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Effect of nitrogen and phosphorus on the water quality in the Three Gorges Reservoir Area during and after its construction

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Journal of Environmental Sciences 2004年第3期16卷 358-363页

作者： LIUHong LIUHui-juan QUJiu-hui StateKeyLaboratoryofEnvironmentalAquaticChemistry ResearchCenterforEco-EnvironmentalSciencesChineseAcademyofSciences.Beijing100085.China

A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO 3 - N, NO 2 - N, Kjeldahl N, non ionic ammonia, P PO 4 and TP) determined at 16 sampling sites from 1997 to 1999 The dominant soluble nitrogen form was NO 3 - N followed by Kjeldahl N, NO 2 - N and non ionic ammonia. Mean values of NO 3 - N, NO 2 - N, Kjeldahl N and non ionic ammonia ranged from 0 50 to 2 37 mg/L, 0 022 to 0 084 mg/L, 0 33 to 0 99 mg/L and 0 007 to 0 092 mg/L respectively. Mean values of P PO 4 at most sampling sites were higher than 0 1 mg/L for subject to eutrophication. The major factors influencing the concentrations of N and P might be agricultural runoff, municipal and industrial effluents. In addition, 6 kinds of soil were sampled at the area where would inundated after the dam completed. Two approaches were adopted to simulate the N and P release from the inundated soils. The results showed that the soils would release nitrogen and phosphorus to the overlying water when the soils were inundated. The characteristics of soil affected the equilibrium concentrations of N and P between the soil and the overlying water.

关键词： Three Gorges Reservoir Area nitrogen phosphorus inundated soil

Releasing nitrogen from ammoniated lignin by white rot fungus cometabolizes environmental pollutants

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Journal of Environmental Sciences 2003年第5期15卷 577-582页

作者： LINLu ZHAODe-qing ZHOUXian-tao QIUYu-gui ZHANGGan: StateKeyLaboratoryofPulpingandPaperEngineering ResearchDivisionofPlantResourceChemistryCollegeofPaperandEnvironmentEngineeringSouthChinaUniversityofTechnologyGuangzhou510640China. StateKeyLaboratoryofOrganicGeochemistry InstituteofGeochemistryChineseAcademyofSciencesGuangzhou510641China

The nitrogen modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH + 4 N was released, NO - 3 N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH + 4 nitrogen flux and bioremediate the polluted environmental sites.

关键词： white rot fungus ammoniated lignin cometabolism pollutants

Soil CO_2 flux in relation to dissolved organic carbon,soil temperature and moisture in a subtropical arable soil of China

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Journal of Environmental Sciences 2003年第5期15卷 715-720页

作者： LOUYun-sheng LIZhong-pei ZHANGTao-lin CollegeofNaturalResourcesandEnvironmentalSciences NanjingAgriculturalUniversityNanjing210095China InstituteofSoilScience ChineseAcademyofSciencesNanjing210008China

Soil CO 2 emission from an arable soil was measured by closed chamber method to quantify year round soil flux and to develop an equation to predict flux using soil temperature, dissolved organic carbon(DOC) and soil moisture content. Soil CO 2 flux, soil temperature, DOC and soil moisture content were determined on selected days during the experiment from August 1999 to July 2000, at the Ecological Station of Red Soil, the Chinese Academy of Sciences, in a subtropical region of China. Soil CO 2 fluxes were generally higher in summer and autumn than in winter and spring, and had a seasonal pattern more similar to soil temperature and DOC than soil moisture. The estimation was 2 23 kgCO 2/(m 2·a) for average annual soil CO 2 flux. Regressed separately, the reasons for soil flux variability were 86 6% from soil temperature, 58 8% from DOC, and 26 3% from soil moisture, respectively. Regressed jointly, a multiple equation was developed by the above three variables that explained approximately 85 2% of the flux variance, however by stepwise regression, soil temperature was the dominant affecting soil flux. Based on the exponential equation developed from soil temperature, the predicted annual flux was 2 49 kgCO 2/(m 2·a), and essentially equal to the measured one. It is suggested the exponential relationship between soil flux and soil temperature could be used for accurately predicting soil CO 2 flux from arable soil in subtropical regions of China.

