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1.
DISSOLVED ORGANIC CARBON IN THE EAST CHINA SEA IN AUTUMN 总被引：1，自引：0，他引：1
ImODUcrIONThepoolofdissolvedorganicrnatter,eva1uatalasdissolvedorganiccarbonpoC),hasbostudndforrnanyycars(Med,l964,SkopintSevCtal.,l966).Continentalmar-ginshavedrihypotheSedtobeasirnPortanttothemarinecarbonbiogeochdricalCy-desasthedeepsea(Walsh,l99l),butinmostdiscussions,onlyexportofparticulateorganieswasconsidetal.HighconcentIationofDOCincoastalwatershasaspedlroleinexportingcarbonfromcontinentalmarginstotheopenocean.UndelstandingtheroleoftheoceanmarginsintheglobalcarbonCycAsdependsla… 相似文献
2.
Investigation of dissolved organic carbon (DOC) and particulate organic carbon (POC) at 12 stations in Yantal Sishili Bay in May, August, and November of 1997 and March and May of 1998 showed that DOC concentrations varied from 1.14 mg/L to 5.35 mg/L; that the average values at all staticrLs ineach entise varied from 1.52 mg/L to 2.12 mg/L; that POC concentrafions varied from 0.049 mg/L to 1.411mg/L; and averaged 0.159 mg/L to 0.631 mg/L in each cruise. Horizontal distribution of DOC was influ-enced by factors such as continental input, organism activity, temperature, aquieulture environment, etc. The higher POC concentration occurred along the coast. The vertical distribution of DOC and POC changed obviously in spring and summer, but not obviously in autumn and winter. DOC concentration was highest in summer and POC in spring; both were lowest in winter. The seasonal change of DOC was con-sistent with primary productivity seasonal variation, and that of POC was consistent with ehlorophyll-a sea-sanal variation. The seasonal change trend of the C/N ratio of dissolved organic matter was obvious, but the C/N ratio of particulate organic matter had no such trend. 相似文献
3.
DETERMINATION OF DISSOLVED ORGANIC CARBON IN SEAWATER USING UV/PERSULPHATE METHOD AND HTCO METHOD 总被引：5，自引：0，他引：5
MODUonONThermsurmtofdissolvedorganiccarbon.(DoC)inseawaterhasprovedtobeaddricultandcontroversialproedurepeenneretal.,l992,l993,OgawaandOgam,l992,Tanoue,l992).InterestinthemeasurernentofDOCinseaytteyintenSfomtlyinoonnographicdedes(Sharp,l993)largeyduetothesuggestionthathighteIneratU-rcatalyticoxidationanalysisyieklshighervaluesthanhaditionalweoxidationmethods(SugdriraandSuzuki,l988).Thereportedhigherconcenttationsappeatalsignilicantforg1obaloasnfluxmodelingcyoggweiler,l992)andforunderst… 相似文献
4.
长江中游平原区面临着一系列严重的地质环境问题，其中地下水铵氮和磷的问题十分突出，但目前对于二者共存规律的认识还十分薄弱。以长江中游沿岸故道区为典型研究区，对采集的地下水样品进行了水文地球化学分析，并综合运用因子分析和随机森林模型探讨了铵氮和磷的赋存规律。结果表明:地下水整体处于还原环境中，NH4-N的质量浓度为0.03~71.0 mg/L（均值9.92 mg/L），P的质量浓度为0.02~3.38 mg/L（均值0.51 mg/L）。地下水中高浓度的铵氮与磷均主要为天然成因，但铵氮与磷的迁移富集过程存在差异:铵氮的迁移富集与含氮有机质矿化过程密切相关；磷的迁移富集与铁氧化物或氢氧化物的还原性溶解密切相关，而含磷有机质矿化是磷富集的次要过程。Eh很低的地下水环境易产生高浓度铵氮的地下水，相对中等的还原环境会产生高浓度的磷但通常不会伴生高浓度的铵氮；当地下水中S2-，DOC，I均处于相对较高的浓度水平时会伴生大量的铵氮，而磷的浓度在很大程度上受控于Fe2+浓度；当DOC，I和Fe2+浓度都高时，通常会出现铵氮和磷浓度都较高的现象。 相似文献
5.
