Liaohe Basin Research Articles

Identification and distribution of pyrene, methylpyrenes and their isomers in rock extracts and crude oils

Pyrene (Py), its alkylated homologues, fluoranthene (Fla), benzo[a]fluorene (BaF) and benzo[b]fluorene (BbF) have been unequivocally identified in crude oils and sedimentary rocks by co-injection with authentic standards and comparison of retention indices with those reported in the literature. The distribution patterns of pyrene, its C1–C2 alkyl derivatives and their isomers were then investigated in oils and sedimentary rocks with Early Paleozoic and Cenozoic origins. The oil groups of Ordovician–Cambrian reservoirs in the cratonic region of the Tarim Basin (NW China) are distinguished on the basis of the distribution patterns of pyrene, fluoranthene and their methylated homologues. The majority of the oil accumulations are characterized by low concentrations of fluoranthene and methylfluoranthenes relative to pyrene and methylpyrenes, respectively. In contrast, oils from wells TD2, TZ26, TZ162 and TZ451 have relatively higher concentrations of fluoranthene and methylfluoranthenes, indicating different origins. The distribution patterns of methylpyrenes in Cenozoic lacustrine shales from the Liaohe Basin (East China) show effects of maturity, where the 2-/1-MPy and MPYR (2-MPy/(2-MPy+1-MPy)) ratios display a regular increase with increasing maturity. This study shows that pyrene, its alkylated homologues and their isomers are useful molecular markers in petroleum geochemistry and that the 2-/1-MPy and MPYR ratios are potential maturity indicators.

The Temporal and Spatial Vegetation Variation of Liaohe Basin and its Relation with Climate Changes

In this paper, 2000-2010 NDVI data of Liaohe Basin is obtained with the RS technology; the distribution map of precipitation and air temperature in Liaohe Basin is generated by the GIS technology, and then the temporal and spatial vegetation variation of Liaohe Basin and its relation with climate changes have been studied by means of raster data spatial analysis, correlation analysis and multiple regression analysis, so as to provide a scientific basis for ecological environment protection, planning and development of Liaohe Basin. It is shown from results that: 1) From 2000 to 2010, the vegetation coverage increased significantly; which presents a gradual decrease from east to west on the spatial distribution; 2) For the temporal distribution, the precipitation presents a fluctuant upward trend; while temperature is fluctuated significantly with a slight decrease. For the spatial distribution, precipitation decreased gradually from the east to west, while temperature rises from the northeast to southwest; and 3) Vegetation coverage of Liaohe Basin is positively related with precipitation and temperature in the temporal and spatial distribution, but not significantly, it is indicated that, except for the meteorological factors, the artificial impact and other factors, such as land use, played an important role to vegetation variation of Liaohe Basin in the recent 10 years. However in terms of two influence factors of precipitation and temperature, the former has significantly contributed to NDVI change of Liaohe Basin.

Biodegradation of 25-norhopanes in a Liaohe Basin (NE China) oil reservoir

A suite of reservoir cores in an oil column from the Shuguang oil field, Liaohe Basin, NE China was characterized geochemically to investigate the behaviour of 25-norhopanes (NHs) during biodegradation. The extracted bitumens show similar organofacies type and maturity levels with biodegradation as the primary control on compositional variation. All bitumens suffered severe biodegradation influence which removed all regular steranes and most of the pentacyclic terpanes leaving NHs as dominant components in total ion chromatograms of the saturated hydrocarbon fraction. However, the NHs are not the endpoint of hopane destruction: they are biodegraded as well. Biodegradation of NHs can be illustrated by significant depletion in their concentrations and systematic variation in ratios of resistant to vulnerable components throughout the oil column. The biodegradation sequence is somewhat similar to normal pentacyclic terpanes. Among the NH series, 18α-25,30-bisnorneohopane is the most recalcitrant to biodegradation. The 18α-22,25,29,30-tetranorneohopane is more resistant to biodegradation than 17α-22,25,29,30-tetranorhopane and 34NHs are more resistant than other NHs. Degradation of NHs provides a new angle to understanding the complicated inter-relationships in subsurface biodegraded reservoirs.

