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1.
Duetoregionalhydrogeologicandclimaticconditions,inthewesternSongnenPlain,themostdistinctcharacteristicofwaterenvironmentinlimnicwetlandsisthatmanywaterbodieshavehighsaltcontentsandpHvalues,andsomelimnicwetlandsbelongtosaltmarshes.Thelimnicwetlandsofthisregionarespecialnaturecomplex.Itisimportantfortheutilizationofwetlandresourcesandtheintegrateddevelopmentofsaline-alkalinesoiltostudychemicalcharacteristicsofwaterenvironmentinthisregion.1NATURALENVIRONMENTCHARACTERISTICSOFTHEWE…  相似文献   

2.
GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY, CHINA   总被引:13,自引:0,他引:13  
1INTRODUCTIONGroundwater in Changchun City assures about 45% of total water supply. Drinking water supply of Chang-chun City was mostly served by surface water from Shitoukoumen and Xinlicheng reservoirs located in the east and south of the city (ZHANG, 1993). However, with the development of urban construction the ground-water especially from deep boreholes is also used for drinking purpose in suburban areas. The urbanization process in Changchun City threatens the groundwater quali…  相似文献   

3.
IINTRODUCTION been used to Interpret waterqualltycharacteristlcs(SHEN,1994).In fact,the temporal changes of waterSince the 1930s,river water quality has been one quality parameters have ceFtaln re剖larfluctuatlons withof the main topics of water environmental sciences.their own spectrum characteristic and causes.However,Since the 1980s,global change has become the hot spot waterquallty average will lose this statisticall讪matlonOearth science a…  相似文献   

4.
DuringthethreeMt.QomolangmaExpeditionsof1959-1960,1966-1968and1975,ChinesescientistshadobtainedmanydataofglaciersinthedistrictofMt.Qomolangma(Wangetal.,1980;Xieetal.,1975;Zhangetal.,1975).InMay1997,Prof.QinDaheandProf.PaulA.Mayewskiorganizedanothe…  相似文献   

5.
The densities of 36 water samples from the Huanghe River estuary and Bohai Bay were determinedby a magnetic float densimcter under three temperatures from 15℃ to 25℃.All the measured densities ofsamples were greater than that of the values calculated from the International Equation of State of Seawater.The differences between the measured and calculated densities increased with the decrease of salinities.The dif-ferences appeared exponentially correlated with[Ca~(2+)]/s,[Mg~(2+)]/s and[SO_4~(2-)]/s,and had"s"type curverelationship with the alkalinity in all salinity range.But in the salinity ranging from 25.72 to 31.57,therelationships were all linear.The density difference can be estimated from the equation △ρ(10~3kg·m~(-3))=(-2.79+236.5([Ca~(2+)]/s)/(-9.7464×10~(-3)+[Ca~(2+)]/s).It was the high alkalinity and[Ca~(2+)]/s that resulted in the measured densi-ties of seawaters being higher than the calculated densities in the Huanghe estuary and Bohai Bay.  相似文献   

6.
The International Eq一lation of State of Seawater,1980 and the PraeticalSalinity Scale,1978 have been adoPted by theUNESCO江CES沼COR八APSOJoint Panel ono‘eanogral,hie Tables and Standards(JPOTS),and endorsed bythese organizati6ns(Miller‘〕and Poisson,1981;Uneseo,1981).Th已new equa-tion and the Praetieal Salinity Seale are to be used for all values Published fromJan .1,1982 .The new equation 15 aeeurate for use in all oeeanie surfaee waters,but eannot be aeeurately aPPlied to…  相似文献   

7.
Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension and oil-field produced water. The bacterial strain was identified as Klebsiella sp. MYC according to its morphological and biochemical characteristics and 16SrDNA sequence. The optimal medium for bioflocculant production by this bacterial strain was composed of cane sugar 20 g L^-1, KH2PO4 2 g L^-1, K2HPO4 5 g L^- 1, ( NH4)2SO4 0.2 g L^-1, urea 0.5 g L^- 1 and yeast extract 0.5 g L^- 1, the initial pH being 5.5. When the suspension of kaolin clay was treated with0.5% of Klebsiella sp. MYC culture broth, the flocculating rate reached more than 90.0% in the presence of 500mg L^-1 CaCI2, while the flocculating rate for oil-field produced water was near 80.0% in a pH range of 7.0 - 9.0 with the separation of oil and suspended particles from the oil-field produced water under similar conditions. The environment-friendly nature of the bioflocculant and high flocculating rate of the strain make the bioflocculant produced by Klebsiella sp. MYC an attractive bioflocculant in oil-field produced water treatment.  相似文献   

8.
A great quartity of cosmic dust(spherules) was found in deep-sea sediments during May to July,1983manganese nodule investigations by the R/V“XIANGYANGHONG 16”in the area 7°-11°N,167°-178°Win the Pacific.Comprehensive study of the cosmic dust and determination with Laser Raman MolecularMicroprobe(LRMM) of the molecules in it showed that besides Fe-Fe,Fe~(3+)-O,Fe-Ni,Al-O,Fe-Obr-Si and Si-Onb,it also contained the organic molecules C-H-O and C-H-S-O,various no fixed form molecules of C,CH_2,CH_3 and volatile molecules CO_2,H_2O,OH~- and H_2S,etc…The study result has very important applications for exploring the origin of interplanetary dust parti-cles and life material.  相似文献   