Preliminary study on the dissolved and colloidal organic carbon in the Zhujiang River estuary 总被引：3，自引：0，他引：3
ＩＮＴＲＯＤＵＣＴＩＯＮＥｓｔｕａｒｉｅｓｃｏｍｐｒｉｓｅａｍａｊｏｒｂｉｏｇｅｏｃｈｅｍｉｃａｌｉｎｔｅｒｆａｃｅｃｏｎｎｅｃｔｉｎｇｔｈｅｌａｎｄａｎｄｔｈｅｓｅａ (Ｍａｎ ｔｏｕｒａ,1 987) .Ｔｈｅｂｅｈａｖｉｏｒａｎｄｆａｔｅｏｆａｐａｒｔｉｃｕｌａｒｒｉｖｅｒ ｂｏｒｎｅｓｕｂｓｔａｎｃｅｉｎｔｒｏｄｕｃｅｄｉｎｔｏａｎｅｓｔｕａｒｙｉｓｄｅｔｅｒｍｉｎｅｄｔｏａｌａｒｇｅｅｘｔｅｎｔｂｙｔｈｅｂｉｏｇｅｏｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｓｕｂｓｔａｎｃｅａｓｗｅｌｌａｓｐ… 相似文献
6.
研制适用于三元复合驱采油污水工况条件下的MPM固体缓蚀阻垢剂,分析三元复合驱采油污水中MPM的电化学特性.结果表明:随着温度增加,20#钢在采油污水的腐蚀速率呈增加趋势,极化曲线显示钝化区表面材料在表面高温下处于钝化状态,产生的钝化膜能够降低腐蚀速度.在阻垢缓蚀剂质量浓度相同的情况下,不同温度的电化学阻抗谱在高频区出现容抗弧,显示优良的缓蚀性能.不同质量浓度MPM极化曲线表明,缓蚀率随MPM质量浓度的增加而增大,MPM极值质量浓度为80mg/L.污水体系中的Ca2+、Cl-对缓蚀率产生影响.MPM适用于高质量浓度Ca2+的三元复合驱采油污水处理. 相似文献
7.
Study on Algae Removal by Immobilized Biosystem on Sponge 总被引：2，自引：0，他引：2
PEI Haiyan HU Wenrong 《中国海洋大学学报(英文版)》2006,5(4):327-332
In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake＇s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time （HRT） was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preyingby microcreatures were the two main modes of algal removal, which occurred in two steps： first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures. 相似文献
8.
Endocrine disrupting chemicals (EDCs) are increasingly viewed as persistent pollutants, similar to natural hormones in function. This paper describes the expression profiles of 7 genes (DMRT, VTG, GnRHR, FSHR, CYP17A, CYP19A, and CYP19B) involved in sex steroid synthesis and action as well as sexual development in adult male and female Cynoglossus semilaevis, after exposure to different concentrations of Bisphenol A (BPA) and 17β-estradiol (E2). Both BPA (1, 10, 50, 125, and 250 mg/kg) and E2 (0.5, 5, and 10 mg/kg) induced changes in target gene expression, although the estrogenic effects of E2 as a model estrogen were stronger. Among the 7 genes, VTG, CYP17A and CYP19 responded strongly to BPA or E2 exposure and can thus serve as reference biomarkers for estrogenic EDCs exposure in marine teleosts. These data will provide a window to establish a hypothalamic-pituitary-gonadal model in C. semilaevis to better understand the effect pathways of EDCs. 相似文献
9.
