共查询到20条相似文献，搜索用时 31 毫秒
1.
1. The adsorption action of basic zinc carbonate adsorbent on uranium in natural seawater can be expressed with the following formula of adsorption isotherm:C=k(U*)n = 8.51× 10-1(U*)0.49,where C is the concentration of uranium on adsorbent; U* is content of uranium in natural seawater employed.2. when the quantity of basic zinc carbonate adsorbent (T) is constant, with the increase of natural seawater quantity through the adsorption column (G), also increased are the adsorption content of uranium of the adsorbent (U), the concentration of uranium on the adsorbent (C) and the concentration of residual uranium (C0*) in natural seawater after adsorbing uranium, while the rate of recovery of uranium (R) is decreased. With the increase of (G) the coefficient of distribution (Kd) decreases to a certain value and then a little rises again. 相似文献
2.
3.
MECHANISM OF URANIUM ADSORPTION ON AMIDOXIME RESIN 总被引：1，自引：0，他引：1
The mechanism of uranium adsorption from seawater by polyacrylamidoxime resin is investigated by means of the experiments of adsorption isotherm and adsorption rate. The uranium uptake increases with the adsorption temperature and varies with the pH of seawater. Thermochemical and kinetic calculation show that the enthalpy change (△H) and the activation energy (E) of the uranium adsorption are 42.4 42.4 kJ mol-1 and 41.2 kJ mol-1 respectively, indicating that the uranium adsorption on the resin proceeds via a certain complex chemical reaction in which the amidoxime group in the resin chelates uranyl ions. 相似文献
4.
I. INTRODUCTION AHP resin is a new type of adsorbent and has been studied by the units concernedfor several years. There is little report about this work so far. AHP resin was synthesizedin aqueous phase with tetra-ethylene pentamine (TEPA), epichlorohydrin (ECH) andC-reagent as raw materials, and basic zinc carbonate (P_Z_n) and rubber solvent oil (120Gasoline) as pore-forming material. Compared with the technique of the amorphous lumpresin and that of the resin synthesized in oil phase, the new technique of resin synthesizedin aqueous phase manifests many advantages, such as raising the capacity of uranium-adsorption of the resin, simplifying the after-treatment process, reducing the cost, etc. Sea water, in which all kinds of cation and anion exist, is a system of electrolytes,and the concentrations of many ions are higher than the concentration of uranium for 相似文献
5.
The adsorption of Pb2+ and of Cd2+ ions from calcareous Krka river water of various salinities (3, 14, 20 and 38 psu) on calcite (CaCO3, Merck p.a.) was investigated. Simultaneous adsorption of Pb2+ and Cd2+ ions was studied as well. The results suggest that the two ions are adsorbed at different calcite surface sites; Pb2+ remained firmly bound to calcite at all salinities, whereas Cd2+ was firmly bound at low salinities and released at high salinities. Dissolved natural organic ligands at the freshwater-seawater interface (FSI; at 14 psu) promoted and below the FSI (at 20 psu) decreased the adsorption of Cd2+. The experiments were performed at metal concentrations of 8 × 10−8 mol l−1 and at natural pH values around pH 8. Adsorbed amounts of trace metal ions were determined in filtered samples by differential pulse anodic stripping voltammetry (DPASV) with a three-electrode system, after 24 h of equilibration with calcite. Several adsorption models were tested, such as Freundlich's, Langmuir's and Schindler-Stumm's surface coordination model. Adsorption isotherms belong to S-1 class of empirical adsorption isotherms. None gave reasonable values of adsorption constants. The fractional partitioning of adsorbent to the solid phase when normalized to the quantity of adsorbent present (Kd) declined as solid concentration increased. It was found that the surface charge is not responsible for the observed effect. Instead, aggregate size increased, which effected a loss in surface area. This is a reasonable explanation for the observed S-shaped adsorption isotherms curves. 相似文献
6.
舟山近海日本囊对虾野生群体与越冬养成群体形态性状对体重和肉重影响的比较 总被引：4，自引：2，他引：2
于舟山近海日本囊对虾(Marsupenaeus japonicus)海捕野生群体和露天池塘越冬养成群体中各随机选取150尾作为测定样本,依次测量其体重(Y1)、肉重(Y2)、体长(X1)、头胸甲长(X2)、胸宽(X3)、胸高(X4)、第二腹节长(X5)、第二腹节宽(X6)、第二腹节高(X7)、尾节长(X8)、尾节宽(X9)、尾节高(X10)、眼径(X11)、眼窝距(X12)、额剑长(X13)、额剑上缘锯齿数(X14)等16项表型性状,并采用相关分析、通径分析和偏回归分析等方法定量研究了日本囊对虾形态性状对野生海捕群体与露天越冬养成群体体重和肉重的影响效应。结果表明:(1)两实验测定群体的体重和肉重与本研究中除X14外的其它形态性状的相关系数均达到极显著水平(P0.01);(2)经通径分析,海捕野生群体被保留的形态性状与体重和肉重的复相关指数分别为0.944和0.837,露天越冬养成群体被保留的形态性状与体重和肉重的复相关指数分别为0.955和0.907,其中影响露天越冬养成群体体重和肉重的核心变量均为X1,重要变量依次为X2和X6,影响海捕野生群体体重和肉重的核心变量分别为X1和X2,重要变量均为X6;(3)经多元回归分析,得出了用于估算海捕野生群体体重和肉重的回归方程以及估算露天越冬养成群体体重和肉重的回归方程。 相似文献
7.