Viscosity Prediction of Heavy Oil from the Liaohe Basin Using Biomarker Parameters

A set of correlations was proposed to predict the viscosities of heavy oils from Leng 43/37 blocks (Liaohe Basin) using some biomarker parameters. Geochemical analysis showed that the heavy oils in this study main suffered from different degrees of biodegradation. With increasing biodegradation, the viscosities of crude oils have strong correlations with the following four biomarker biodegradation parameters: (Pr + Ph)/(nC17 + nC18), (nC17 + nC18)/C30H, nC17 + nC18 + Pr + Ph (mg/g), ∑(nC11 − nC36) (mg/g); the correlation coefficients were 0.96, 0.94, 0.93, and 0.94, respectively. Moreover, for convenience, we ranked the extent of biodegradation as nonbiodegraded and lightly, moderately, heavily, and severely biodegraded. The accuracy and applicable biodegradation scale range of these correlations are discussed. The viscosities obtained from the correlations could be used in designing biodegraded heavy oil production projects.

Secondary microbial gas formation associated with biodegraded oils from the Liaohe Basin, NE China

A suite of oils and associated gases from the Liaohe Basin NE China, which have similar maturity and source rock origin but with varying degrees of biodegradation, have been analyzed for the molecular compositions of oil and gas as well as for the isotopic values. Isotopic compositions of the gas samples show wide variation (δ13C1 from −55.4‰ to −36.8‰, δ13C2 from −39.4‰ to −28.5‰, δ13C3 from −31.9‰ to −16.4‰ and δ13n-C4 from −26.6‰ to −20.4‰). Most gas samples display clear geochemical evidence of alteration by biodegradation, with relatively high dryness (C1/C1–4>0.97), high ratios of isobutane/n-butane (0.4–1.8) and C2/C3 (0.3–42.3). The carbon isotopic compositions of wet gas components (C3 and C4) in the biodegraded gases are heavier than these in non-biodegraded gases with Δδ13C (C3−C2) of up to 13.4‰, but methane and ethane isotope signatures are variably heavier or lighter than those in non-biodegraded gases. Carbon dioxide contents and isotopic values provide evidence for gas origins. Gases with isotopically heavy carbon dioxide (δ13C>+2‰), and isotopically light methane (δ13C<−50‰) indicate that secondary microbial methane was generated from CO2 reduction under anaerobic conditions. Gases with isotopically heavy methane (>−45‰), together with heavy carbon dioxide (>+8‰), probably indicate a high degree of CO2 conversion to methane under later stages of secondary microbial methane generation. We speculate that the presence of isotopically heavy methane (>−45‰) and isotopically light carbon dioxide (<−8‰) may be indicative of anaerobic methane oxidation but much additional work is needed to evaluate that.It seems likely that most of the variations in isotopic signatures of gases related to biodegraded oil can be described by various sequential biodegradation, carbon dioxide reduction and gas mixing processes. Methanogenesis through carbon dioxide reduction does not necessarily produce isotopically depleted methane. The methane becomes richer in 13C when a large fraction of carbon dioxide is reduced to methane, resulting in newly generated methane that is sometimes heavier than the original thermogenic methane. Anaerobic methane oxidation may exist in the present case study. Mixing of newly generated methane with thermogenic methane already in place in the reservoir, coupled with anaerobic methane oxidation, can result in very complicated isotopic signatures. Care should be taken when gas isotopic values were applied for source and maturity assessment.

The distribution and origin of dimethyldibenzothiophenes in sediment extracts from the Liaohe Basin, East China

The distributions of dimethyldibenzothiophenes (DMDBTs), the relationship between DMDBTs and dimethylbiphenyls (DMBPs), and the applications of DMDBTs as maturity indicators in source rocks have been investigated in a set of 21 lacustrine shales from the Eocene Shahejie Formation (Well SG1) in the Western Depression, Liaohe Basin, China. All source rock samples are characterized by total organic carbon contents of 1.37–3.27% and Type II (with minor Type III) kerogen. They were deposited in suboxic and brackish lacustrine environments and have maturities ranging from immature to mid-mature. The 3,3′-DMBP isomer can potentially react to yield 4,6-DMDBT; 2,6-DMDBT and 2,8-DMDBT by incorporating sulfur into biphenyl, which may be supported by a strong positive correlation between the absolute concentration changes of 3,3′-DMBP and those of 4,6-DMDBT, 2,6-DMDBT plus 2,8-DMDBT. The relative abundance of DMDBT isomers may be explained by the sulfur radical mechanism and are also controlled by steric hindrance and thermodynamic stability. The 4,6-/(1,4-+1,6)-DMDBT ratio shows no regular trend with increasing maturity at the low stage, and it should be used with caution as a maturity indicator for immature sediments. However, within the oil generation window, the relative concentration of 4,6-DMDBT progressively increases with increasing maturity, which can be explained by its higher thermodynamic stability relative to the 1,4-DMDBT isomer. The 4,6-/(1,4-+1,6)-DMDBT ratio exhibits a linear increase with increasing thermal maturity of the sediments. Thus, this ratio can be applied as an effective maturity indicator for source rocks within oil generation window.

