanda. The result showed that the leaf extract inhibited the algae bloom more effectively than the stem extract on the whole.

[Canonical correspondence analysis between phytoplankton community and environmental factors in macrophtic lakes of the middle and lower reaches of Yangtze River].

The phytoplankton communities in 4 macrophtic lakes (Longgan Lake, Liangzi Lake, Futou Lake and Baoan Lake) in Middle-Lower Yangtze Plain were investigated in September 2011, and 7 phylum and 231 species of phytoplankton were detected in the waters. The results indicated that phytoplankton was mainly composed of Cyanophyta, Bacillariophyta and Chlorophyta. The four lakes were mesotrophic.

[Strategies of nutrients control in lakes based on ecoregions of lakes in China].

In order to better reduce lake eutrophication, based on five ecoregions of lakes, the relationships of total nitrogen (TN), total phosphorus (TP), and TN/TP ratio with chlorophyll-a (Chl-a) in 100 lakes were discussed, furthermore, strategies of nutrient control were proposed respectively. Results showed that among the five ecoregions, the lake eutrophication level was the lowest in Dongbei ecoregion and the highest in Huabei ecoregion, but the eutrophication level in lakes of all the five ecoregions is increasing in recent years. Algal growth in lakes of Dongbei and Huabei ecoregions was limited by phosphorus, while it was simultaneously limited by nitogen and phosphorus in lakes of other three ecoregions (Zhongdongbu, Yungui and Mengxin).

[Speciation and vertical distribution of heavy metals in sediments of Baiyangdian Lake].

In order to find out the heavy metal concentrations and their potential ecological risks on sediments in Baiyangdian Lake, 0-14 cm surface sediments had been collected by the no-disturbance-gravity sampler at seven representative sampling points of Baiyangdian Lake. Optimized BCR sequential extraction procedure was used to carry out the analysis of heavy metal forms in the surface sediments. The heavy metal contents of different forms and in different depths were determined.

[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.

[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.

[Phosphate transform of composting with pre-mixing insoluble phosphate using high temperature dissolved phosphorus microbes inoculation].

In order to enhance the available phosphorus (P) of compost production, the experimental design of composting included three treatments was conducted. The treatments were: Control (CK) with no dissolved phosphate microbes inoculation, no rock phosphate mixing; CP with no dissolved phosphate microbes inoculation, rock phosphate mixing; CMP with dissolved phosphate microbes inoculation, rock phosphate mixing. At different composting phases, the samples were taken for the determination of phosphorus forms.

[Effect of using three stages inoculation controlled by temperature on organic matter transformation during composting process].

In order to accelerate composting efficiency, municipal solid wastes (MSW) composting was conducted using three stages inoculation controlled by temperature (TSCT). At different composting phases, the samples were taken for the determination of organic matter transformation. Compared to routine inoculation method (CK), total organic carbon (TOC), dissolved organic matter (DOM) of TSCT decrease by 6.

Effects of effluent recirculation in vertical-flow constructed wetland on treatment efficiency of livestock wastewater.

Enhancing the treatment efficiency of livestock wastewater by effluent recirculation is investigated in a pilot-scale vertical-flow constructed wetland. The wetland system is composed of downflow and upflow stages, on which narrow-leaf Phragmites communis and common reed Phragmites typhia are planted, respectively; each stage has a dimension of 4 m(2) (2 m x 2 m). Wastewater from the facultative pond is fed into the system intermittently at a flow rate of 0.

[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.

[Phosphorus characteristics in leachate from soils irrigated with livestock wastewater].

Phosphorus fractions could enter water body from surface runoff and leachate due to excessive irrigation of centralized farm wastewater. Organic P is more mobile than inorganic P in the soil profile and represents a significant proportion of P present in leachate from irrigated farm soils. A set of parallel experiments were conducted to compare the characteristics of organic phosphorus in leachate.