关键词： soil CO 2 flux soil temperature DOC soil moisture arable soil

HCl emission characteristics and BP neural networks prediction in MSW/coal co-fired fluidized beds

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Journal of Environmental Sciences 2005年第4期17卷 699-704页

作者： CHIYong WENJun-ming ZHANGDong-ping YANJian-hua NIMing-jiang CENKe-fa CleanEnergyandEnvironmentEngineeringKeyLaboratoryofMOE InstituteforThermalPowerEngineeringofZhejiangUniversityHangzhou310027China CleanEnergyandEnvironmentEngineeringKeyLaboratoryofMOE InstituteforThermalPowerEngineeringofZhejiangUniversityHangzhou310027／／SuyuanEnvironmentProtectionEngineeringLtd.Co.Nanjing210024China

The HCl emission characteristics of typical municipal solid waste(MSW) components and their mixtures have been investigated in a Φ150 mm fluidized bed. Some influencing factors of HCl emission in MSW fluidized bed incinerator was found in this study. The HCl emission is increasing with the growth of bed temperature, while it is decreasing with the increment of oxygen concentration at furnace exit. When the weight percentage of auxiliary coal is increased, the conversion rate of Cl to HCl is increasing. The HCl emission is decreased, if the sorbent(CaO) is added during the incineration process. Based on these experimental results, a 14×6×1 three-layer BP neural networks prediction model of HCl emission in MSW/coal co-fired fluidized bed incinerator was built. The numbers of input nodes and hidden nodes were fixed on by canonical correlation analysis technique and dynamic construction method respectively. The prediction results of this model gave good agreement with the experimental results, which indicates that the model has relatively high accuracy and good generalization ability. It was found that BP neural network is an effectual method used to predict the HCl emission of MSW/coal co-fired fluidized bed incinerator.

关键词： municipal solid waste(MSW) HCl emission fluidized bed BP neural networks prediction model

Effects of lignin on nitrification in soil

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Journal of Environmental Sciences 2003年第3期15卷 363-366页

作者： HUANG Yi-zong FENG Zong-wei ZHANG Fu-zhu LIU Shu-qin Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China.

The effects of two lignins isolated from black liquor from pulping process on nitrification in soils after addition of urea, (NH_4)_2SO_4 and (NH_4)_2HPO_4 were investigated by incubation at 20 or 30℃ for 7 or 14 d. The effects of lignin on nitrous oxide emissions from soil were also determined. Results showed that both lignins were more effective for inhibiting nitrification of NH_4 +-N as (NH_4)_2SO_4 or (NH_4)_2HPO_4 as compared to urea-N. The effectiveness of lignin on nitrification was markedly affected by different soil type and temperature. Nitrous oxide emissions from soil declined when lignin was used. Urea plus 20 and 50 g/kg lignin reduced N_2O emissions by about 83% and 96%, respectively, while (NH_4)_2HPO_4 plus 20 and 50 g/kg lignin respectively reduced emissions by 83% and 93%. Because of its low cost and nonhazardous characteristics, lignin has potential value as a fertilizer amendment to improve N fertilizer efficiency.

关键词： lignin nitrification soil N_2O emission

Agroecosystem functional assessment and its difficulties

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Journal of Environmental Sciences 2004年第3期16卷 404-407页

作者： CAOZhi-Ping RichardDawson CollegeofResourcesandEnvironmentalScience ChinaAgriculturalUniversityBeijing100094China DepartmentofUrbanandEnvironmentalScience.PekingUniversity Beijing100871China

Agroecosystem functional assessment indicators provide a necessary bridge between decision makers and scientists. The development of acceptable indicators, however, remains a difficult task because the current knowledge and understanding of ecosystems is not sufficient to allow an objective assessment of all ecosystem functions. These difficulties were summarized from three perspectives. First, there are difficulties in individual function assessment. Of the four functions associated with agroecosystems energy flow, materials cycling, information flow and value flow data on material cycling and information flow remain difficult to obtain and the indicators relatively immature. Secondly, there are difficulties of integration. During the assessment process, the integration of the agroecosystem functions remains the biggest obstacle. Until now, there has been no practical or effective methodology established to resolve the problem. At present, the makeshift approach has been to weight the various indicators and then add them together. Thirdly, there is the problem of obscure concepts and concept confusion. When assessments of agroecosystems are conducted, concepts such as structure, function, benefit, and resource utilization are used extensively. To date, no logical relationship(either real or implied) has been developed between any of these concepts. Are they causes and results such that the relationship between them is linear, or are they independent from one another such that the relationship is parallel? Thus far, the essence of this question is yet to be explored.