Multi-scale analysis of the water resources carrying capacity of the Liaohe Basin based on ecological footprints

A multi-scale assessment framework for evaluating water resource sustainability based on the ecological pressure index (EPI) is introduced. The study aims to correct the following flaws in the WEF: the difference between assessment and reality resulting from the fluidity of water resources; the lack of management and planning as a part of the dynamic tendency in the traditional water resource ecological footprint (WEF). The multi-scale EPI comprises the ratio of the WEF to water resource ecological carrying capacity (WECC) after comparing the traditional ecological footprint and the water footprint for correcting the former fault. Results show that the gap between the assessment and reality is more obvious from upstream to downstream. Such gap is demonstrated through the large differences in the EPI values of Panjin in 2002, with 13.87 in the city scale, 1.82 in the watershed scale involving the fluidity of the water resource among the cites, and 1.70 in the basin scale. The mean EPI values of the Liao-Hun and Taizi Watersheds are 1.36 and 1.17, respectively, indicating the imbalance of water resource supply and consumption between the watersheds. By forecasting the population, we determined that the time series prediction of EPI in the basin for the second flaws will exceed 1.33 in 2025, indicating that the water resource sustainability may be insufficient in the future. The proposed multi-scale assessment of WEF aims to evaluate the complex relationship between water resource supply and consumption in different spatial scales and time series. It also provides a more reasonable assessment result that can be used by managers and regulators.

Analysis of Chaotic Characters for the Monthly Runoff Se-ries at Fudedian Station in Liaohe Bain

The evolution of monthly runoff is affected both by climate environment and human activities, and its characteristics play an important role in runoff prediction and simulation. In this paper, the G-P and the principal component analysis method, which are both based on the reconstruction theory of the phase space, are used to study the chaos characteristics of the monthly runoff series at Fudedian station in Liaohe basin. The results show that the monthly runoff series have a large probability of chaos.

Revision of the loach species Barbatula nuda (Bleeker 1865) (Pisces: Balitoridae) from North China, with a description of a new species from Inner Mongolia

Variation in the currently recognized species, Barbatula nuda (Bleeker 1865), from North China was studied, and threedistinct species are identified: B. nuda, B. toni, and B. gibba sp. nov.. The name B. nuda is presently misapplied; this speciesis distinct from B. toni, a species widely distributed in Northeast China, and occurs only in the Liao-He basin of LiaoningProvince and the Tumen-Jiang basin of Jilin Province. The new species, B. gibba, is only found in Dali-Nur Lake in Inner Mongolia. Among Chinese Barbatula species, it is uniquely distinguished by the shape of the predorsal body.

Comprehensive Evaluation and Prediction of Geothermal Resources in Liaohe Basin

Geothermal resources can not be ignored in the new century energy, Through the relevant formula in combination with the actual situation of the Liaohe Basin, by the predication of single well production and well head temperature, Find favorable areas that single well production and wellhead temperature both high. These areas are considered favorable areas for geothermal resources in Liaohe Basin. We carry out comprehensive evaluation of geothermal resources in Liaohe Basin. Finally, the total amount of geothermal resources, the total amount of geothermal water and recoverable geothermal resources in Liaohe Basin were determined and the favorable area for geothermal resources is divided, the total amount of geothermal resources, the total amount of geothermal water and recoverable geothermal resources the favorable area for geothermal resources were predicted.These results provide guarantee for the future exploration and development of geothermal resources.