9.
Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of sodium tripolyphosphate (STPP). The optimum temperature and pH for the TPPase of myosin subfragment-1 were 30℃ and pH 5.0, and at pH 8.0 the TPPase also showed a high activity. Mg2 was necessary to TPPase. The TPPase activity of myosin subfragment-1 was activated by Mg2 under low concentrations, but was inhibited when the concentration was over 17 mmolL-1. The TPPase activity was also affected by KCl. The optimum concentration of KCl for TPPase was 0.3 molL-1 under the condition of 17 mmolL-1 Mg2 . The TPPase activity was significantly inhibited by EDTA-Na2. Reagents such as KBr, KI and KIO3 could inhibit the TPPase effectively. K2Cr2O7 as well as KMnO7 and KNO3 exhibited weak inhibiting effects. The TPPase converted STPP to pyrophosphate (PP) and orthophosphate (Pi) stoichiometrically with a KM of 3.2 mmolL-1.  相似文献   

10.
In glacierized catchments, glacier runoff typically shows a strong diurnal cycle in the ablation season (June-September). To elucidate the effect of these processes on the chemical weathering, fresh snowfall and water samples were collected and studied from the supraglacial river, proglacial river, and gauging site in Qiyi glacierized catchment Qilian Mountains, Northwestern China, in the summer of 2011. The pH and electronic conductivity (EC) were determined in the field, and the concentrations of major ions (Na+, K+, Mg2+, Ca2+, Cl-, SO42-, NO3-) were measured. The results indicated that EC linearly increased with increasing distance from the glacial snout, and the concentrations of major ions increased with increasing water-rock interaction time. Along the flow path of the glacier runoff, Na+ and Cl- are more concentrated than other ions in the supraglacial river while Mg2+ and SO42- are more concentrated than other ions at the gauging site. The discharge, pH, EC, and the concentrations of major ions exhibited significant diurnal variation along the flow path. On the other hand, the amplitude of variation diminished from upstream to downstream along the flow path. The chemical weathering rate (Na++K++Mg2++Ca2+) was determined to be 10.9 t/yr/km2. Moreover, further research indicated that the sampling method influenced the assessment of chemical weathering rates. When the sample was collected randomly in one diurnal cycle of hydrography, the estimated ionic flux could deviate -47%~73% based on estimated hourly data. In contrast, if three samples were collected at peak, base flow and the discharge decreasing rate starts to slow down in one diurnal cycle of hydrography, respectively, the deviation would be less than 15%. The smaller the diurnal variation of discharge, the smaller deviation calculated.  相似文献   

11.
1 INTRODUCTIONItisveryimportanttorealizethedistributionsofpollutantsbeforethepollutioncanbecontrolledsuc cessfully .Owingtothelackofsystematicalobserva tionsinabroadarea ,numericalsimulationhasbe comeapowerfultooltounderstandthedistributionsofpollutantsa…  相似文献   

12.
Branchiura sowerbyi in the Donghu Lake (Wuhan, China) completes its life cycle in one year. Its production rates were 6.7 g m−2 yr−1 (wet weight) during the period from April 1962 to May 1963 and 8.6g m−2 yr−1 during the period from August 1963 to August 1964. The standing stocks in corresponding periods were 1.9g m−2 (wet weight) and 1.1g m−2, and theP/B ratios were 3.6 and 7.8. Based on the standing stock during 1973–1975, an evaluation of recent productin levels ofB. sowerbyi in Donghu Lake has also been made (i.e. 5.7–33.5g m−2 yr−1).  相似文献   

13.
The effect of Mg2+, NaCl and citric acid on the accumulation of β-carotene inDunaliella Salina was studied. The experimental results showed that 10.5 mmol/L Mg2+, 5 mol/L NaCl, 3 μmol/L citric acid, and CO2 are favorable forDunaliella Salina cell growth and β-carotene accumulation. After 144 h culture under the above conditions, theDunaliella Salina biomass increased by 7.18 times; β-carotene reached 9.61%. Project 89023990 supported by the Shandong Natural Science Fund.  相似文献   

14.
Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO3^--N, NO2^--N, NH4^ -N, SIO3^2--Si, PO4^3--P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq. ( 1 ) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temperature; that the main factor controlling the primary production is Si; that water temperature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecological niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature‘s effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay, the biogeochemical sediment process of the silicon, the phytoplankton predominant species and the phytoplankton structure. The authors considered silicate a limiting factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and uptake by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrinsic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant-nutrient concentTations but low phytoplankton biomass in some waters is reasonably explained in this paper.  相似文献   