Impact of Suspended Particles and Enhancement Techniques on Ultraviolet Disinfection of a Secondary Effluent 总被引：1，自引：0，他引：1
The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is difficult to achieve sometimes. The authors studied the particle size distribution, contribution of particle-associated Fecal Coliform （F. C. ）, and their influences on UV disinfection. A combined disinfection process （chlorination with a subsequent UV disinfection） was tested to improve the disinfection effect. The results indicated that the content of suspended solids, especially that of large particles, has a strong impact on UV disinfection efficiency; D〉 10 μm particles associated F.C. are difficult to be disinfected and are the main part of the tailings of F.C. inactivation curves. Pre-chlorination could decrease the number of particles in the secondary effluent and transform the large particles into small ones, reducing the influence of particles on UV disinfection and enhancing the resistance ability of the combined process to particle loading. 相似文献
10.
洞庭湖平原西部地区浅层承压含水层是当地主要的地下水开采层,却面临严重的水质型缺水问题,其中以铵氮异常最为典型,但目前对于其来源和富集机制的认识十分薄弱。以洞庭湖平原西部为研究区,沿区域地下水流方向对地下水样品进行水文地球化学分析,旨在查明地下水中铵氮的来源,揭示地下水流动对铵氮富集的控制机理。结果表明:NH4-N质量浓度为0.05~16.75 mg/L,且与DOC、HCO3-、As、Fe2+、Mn、P质量浓度呈现较好正相关性;而高质量浓度的NH4-N对应着很低质量浓度的Cl-、SO42-、NO3-和很低的Cl/Br比值,可以推测浅层承压水中的铵氮主要由天然有机质矿化作用产生,而非人为输入。沿着地下水流向,NH4-N和As、Fe2+、Mn质量浓度均显著升高,说明由于水流越来越滞缓,含水介质颗粒越来越细,沉积物有机质越来越富集,含氮有机质矿化作用逐渐增强,使得NH4-N质量浓度逐渐升高,并形成了还原性逐渐增强的地下水环境,相关地球化学过程产生的还原性组分（砷、铁、锰等）也逐渐富集。本研究进一步丰富了地下水原生铵氮的成因理论,可为当地的供水安全保障提供理论基础。 相似文献
11.
Photochemical production of dissolved inorganic carbon from suwannee river humic acid 总被引：1，自引：0，他引：1
The photochemical mineralization of dissolved organic carbon(DOC) to dissolved inorganic carbon(DIC) is a key process in carbon cycling.Using a Suntest CPS solar simulator,Suwannee River humic acid(SRHA) was photooxidated to examine the effects of O2 levels,the wavelength of incident light,and the concentration of Fe on the photoproduction of DIC.Increasing the O2 abundance enhanced photodegradation of SRHA.The rate of DIC photoproduction under air saturation in the first 24 h(4.40 μmol/(L h)) was increased... 相似文献
12.
Xiaolin Chen Shengfeng Yang Ronge Xing Huahua Yu Song Liu Pengcheng Li 《中国海洋大学学报(英文版)》2012,11(2):249-252
In this paper, studies were carried out to extract astaxanthin from discharged wastewater during the production of chitin and to reveal the scavenging effect of the obtained pigment on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Different ratios of dichloromethane/methanol (V/V) were used to extract astaxanthin. When the ratio of dichloromethane/methanol was 2:8 and the ratio between the mixed organic solvent (dichloromethane/methanol, 2:8, V/V) and wastewater was 1:1, the highest yield of pigment was obtained (8.4 mg/ 50 mL). The concentration of free astaxanthin in the obtained pigment analyzed by HPLC was 30.02%. The obtained pigment possessed strong scavenging ability on DPPH radical and IC50 was 0.84mg/ml. 相似文献
13.
《中国海洋大学学报(英文版)》2021,(4)
In order to explore the effect of carbon and nitrogen (C/N) ratio on the performance of anoxic/aerobic-moving bed biofilm reactor (A/O-MBBR) process for treating mariculture wastewater,a laboratory-scale A/O-MBBR was conducted.The results showed that the reduction of C/N ratio was conducive to improving the removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen (NH_4~+-N),while inhibiting that of nitrite nitrogen (NO_2~--N) and nitrate nitrogen (NO_3~--N).The extracellular polymeric substances (EPS) in anoxic zone were significantly higher in concentration than that in aerobic zone although they both declined with decrease of C/N ratio.The result provides solid support for better controlling the pollution of mariculture wastewater. 相似文献
14.