The Cognition Decide the Exploration- The Exploration Study on Buried Hill Reservoir in the Liaohe Basin

In recent years the buried hill exploration was a main power for increasing reserve&amp; production in the Liaohe oil field. By the research and analysis on the buried hill reservoir exploration in the Liaohe oil field in the paper, It point out that the previously mistake cognition was broken through in the buried hill reservoir exploration with the seismic, logging etc. technology development. The achievement list as: 1. The conclusion is drawn about the depth of the buried hill reservoir determined by the depth of the source rock which clarified the mistake about the buried hill reservoir formed only in the shallow formation. 2. The inner of the buried hill reservoir of the metamorphic rock is a fissure-cave system formed by the various and layered rocks which served as an oil accumulation place which broke through the cognition on no pore in the deep inner of the buried hill reservoir. 3.The reservoir-formed pattern is built on the study of the controlled factor in the buried hill reservoir which denied the barrier of the basalt layer for oil and gas translation over the buried hill reservoir .In this paper by the summary of the cognition breakthrough and achievement, it shows the next exploration direction in buried hill reservoir in the Liaohe depression.

The origin of trimethyldibenzothiophenes and their application as maturity indicators in sediments from the Liaohe Basin, East China

The distributions of trimethyldibenzothiophenes (TMDBTs), the relationship between TMDBTs and trimethylbiphenyls (TMBPs) and the application of TMDBTs as maturity indicators have been investigated in a set of lacustrine shales from the Eocene Shahejie Formation in the Liaohe Basin, East China. The 3,5,3′-, 3,5,4′- and 3,4,4′-TMBP isomers can react to yield (2,4,6-+2,4,8)-TMDBT, 2,4,7-TMDBT, and (3,4,7+2,3,7)-TMDBT by incorporating a sulfur atom into biphenyl, respectively. The absolute concentrations of (2,4,6+2,4,7+2,4,8)-TMDBT increase with those of (3,5,3′+3,5,4′)-TMBP. Similarly, the absolute concentrations of (3,4,7-+2,3,7)-TMDBT show a similar increase with those of 3,4,4′-TMBP. The good straight line relationships (R2=0.96) indicate the product–precursor links between TMDBTs and TMBPs in the sediments. On the basis of the possible differences in the thermodynamic stability among TMDBT isomers, a new maturity indicator 2,4,6-/(2,4,7+2,4,8)-TMDBT ratio is proposed in this study. This ratio has a good correlation with 4-/1-methyldibenzothiophen ratio (MDR) and Tmax (°C), respectively, indicating similar behavior with increasing maturity. Both of the 2,4,6-/(2,4,7+2,4,8)-TMDBT ratio and MDR exhibit similar maturation trends. They gradually decrease with increasing maturity at the low maturity stages, and then are followed by a regular increase with the increasing maturity. Therefore, this ratio is an effective maturity indicator for source rocks and an oils maturity assessment (Ro>≈0.55%), and it must be applied with caution as a maturity indicator for extracts of immature sediments.

Analysis of Water Resources Carrying Capacity in Liao River Basin

In order to discuss the water resources carrying capacity in Liaohe river basin, which is defined as the ultimate water resources carrying capacity, this paper mainly calculated the water resources threshold based on the lower and upper available water resources according to the minimum and appropriate ecological water requirement. Bring forth water resources carrying capacity threshold theoretical system, multi-objective algorithm is used to calculate the ultimate water resources carrying capacity for three different social and economic development projects, such as ‘ecological maintenance’, ‘ecological soundness’ and ‘ecological soundness with water saving’, and analyzed the calculation result with the characteristics of each city. The results showed that the water resources in Yingkou and Panjin have been overtaken, that in Shenyang and Anshan are over lifted to some extent and water resources in other cities still have some space to extract. Meanwhile, the ecological social and economic benefit of the third project is the best compared with the other two.

The occurrence and distribution of phenylphenanthrenes, phenylanthracenes and binaphthyls in Palaeozoic to Cenozoic shales from China