15.
This study on dynamic changes of culture color,astaxanthin and chlorophylls,inorganic N including N-NO3^-,N-NO2^- and N-NH4^ in batch culture of Haematococcus pluvialis exposed to different additive nitrate concentration showed(1)ast/chl ratio was over 0.8 for brown and red algae,but was usually less than 0.5 for green and yellow algae;(2)N-NO3^-,in general,was unstable and decreased,except for a small unexpected increase in nitrate enriched treatment groups;(3)measurable amounts of N-NO2^- and N-NH4^ were observed respectively with three change modes although no extemal nitrite and ammonia were added into the culture;(4)a non-linear correlation between ast/chl ratio(or color)changes and the levels of N-NO3^-,N-NO2^-,N-NH4^ in H.pluvialis culture;(5)up and down variation of the ast/chl ratio occurred simultaneously with a perceptible color change from yellow to brown(or red)when N-NO3^-,N-NO2^- and N-NH4^ fluctuated around 30,5,5μmol/L respectively;(6)existence of three dynamic modes of N-NO3^-,N-NO2^- and N-NH4^ changes,obviously associated with initial extemal nitrate;(7)the key level of total inorganic N concentration regulating the above physiological changes during indoor cultivation was about 50 μmol/L;and(8)0.5-10mmol/L of nitrate was theoretically conducive to cell growth in batch culture.  相似文献   

16.
1 INTRODUCTION Chironomid larvae are main groups in most aquatic ecosystems, playing a crucial ecological role in decomposition of detritus and material ex- changes between water column and the sediment (Liang et al., 1995a, b; Chen, et al., 1982). They a…  相似文献   

17.
Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values,concentrations of heavy metals (Cu, Pb, Zn and Cd) and nutrients (NH4^-, NO3^-, PO43^-, SiO32^-) were performed.Results indicate that concentrations of most of the heavy metals and nutrients in rainwater show clear seasonal variation, i.e. high level in winter and low level in summer. Regionally, concentrations are higher in the southern Yellow Sea than in the East China Sea, but the annual input of heavy metals into oceans by wet deposition is similar in both stations. However, the input of nutrients by wet deposition in the East China Sea is 2-3 times higher than that in the southern Yellow Sea. In individual, Pb and PO4^3- are input to the sea mainly by dry deposition; whereas Cu, Zn, Cd and N compounds are input dominantly by wet deposition, the N/P ratios in the rainwater from two stations are much higher than those in seawater, showing a significant impact of atmospheric wet deposition on marine production and biogeochemical circulation of nutrients in these sea regions.  相似文献   

18.
Effects of salinity, pH, nitrogenous and phosphate nutrients on the growth rate of four species of benthic diatoms were studied by using the method of in situ optical density measurement. The optimal culture conditions for the four species of diatoms are as follows: forAmphora coffeaeformis, s 35; pH 8.5; NO3 −N 1.54, NH4 +−N, 7.0; CO (NH2)2−N, 2.5 (mg/L); PO4 3−−P 1.13 (mg/L); forCocconeis scutellum varparva, s 30; pH 8.5; NO 3 −N 3.08, NH 4 + −N 3.5, CO(NH2)2−N 5.0 (mg/L); pO 4 3− −P 0.283 (mg/L); forNavicula corymbosa s 25; pH 8.0; NO 3 −N 1.54, NH 4 + −N 3.5 CO(NH2)2−N 5.0 (mg/L); PO 4 3− −P 0.565 (mg/L); forNavicula mollis. s 25; pH 8.0; NO 3 −N 1.54, NH 4 + −N 1.75, CO(NH2)2−N 1.25 (mg/L); PO 4 3− −P 0.141 (mg/L). Part of the results of this paper were exchanged in the Fourth Asian Aquaculture Forum. Oct. 16–20. 1995. Beijing, P. R. China.  相似文献   

19.
Hyper-spectrum models for monitoring water quality in Dianshan Lake,China   总被引:1,自引:0,他引:1  
The correlation between water quality parameters and hyper-spectral reflectance is studied with models established for each parameter and applied in Dianshan Lake, in the upstream of the Huangpu River running through Shanghai, China. Models are for dissolved oxygen (DO in mg/L): R720/R680 = 20.362×(R720/R680)2-31.438×(R720/R680)+19.156; for turbidity (NTU): R*714.5 = 206.07× (R*714.5)2-582.5×R*714.5 + 423.24; and for total phosphorus (TP in mg/L): R*509.5 = 16.661× (R*509.5)2-32.646×R*509.5+16.116. The R2 values are 0.770 8, 0.660 4 and 0.738 7, respectively, showing strong positive relationships. The models were then applied to assess water quality of different times. Results are quite satisfactory for some samples.  相似文献   

20.
A laboratory experiment was conducted to assess the bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and 100 μg mL−1). The growth of S. platensis was adversely affected by Pb2+ at high concentrations (30, 50 and 100 μg mL−1). However, at low concentrations (5 μg mL−1), Pb2+ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL−1 treatment group. The LC50 (96 h) of Pb2+ was measured as 75.34 μg mL−1. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL−1), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb2+ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g−1 dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure concentrations. S. platensis is able to tolerate considerably high Pb2+ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters.  相似文献   

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