Li N.,CAS Research Center for Eco Environmental Sciences |
Li N.,Renmin University of China |
Li N.,Hebei Provincial Academy of Environmental science |
Shan B.-Q.,CAS Research Center for Eco Environmental Sciences |
And 2 more authors.
Huanjing Kexue/Environmental Science | Year: 2011
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, 7.5 and 8.5, organic phosphorus (TOP) accounted for 31.71%-41.73%, 30.85%-43.29% and 27.25%-56.31% of total phosphorus (TP) in the sediments respectively. Alkalescent environment accelerated the process of organic phosphorus mineralization which slowed down when environment was neutral. When temperatures were 15°C, 25°C and 35°C, TOP accounted for 29.07%-46.62%, 27.81%-46.62% and 34.56%-46.62% of TP respectively. The process of organic phosphorus mineralization increased with temperature in the first 10 days but decreased in the following 20 days. Under acidic and high temperature environment, labile organic phosphorus (LOP) has a strong influence on the water quality because of the simultaneous processes of transformations from nonlabile organic phosphorus (NOP) to moderately labile organic phosphorus (MLOP) and from MLOP to LOP.
Yang J.,Ocean University of China |
Yang J.,Hebei Provincial Academy of Environmental science |
Zhang G.,Ocean University of China |
Zhao Y.,Ocean University of China |
Li P.,Ocean University of China
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2011
Nitrification rates, denitrification rates and the sediment-water N 2O fluxs were determined during surveys at the tidal flats of Dagu estuary and Loushan estuary in December 2007, May, September and November 2008 and February 2009. The results showed that the nitrification and denitrification rates in tidal flat sediments had obviously seasonal and spatial variations, with the denitrification rates higher than the nitrification ones. At Dagu estuary, denitrification rates ranged from 9.55 to 104μmol · m -2 · h -1 with maximum values occurring in spring and lowest values occurring in winter due to the influence of temperature and biomass. At Loushan estuary, denitrification rate in summer (215μmol · m -2 · h -1) was higher than that in winter (30.2μmol · m -2 · h -1) due to the influence of organic matter and the concentration of nitrate in the overlying water. Nitrification rates ranged from 0 to 5.11μmol · m -2 · h -1 at Dagu estuary, and from 0 to 0.054μmol · m -2 · h -1 at Loushan estuary. Because of the influence of dissolved oxygen, nitrification hardly happened in summer at both estuaries. The sediment-water N 2O fluxes showed obvious seasonal variations at Dagu and Loushan estuary, which were estimated to be -0.51~4.18μmol · m -2 · h -1 and 0.27~1.68μmol · m -2 · h -1, respectively. On an annual scale, the tidal flat sediments surrounding Jiaozhou Bay was a main source of N 2O in the water column and N 2O mainly came from denitrification.
Jia G.,Hebei University |
Dong D.B.,Hebei University |
Liu J.Y.,Hebei University |
Kang Q.Y.,Hebei Provincial Academy of Environmental science |
Zhang C.M.,Hebei University
Advanced Materials Research | Year: 2014
Uniform and well-dispersed ellipsoidal BaWO4:Dy3+ particles have been prepared via a simple hydrothermal method. The as-obtained particles are non-aggregated with narrow size distribution and are composed of closely packed nanoparticles. During the hydrothermal process, the chelating agent trisodium citrate plays an important role for the formation of BaWO4:Dy3+ hierarchical ellipsoidal particles. The BaWO4:Dy3+ phosphor shows intense yellow emission corresponding to 4F9/2-6H13/2 transition of the Dy3+ ions under ultraviolet light excitation, which may find potential applications in fields of fluorescent lamps, display systems, and optoelectronic devices. © (2014) Trans Tech Publications, Switzerland.
Yang J.,Hebei Provincial Academy of Environmental science
Continental Shelf Research | Year: 2010
The concentrations and sea-to-air fluxes of dissolved methane (CH4) were investigated in the North Yellow Sea during August 2006, January, April and October 2007. Dissolved CH4 concentrations showed obvious seasonal variation, with maximum values occurring in summer and lowest values occurring in winter. The saturations of dissolved CH4 in surface waters ranged from 78.7% to 1679.7% with an average of 252.4%. The estimated atmospheric CH4 fluxes using the Liss and Merlivat (LM86), and Wanninkhof formulae (W92) were (4.2±4.7), (11.6±10.3), (8.5±12.7) and (0.2±1.0), and (6.9±7.3), (14.6±22.3), (13.8±14.3) and (0.4±1.7) μmol·(m2 d)-1, respectively, for spring, summer, autumn and winter. Based on the average annual atmospheric CH4 flux and the area of the North Yellow Sea, the annual CH4 emission was estimated to be (2.4×10-2-4.2×10-2) Tg a-1, which suggests that the North Yellow Sea was a net source of atmospheric CH4. © 2009 Elsevier Ltd. All rights reserved.
Zhou B.,Tianjin University |
Zhou B.,Hebei University of Science and Technology |
Gao Q.,Hebei Provincial Academy of Environmental science |
Wang H.,Hebei Provincial Academy of Environmental science |
And 3 more authors.
Journal of the Air and Waste Management Association | Year: 2012
The oxytetracycline bacterial residue-activated carbon (OBR-AC) prepared from oxytetracycline bacterial residue with K2CO3 under chemical activation was studied. The effects of activation temperature, activation time, and activation ratio on the specific surface area (SSA) and methylene blue adsorption (MBA) were studied. Characterization of the optimum OBR-AC was performed by using scanning electron microscopy (SEM), pore structure (PS,) and Fourier-transform infrared spectroscopy (FT-IR). The optimum parameters were as follows: 800°C activation temperature, 3 hr activation time, and 1:3 activation ratio. The SSA and MBA under optimum conditions were 1593.09 m2/g and 117.0 mg/g, respectively. Adsorption equilibrium and kinetics data were determined for the adsorption of phenol from the synthetically prepared phenol solution. The results showed that the Langmuir model gave the best fit for equilibrium isotherm, whereas the kinetics data were well fitted by the pseudo-second order model.In the past, the bacterial residues have been used for feed additives in China. Unfortunately, doubts of its suitability as a feedstock have been raised because of the small amount of antibiotics, a large number of the fermentation by-products and metabolic products and by-products remaining in the bacterial residues. So Oxytetracycline Bacterial Residue (OBR) is one of hazardous wastes in China. In order to solve the problem of OBR, the preparation of OBR-AC is studied, and OBR-AC under optimum operation parameters is characterized by Scanning Eldctron Microscopy (SEM), Pore Structure (PS) and Fourier Transfer-Infra Red (FT-IR). Moreover, the phenol adsorption isotherms and kinetics models for OBR-AC under optimum operation parameters are studied. © 2012 Copyright 2012 A& WMA.