The distributions of phenylphenanthrenes, phenylanthracenes and binaphthyls in sediment extracts have been investigated in a set of lacustrine shales from the Eocene Shahejie Formation (well SG 1) in the western Depression of Liaohe Basin, East China. All isomers of these phenyl substituted polycyclic aromatic hydrocarbons (PAHs) have been identified in the m/z 254 mass chromatograms by comparison of the mass spectra and standard retention indices with those published elsewhere. The 2,2′-binaphtyl/1,2′-binaphthyl ratio values show a linear increase with increasing maturity, and have a good correlation with Tmax (°C). Therefore, they can be used as an effective maturity indictor for source rocks in this study. In the main phase of the oil generation window, the 3-phenylphenanthrene and 2-phenylphenanthrene prevail over other isomers, and some thermodynamically unstable isomers including all phenylanthracenes, 4-phenylphenanthrene and 1,1′-binaphthyl are present at very low concentrations or below the detection limit in the m/z 254 mass chromatograms. The absolute concentrations of individual phenylphenanthrene and binaphthyl isomers were obtained by comparison of the peak areas with that of internal standard phenanthrene-d10. All isomers are present at low concentrations at low maturity stages and then show an abrupt increase at a depth of ≈3100 m, corresponding to the onset of the intensive C15+ hydrocarbon generation. The Phenylphenanthrene Ratio (2- + 3-PhP)/[(2- + 3-PhP) + (4- + 1- + 9-PhP)] shows a reverse change with increasing maturity at the low maturity stage. It displays a drastic increase at a depth of ≈3100 m and then remains at a nearly constant value. This study can expand the understanding of the formation and distribution of phenyl substituted PAHs in sedimentary organic matter deposited in various environments.

Identification and distribution of chrysene, methylchrysenes and their isomers in crude oils and rock extracts

Chrysene, its methylated homologues and their structural isomers are important polyaromatic compounds in crudes oils, coals and sediment extracts. Chrysene, benzo[a]anthracene, methylchrysenes and methylbenzo[a]anthracenes were unequivocally identified in mass chromatograms by comparison with authentic standards and by retention indices reported in the literature. The response factors relating those of chrysene and methylchrysenes to internal standards [perdeuterated chrysene (chrysene-d12) and pyrene (pyrene-d10)] were obtained by GC–MS analyses of mixture solutions with different concentration ratios. The oil families of Ordovician reservoirs in the cratonic region of the Tarim Basin (NW China) are distinguished by the distribution patterns of chrysene, methylchrysenes and their isomers. The majority of the oil accumulations and sediment extracts from the Middle–Upper Ordovician source rocks are characterized by low concentrations of benzo[a]anthracene and methylbenzo[a]anthracenes relative to chrysene and methylchrysenes, respectively. In contrast, some oils with relatively high abundances of benzo[a]anthracene and methylbenzo[a]anthracenes were derived from Cambrian and Lower Ordovician source rocks. The effect of maturity on the distribution patterns of methylchrysenes in Tertiary lacustrine shales from the Liaohe Basin (East China) was investigated. The 2-/1-methylchrysene ratio keeps a nearly constant value with increasing maturity at the low maturity stages and then it abruptly increases, corresponding approximately to the onset of intense C15+ hydrocarbon generation. This indicates that chrysene and its methylated homologues are useful molecular indicators in petroleum geochemistry.

Distribution of acids and nitrogen-containing compounds in biodegraded oils of the Liaohe Basin by negative ion ESI FT-ICR MS

Seven reservoir core (tar sand) bitumens of identical source and similar maturity from the Liaohe Basin of northeast China possess a natural sequence of increasing severity of biodegradation. This set of samples provides us an opportunity to study the change in oil composition or compound class distributions with biodegradation severity by negative ion electrospray Fourier transform-ion cyclotron resonance mass spectrometry (FT ICR-MS). The bitumen extracts from two columns (Es3 and Es1) were separated into maltene and asphaltene fractions for analysis of heteroatomic species by ESI FT-ICR MS. The maltene fractions were found to mainly contain N1, N1O1, N1O2, N1O3, O1, O2, O3 and O4 classes, while the asphaltene fractions mainly contain N1, N2O1, N1O1, N1O2, N1O3, N1O4, O2, O3, O4 and O5 classes. These species identified by FT-ICR MS in asphaltene fractions are likely to be chemisorbed/coprecipitated compounds, or the species precipitated due to high polarity during deasphaltene process. The susceptibility of compound classes and homologous series to biodegradation was studied based on the relative abundances. The results indicate that microorganisms alter the distribution of acids and nitrogen-containing compounds by selective removal and preservation of certain classes of compounds according to their susceptibility to biodegradation. For example, O2 and N1O2 classes increase significantly while N1 and N1O1 classes decrease with biodegradation. The differences in the susceptibility to microbial alteration within acyclic acids, 4–5 ring acids and 1–2 ring acids are discussed and the differences in the susceptibility of homologous series of heteroatom-containing polycyclic aromatic hydrocarbons are also discussed in this work.