日本的海水化学资源提取技术研究 总被引：3，自引：0，他引：3
海水化学资源例如铀、锂提取技术已进入海水现场小规模试验。以纤维状偕胺肟类化合物为吸附材料 ,每公斤吸附剂的提铀量为 1 g。添加质量分数为 2 0 %聚氯乙烯的尖晶石型锰氧化物粒状海水提锂吸附剂 ,每克吸附剂的提铀量为 1 8mg。浮体式吸铀装置可用于深海作业。流动床或船舶提锂系统 ,可规模化海水提锂。吸锂剂的脱附以及脱锂液的浓缩分离已初步达到小型生产的程度。用吸附法从海水中提取的碳酸锂纯度达 99%以上 ,海水锂回收率为 2 7%。 相似文献
8.
壳色是影响商品贝类经济价值的重要性状。本研究以不同壳色的硬壳蛤（Mercenaria mercenaria）群体为繁殖亲贝，采用个体间随机交配的方法，成功选育了白、红和杂3种壳色的子代群体，并在池塘培育至360日时测量了其壳长（X1）、壳高（X2）、壳宽（X3）及活体质量（Y），并使用相关性分析、主成分分析和通径分析等方法，探究了不同壳色硬壳蛤在幼虫期和稚贝期的生长性状差异及壳形态性状（壳长、壳高、壳宽）对活体质量的影响。研究结果表明：在幼虫期，与白色和红色群体相比，杂色群体生长速度更快、变态率更高，但存活率低（P<0.05）；在稚贝期，白色群体表现出显著的生长优势（P<0.05）。相关性分析结果显示，3种壳色硬壳蛤的壳形态性状（X1、X2、X3）与活体质量（Y）的相关系数均达极显著水平（P<0.01）。主成分分析和通径分析结果表明，硬壳蛤的壳长（X1）是影响其活体质量（Y）的主要因素。本研究结果能够为不同壳色硬壳蛤良种选育提供重要理论依据和基础数据。 相似文献
9.
为研究硬壳蛤形态性状对体质量(Y)、软体质量(Y1)及肥满度(K)的影响,测量硬壳蛤的壳长(X1)、壳宽(X2)、壳高(X3)、体质量(Y)和软体质量(Y1)等指标,并进行相关性分析、多元回归分析和通径分析。结果表明:体质量变异系数最高,壳宽与体质量相关系数最高(0.970)、壳长与软体质量相关系数最高(0.946)、壳长与肥满度相关系数最高(0.203)。壳宽对体质量直接作用最大(0.145)、壳长对软体质量直接作用最大(1.113)、壳长对肥满度直接作用最大(1.752)。形态性状与体质量、软体质量及肥满度的多元回归方程分别为Y=–46.359+0.288X1+1.723X2+0.640X3,R2=0.949;Y1=–6.607+0.301X1+0.157X2–0.161X3,R2=0.901;K=3.159+0.173X1+0.008X2–0.179X3,R2=0.072。壳宽是影响硬壳蛤体质量的主要因素,壳长是影响硬壳蛤软体质量的主要因素,各性状与肥满度回归关系不显著,个体间肥满度差异大。研究结果可为硬壳蛤选育及苗种繁育提供参考。 相似文献
10.
11.
The distribution of molecular masses of organic ligands for copper(II) in oceanic water was investigated. The bulk dissolved organic matter (DOM) was fractionated by ultrafiltration and organic ligands were extracted from the resultant fractions by using immobilized metal ion affinity chromatography (IMAC). Contributions of total organic ligands were 2.0–4.4% of the bulk DOM in surface waters, as determined by the UV absorbance. In the distribution of molecular masses of organic ligands, relative contribution of the fraction with low molecular masses (<1000 Da) was dominant (49–62%), while 26–33% of the total organic ligands was in the 1000–10,000 Da fraction, leaving 10–19% in the >10,000 Da fraction. The distribution of molecular masses of organic ligands shifted to higher molecular masses, as compared with that of the bulk DOM. The fluorescence intensities of organic ligands were shown to be associated with carboxyl contents, based on peak excitation/emission wavelengths and the pH-dependence of fluorescence. Two ligand classes with different conditional stability constants (log KCuL′≈7 and 9) were determined from fluorescence quenching of ligand fractions during copper(II) titration. Organic ligands in low molecular mass fractions were relatively weak and strong ligands occurred in higher molecular mass fractions. It is suggested that the weaker ligand sites would consist of two or more carboxyl groups (log KHL′=4), whereas carboxyl groups (log
=2), which are protonated at lower pH, and primary amine may additionally contribute to the formation of more stable copper(II) complexes of the stronger ligand. 相似文献
12.