关键词： functional assessment indicators agroecosystems ecological benefit

Utility of semivariogram for spatial variation of soil nutrients and the robust analysis of semivariogram

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Journal of Environmental Sciences 2001年第4期13卷 453-458页

作者： Guo, X.-d. Fu, B.-j. Ma, K.-m. Chen, L.-d. Department of Systems Ecology Res. Cntr. Eco-Environmental Sci. Chinese Academy of Sciences Beijing 100085 China

The spatial variation of soil nutrients in topsoil (0-20cm) was analyzed using semivariogram in the Zunhua County of Hebei Province, China. The effect on semivariogram with randomly deleted data and kriged estimates using various reduced sample sizes was also analyzed. The semivariograms of available N, total N, available P, organic matter were best described by a spherical model, except for available K, which best fitted a complex structure of exponential model and linear with sill model. The ratio of nugget to total sample variance ranged from 34.4% to 68.4%, indicating the spatial correlation of tested soil nutrients on a large scale was moderately dependent. Among five soil nutrients, available nitrogen and available phosphorus had the shortest spatial correlation range (5 km and 5.5 km), available K had the longest range (25.5 km), whereas total nitrogen and organic matter had intermediate spatial correlation range (14.5 km and 8.5 km). The semivariograms of available N, total N, available P, and organic matter were insensitive to a 50%-60% reduction in original sampling density, while for available K, it is up to 70%. The estimated spatial distributions of total N by kriging, under various reduced sample sizes, all correlated significantly (P = 0.001) with those obtained from original data. The results showed that the semivariogram was a relatively robust tool when used in a large region and sufficient spatial variation information could be relained regardless of a higher deletion proportion of the original data. The original sample data could be reduced by kriging and the estimates showed no loss of spatial information, however, the results may be unreliable unless a clearly identified semivariogram model could be obtained. The results may provide useful information for determining the appropriate sampling densities for these scales of soil survey.

关键词： Correlation methods Data reduction Nitrogen Phosphorus Sampling Soils Surveying

An investigation of cellular distribution of manganese in hyperaccumlator plant Phytolacca acinosa Roxb. using SRXRF analysis

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Journal of Environmental Sciences 2006年第4期18卷 746-751页

作者： XU Xiang-hua SHI Ji-yan CHEN Ying-xu XUE Sheng-guo WU Bei HUANG Yu-ying Department of Environmental Engineering Zhejiang University Hangzhou 310029 China Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039 China

Phytolacca acinosa Roxb. （P acinosa） is a recently discovered manganese hyperaccumulator plant from southern China. It is a good candidate for phytoremediation of manganese（Mn） polluted soil for its high biomass and fast growth. Knowledge of the tissue localization and identification of heavy metals can provide essential information on metal toxicity and bioaccumulation mechanisms. Synchrotron radiation X-ray fluorescence spectroscopy （SRXRF） microprobe was used in this study to investigate the cellular distributions of Mn and other elements in root, stem, leaf, petiole and midrib of P. acinosa. The highest Mn content was found in the vascular tissues of root, stem, petiole and midrib. Cortex in root played a key role in Mn absorption and Mn was limited in the vascular bundle during the process of transportation in stem. Moreover, Mn content in leaf epidermis was higher than that in mesophyll, which suggested that the sequestration of Mn in leaf epidermis might be one of the detoxification mechanisms of P. acinosa. The significance of other elemental （such as P, S, K, Ca, Fe, Zn and Cu） distribution patterns and the correlation with Mn were also discussed.

关键词： hyperaccumulator Phytolacca acinosa Roxb. manganese element distribution SRXRF

Investigation of protein-styrene oxide adducts as a molecular biomarker of human exposed to styrene

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Journal of Environmental Sciences 2001年第4期13卷 391-397页

作者： Liu, S.-F. Fang, Q.-M. Jin, Z.-L. Rappaport, M.S. Res. Cntr. Eco-Environmental Sci. Chinese Academy of Sciences Beijing 100085 China

Hemoglobin-styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein-styrene oxide adducts in different biological samples with modified Raney-Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro: rat blood reacted with styrene or styrene oxide in vivo: vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose-response relationship between reacting dose of styrene oxide or styrene and amount of protein-styrene oxide adducts in both in vitro and in vivo experiments. For human samples, a dose-response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.

关键词： Blood Drug dosage Glass fibers Hemoglobin Manufacture Oxides Proteins Styrene