Estimation of Daily Actual Evapotranspiration from ETM+ and MODIS Data of the Headwaters of the West Liaohe Basin in the Semiarid Regions of China

AbstractEvapotranspiration (ET) is an important, but unmeasurable, component of the hydrological cycle in semiarid regions. Traditionally, actual ET is computed as residual in water balance equations. It is derived from estimates of potential ET or, indirectly, from field measurements at meteorological stations. Recently, researchers have begun using scintillometers, remote sensing data, and hydrological models to estimate areal actual ET. In this study, the surface energy balance algorithm for land (SEBAL) was used to derive ET maps from moderate resolution imaging spectroradiometer (MODIS) images over the Laohahe basin and Shalamulun River basin. The effect of ground parameters on ET of the study area was quantified using the spatial analysis techniques of ArcGIS. At the end, ET estimated from Landsat 7 enhanced thematic mapper plus (ETM+) was compared with that from MODIS data over the Shalamulun River basin. SEBAL is a suitable algorithm for mapping evaporation over semiarid areas, using MODIS and Lan...

Geochemistry of source rocks in the Es3 and Es4 members in the Shahejie Formation of the Western Depression, Liaohe Oilfield, China

The Western Depression of the Liaohe Basin is the major exploration area of the Liaohe Oilfield, and its main source rocks consist of the third and fourth members of the Shahejie Formation (Es3 and Es4). These source rocks are widely distributed in the depression, with semi-deep lake and fan delta as the main sedimentary facies, brown oil shale and black gray-dark gray mudstone as the main rocks, and a total thickness of 270–1450 m. The kerogens are mainly of the types I and IIA, and partly of the type IIB and least of the type III. The Ro values range from 0.4%–0.8%, indicating an evolution stage from immature to mature. The maturity of Es4 source rocks is relatively high, reaching the early mature stage, but their distribution and thickness are lower than those of Es3. Besides, according to biomarker analysis, it is thought that the source rocks of Es3 and Es4 are characterized by mixed input, and most of the source rocks were formed in the brackish water-saline and strongly oxygen-free environment. Furthermore, the Qingshui, Niuxintuo and Chenjia sags are believed to possess greater potential for hydrocarbon generation and expulsion, for they are source rocks with a larger thickness, have higher organic carbon contents, belong to better organic matter types and possess higher maturities.

An rescaled range analysis on the characteristics of coal seam development in the Eastern depression of the Liaohe Basin

The characteristics of coal seam development, and the prospects of a favorable coal-forming area, were evaluated for the Liaohe Basin located in China. The Number 3 and Number 9 coal seam thickness series from 60 nearly equally spaced bores in the Eastern depression of the Liaohe Basin were examined by a rescaled range analysis. The results indicate that the Hurst exponents of the Number 3 and Number 9 coal seam thickness series are 0.69 and 0.68, respectively. This suggests the presence of persistence. As the bore spacing increases the Hurst exponent of the Number 3 series gradually decreases ( H changes from 0.69 to 0.52) and shifts from persistence to randomness. The Hurst exponent of the Number 9 thickness data gradually increases ( H changes from 0.68 to 0.91) and always shows the characteristic of persistence. A combination of geological characteristics and the series data allow the conclusion that it is more suitable for the Number 9 coal seam to form in the Northeastern part of the Eastern depression than the Number 3 coal seam.

Adsorption characteristics of 3-nitrogen absorbed by the soil-plants in Xiquan lake wetland

Abstract In allusion to water pollution of the Xiquan Lake wetland in Liaohe river basin, the three nitrogen adsorption rules were studied through the adsorption experiments of soil-plants over 3-nitrogen in Xiquan lake. The goal to protect the safety of the Xiquan lake reserve groundwater sources was attained. The native soil and the aboriginal plants named Typha orientalis Presls were used through the study and the contamination adsorption rules of the soil-plants system were analyzed and summed up through testing the removal rate of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen by the soil-plants. The average adsorption and degradation coefficient of the growing period and non-growing period were calculated by the first order reaction ratio equation. The research obtained that it was an adsorption capacity that the soil-plants absorbed contaminations, the adsorption reaction finished when reaching saturation-- a dynamic equilibrium established between the adsorption and desorption. To some extent, soil and plants play a N buffering container role. The adsorption and degradation coefficient of the growing and non-growing periods are 5.64l/d and 4.05l/d respectively. The adsorption features of soil and plants to nitrogen were deeply researched and revealed, so as to the wetlands ecosystem was understood properly and play the ecological function role fully.