Sewage pollution in Negril, Jamaica: effects on nutrition and ecology of coral reef macroalgae 总被引：1，自引：0，他引：1
Coral reefs in the Negril Marine Park (NMP), Jamaica, have been increasingly impacted by nutrient pollution and macroalgal blooms following decades of intensive development as a major tourist destination. A baseline survey of DIN and SRP concentrations, C:N:P and stable nitrogen isotope ratios (δ15N) of abundant reef macroalgae on shallow and deep reefs of the NMP in 1998 showed strong P-limitation and evidence of increasing sewage pollution. In 1999, a sewage collection and treatment project began divertin... 相似文献
15.
On the basis of large amount of historical and measured data,this paper analyzed the regional,periodic,frequency,continuing,and response characteristics of droughts and floods in Zhejiang and proposed the conception of ratio of peak runoff.Main characteristics of droughts and floods in Zhejiang are as follows:1)The western Zhejiang region is plum rain major control area,and the eastern coastal region of Zhejiang is typhoon major control area.2)Within a long period in the future,Zhejiang will be in the long period that features droughts.3)In Zhejiang the 17th century was frequent drought and flood period,the 16th,19th,and 20th centuries were normal periods,while the 18th century was spasmodic drought and flood period.4)The severe and medium floods in Zhejiang were all centered around the M-or m-year of the 11-year sunspot activity period.5)There are biggish years of annual runoff occurred in El Ni?o year(E)or the following year(E 1)in Zhejiang.The near future evolution trend of droughts and floods in Zhejiang is as follows:1)Within a relatively long period in the future,Zhejiang Province will be in the long period of mostly drought years.2)Between 1999 and 2009 this area will feature drought years mainly,while the period of 2010-2020 will feature flood years mostly.3)Zhejiang has a good response to the sunspot activities,and the years around 2009,2015,and 2020 must be given due attention,especially around 2020 there might be an extremely severe flood year in Zhejiang.4)Floods in Zhejiang have good response to El Ni?o events,in El Ni?o year or the following year much attention must be paid to.And 5)In the future,the first,second,and third severe typhoon years in Zhejiang will be 2009,2012,and 2015,respectively. 相似文献
16.
采集采自山东某养殖场的栉孔扇贝(Chlamys farreri)健康贝和病贝的血淋巴,测定其血浆蛋白浓度、血浆蛋白图谱和相对分子质量,以及血浆抗菌活性、凝集素活性等几种重要的体液免疫因素,研究环境胁迫对血浆蛋白及其抗菌活性的影响。结果表明:栉孔扇贝(C.farreri)血浆蛋白质量浓度约1 260~1 650μg/mL;血浆蛋白SDS-PAGE图谱显示3条蛋白带,相对分子质量分别为34 000、25 000和14 000;健康贝血浆抗菌活性指数BI为0.34,病贝BI为0.21;凝集素活力水平为1.602~2.204。氨氮胁迫下血浆蛋白浓度下降约780μg/mL,凝集素活力下降为1.301;高温胁迫下血浆蛋白质量浓度下降约为900μg/mL,凝集素活力为1.903;高盐胁迫下血浆蛋白浓度下降约为990μg/mL,凝集素活力为2.204。 相似文献
17.
Zhen Tao Quanzhou Gao Wenping Guo Zhengang Wang Yongling Zhang Chenji Xie Xiakun Huang Hongwei Zhong 《山地科学学报》2011,8(5):694-703
A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological... 相似文献
18.
Chemical characterization and composition of dissolved organic matter in Jiaozhou Bay 总被引：1，自引：0，他引：1
Biologically utilizable dissolved organic compounds, including dissolved organic carbon (DOC), dissolved carbohydrates (DCHO)
and dissolved free amino acids (DFAA) were analyzed in filtered surface seawater samples collected at 19 stations in Jiaozhou
Bay, China, on June 3, 2007. In these samples, concentrations of DOC, dissolved free carbohydrates (DFCHO), dissolved combined
carbohydrates (DCCHO), total dissolved carbohydrates (TDCHO) and total dissolved free amino acids (TDFAA) ranged from 141.7
to 191.1 μmol C/L, 1.98 to 18.18 μmol C/L, 5.04 to 24.90 μmol C/L, 14.52 to 30.36 μmol C/L, and 1.83 to 11.89 μmol C/L, respectively.
