[Decomposition of and the Associated Release of Nitrogen and Phosphorus].

Decomposition of wetland plants could release pollutants, which may affect the removal efficiency and effluent quality of constructed wetlands. The experimental decomposition test of was carried out for 60 d using nylon bags, and release characteristics of nitrogen and phosphorus during the decomposition process were studied. The results showed that the decomposition rate of was fastest during the first 0-4 d, with a weight loss of 30%, while the degradation rate slowed gradually during the period 4-60 d, with weight loss of 31%.

[Removal Performance and Mechanism for Treating Phosphorus in Agricultural Wastewater by Three Adsorbents].

To screen the optimal absorbents for P removal from agricultural wastewater, the P adsorption capacity of bentonite, red soil, and slag was studied using synthetic wastewater. Combing the properties of three adsorbents measured by SEM, XDS, and BET methods, the isothermal adsorption, adsorption kinetics, and Ca release capacity were analyzed to elucidate the mechanisms of P adsorption. The results showed that the P adsorption capacity of slag was higher than that of bentonite and red soil, and the Langmuir isotherm model was able to better fit the adsorption data (>0.

[Photosynthetic mechanism of tea yield and quality affected by different habitats].

To understand photosynthetic mechanism of tea yield and quality, an experiment was conducted with four different typical habitats, including three intercropping patterns (S:Osmanthus-Tea, S:Michelia-Tea, S:Osmanthus-Michelia-Tea) and a control (CK) at Changsha Agricutural Observation Station of Chinese Academy of Sciences. The photosynthetic physiological and ecological characteristics of tea yield and quality were examined. The results showed that the habitats S, S, S reduced the leaf temperature (TL), photosynthesis active radiation flux (PAR), net photosynthetic rate (P), transpiration rate (T), and stomatal conductance (g), as well as the tea polyphenol content.

[Comparison Between Atmospheric Wet-only and Bulk Nitrogen Depositions at Two Sites in Subtropical China].

Atmospheric emissions of reactive nitrogen (N) species are at high levels and have caused high N deposition in China in recent years. In this study, atmospheric wet-only and bulk N depositions were monitored simultaneously in a two-year study at an agricultural site (HN) and a forest site (XS) in the Jinjing River catchment in Changsha County, Hunan Province in subtropical China. The differences in concentration and deposition of NH-N, NO-N, DON, and TN between wet-only and bulk N depositions were compared, and the correlation between wet-only and bulk N depositions was analyzed, with the aim of estimating atmospheric wet N deposition based on bulk N deposition.

[Physiological Characteristics and Nitrogen and Phosphorus Uptake of Under High Ammonium Conditions].

Ammonium nitrogen (NH-N) at high concentrations is toxic to plants. In order to explore the NH-N tolerance of () and its ability of nitrogen (N) and phosphorus (P) uptake, this study used a nutrient solution with three NH-N levels (70, 210, 420 mg·L) to incubate for 21 d. The characteristics of plant physiology and N and P uptake of were measured.

Anaerobic ammonium oxidation in sediments of surface flow constructed wetlands treating swine wastewater.

Anaerobic ammonium oxidation (anammox) was suggested to be involved in the nitrogen (N) removal process in constructed wetlands (CWs). Nevertheless, its occurrence and role in CWs treating swine wastewater have not been well evaluated yet. In this study, we investigated the diversity, activity, and role of anammox bacteria in sediments of mesoscale surface flow CWs (SFCWs) subjected to different N loads of swine wastewater.

[Interception Effect of Vegetated Drainage Ditch on Nitrogen and Phosphorus from Drainage Ditches].

In order to effectively intercept and remove nitrogen (N) and phosphorus (P) from agricultural water, Canna glauca, Sparganium stoloniferum, Juncus effusus, Hydrocotyle vulgaris, and Myriophyllum elatinoides were planted in an agricultural drainage ditch. The temporal and spatial variations of the dissolved N and P concentrations were monitored during the whole experimental period. In addition, the contents of N and P in sediments and plants were compared among different plant plots.

[Study on phosphorus adsorption characteristic of sediments in an ecological ditch].

Sediments properties and phosphorus (P) adsorption capacities were compared among the samples of 0-5 cm and 5-15 cm layers from the ecological ditch vegetated with Cenetlla asiatica, Sparganium stoloniferum and a natural agricultural ditch with weeds. The results showed the 0-5 cm sediment vegetated with Cenetlla asiatica had higher concentrations of oxalate extracted Fe, Al and P than those vegetated with Sparganium stoloniferum or weeds. The parameters calculated from the Freudlich and Langmiur isotherms showed the equilibrium phosphate concentration (EPC0) ranged from 0.