As a major component of the dissolved carbohydrates, the concentrations of DCCHO were about three times higher than those
of DFCHO. Three major constituents of the DFAA were threonine (23.0±5.7 mol%), glutamic acid (16.6±3.2 mol%) and arginine
(9.1±3.3 mol%). Based on the composition of DFAA, a molar C:N ratio of 3.60±0.75 in DFAA was derived, indicating longer carbon
chains in the amino acids. DCCHO (8.1%) was the most abundant fraction of DOM in most samples, followed by DFCHO (4.8%) and
TDFAA (2.7%). These DOM concentrations displayed a decreasing trend from the coast to the central region. Significant correlations
were found between the DCCHO and DFCHO concentrations (r=-0.724, n=19, P<0.001) and the DCCHO and TDCHO concentrations (r=0.506, n=19, P=0.027). 相似文献
19.
Dissolved organic carbon (DOC) is an important component of the terrestrial carbon cycle. However, the sources and controlling factors of DOC in soils remain uncertain. In this study, the effects of nitrogen (N) amendment and crop growth on DOC in soil solution were examined at a maize-wheat rotated field located in the central Sichuan Basin in southwestern China. Nitrogen treatments in this study included 150 kg N ha-1 season-1, 200 kg N ha-1 season-1 and the control without any fertilizer application. During the whole experimental period, we observed significant decreases (p<0.05) in DOC concentrations in the sampled soil solutions associated with increase in N inputs at the bare soil plots, but no change in DOC at the plots with crop growth. The estimated average contributions of plantderived DOC were 16%, 24% and 32% of total DOC in the summer maize season and 21%, 32% and 38% in the winter wheat season along with the gradient of N fertilizer application rates. The results implied that the crop growth could play a key role in the soil DOC production, and the N input enhanced DOC production by increasing crop growth. The relationship between the DOC concentrations and the crop root biomass was statistically significant for both the maize and winter wheat seasons. Our observations indicated that crop growth exerted greater influence on the seasonal variability of DOC concentration in soil solutions at the experimental site, which overwhelmed the effect of soil native organic matter decomposition on DOC concentrations in soil solutions. 相似文献
20.
The effects of estuarine processes on the fluxes of inorganic and organic carbon in the Yellow River estuary 总被引：1，自引：0，他引：1
Riverine carbon flux is an important component of the global carbon cycle. The spatial and temporal variations of organic
and inorganic carbon were examined during both dry and wet seasons in the Yellow River estuary. Concentrations of dissolved
organic carbon (DOC) and dissolved inorganic carbon (DIC) in the Yellow River during dry seasons were higher than those during
wet seasons. The effective concentrations of DOC (CDOC*) were higher than the observed DOC at zero salinity. This input of DOC in the Yellow River estuary was due to sediment desorption
processes in low salinity regions. In contrast to DOC, the effective concentrations of DIC were 10% lower than the DIC measured
at freshwater end, and the loss of DIC was caused by CaCO3 precipitation in low salinity region. Particulate organic carbon (POC) and particulate inorganic carbon (PIC) contents of
the particles stabilized to constant values (0.5%±0.05% and 1.8%±0.2%, respectively) within the turbidity maximum zone (TMZ)
and showed no noticeable seasonal variations. A rapid drop of PIC and rise of POC occurred simultaneously outside the TMZ
due to an intense dilution of riverine inorganic-rich particles being transported into a pool of aquatic organic-poor particles
outside the TMZ. Annually, the Yellow River transported 6.95×105 t of DIC, 0.64×105 t of DOC, 78.58×105 t of PIC and 2.29×105 t of POC to the sea. 相似文献