Lars Chresten Lund-Hansen Morten Pejrup Jens Valeur Anders Jensen 《Estuarine, Coastal and Shelf Science》1994,38(6)
Gross sedimentation rates (GSR) have been measured using sediment traps placed at nine different levels above the bed (0·3, 0·5, 0·8, 1·0, 2·0, 4·0, 6·0, 8·0 and 10·0 m). The sediment traps were deployed for 1·25 years and recovered 28 times during the study period. Low average GSR values of 5·5 g m-2 day-1 were obtained at 10·0 m, and high average GSR values of 114·8 g m-2 day-1 were obtained at 0·3 m. An expression for the eddy diffusion coefficient of suspended particulate matter (Ks), based on the measured GSR is given. The expression has been used for modelling of Ks at the different trap levels above the bed. High values (≈42 cm2 s-1) of Ks were obtained at the upper traps, whereas low values (≈2 cm2 s-1) were obtained near the bed. Comparison between level of turbulent energy in terms of shear stress at the boundaries of the water column, i.e. from the wind and the bed flow, showed that wind energy exceeded that of the bed flow by a factor 16. At 5·0 m Ks was positively correlated (r=0·66) to the eddy diffusion coefficient of momentum (Km) derived from the wind energy transfer to the water, giving an average β of 0·5 for Ks =βKm. The density difference between surface and bottom waters has been designated a parameter of stratification, and is discussed in relation to variations of Ks and Km . 相似文献
13.
The adsorption behaviour for uranium of four kinds of amidoxime resinst RNH, RCH, RAH and RPH in seawater has been investigated. It has been found that all these resins are capable of adsorbing rapidly uranium from U-cnriched seawater with a high uranium uptake.RNH was able to adsorb uranium satisfactorily from natural seawater, and the uranium uptake of RNH with a degree of cross-linking of 3-5 mol % was above 200 μg/g-R (adsorption for 15 days). The uranium uptakes of RCH, RAH and RPH from natural seawater were much lower than the uranium uptake of RNH. The factors which caused the difference between resins RCH, RAH, RPH and resin RNH are discussed. 相似文献
14.
15.
为了研究密度胁迫对卵形鲳鲹(Trachinotus ovatus)鱼苗运输水质、存活率、免疫酶活力和血清生化指标的影响,确定适宜的运输密度,为卵形鲳鲹鱼苗的科学运输提供参考依据。对卵形鲳鲹鱼苗(体长为5.36cm±0.60cm,质量为3.04g±0.71g)采用塑料袋密闭充氧运输方式,在3个不同运输密度下(D1=9 kg/m~3、D2=12 kg/m~3、D3=15 kg/m~3)模拟运输8 h,对比运输不同密度卵形鲳鲹鱼苗对运输水质、鱼苗存活率、肝脏免疫酶活力和血液生理生化指标的影响程度。结果表明, 3个密度组的卵形鲳鲹鱼苗的存活率均为100%,经运输后暂养72 h的存活率仍为100%。经塑料袋密闭充氧运输8 h后, 3个密度组的运输水体的DO含量无显著变化,运输水体温度(T)和pH值随运输密度的增加而降低, NH_4-N含量随运输密度的增加而上升,其中NH_4-N的含量显著高于对照组。肝脏组织中, D1、D2、D3的总超氧化物歧化酶(T-SOD)活力无显著差异(P0.05,下同),而高运输密度组(D3)对比对照组,两组的T-SOD活力变化存在显著差异(P0.05)。密度运输胁迫组乳酸脱氢酶(LDH)活力显著高于对照组水平,D2、D3无显著差异,显著差异于D1组。过氧化物酶(POD)活力D1、D2、D3组无显著差异,但均显著低于对照组。3组实验组的过氧化氢酶(CAT)活力均显著高于对照组且组间无显著差异。血清中, D1、D2组的CRE活力显著低于对照组,但D3组又显著高于对照组。D1、D2、D3的血清中皮质醇(COR)活力无显著差异,但显著高于对照组。D2、D3的葡萄糖(GLU)含量与对照组无显著差异, D1显著低于对照组。D1、D2、D3 3个运输密度组的谷丙转氨酶(GPT)与谷草转氨酶(GOT)活力均显著高于对照组。同时, D1与D2组的GPT活力显著低于于D3组,但GOT活力显著高于D3组。密度胁迫对卵形鲳鲹鱼苗的运输存活率无影响,但对运输其的水质、免疫酶活力及血清生化指标均有影响。在实际运输中,采用塑料袋密闭充氧运输,运输时间时长为8 h以内,运输密度设定为15 kg/m~3的卵形鲳鲹鱼苗为宜。 相似文献
16.
-The i. r. spectra of Na4 [UO2 (CO3)3], Na [UO2 (OH)3] and the surface species of uranium on HTO underthe condition of flowing natural seawater and concentrated seawater (NaCl-NaHCO3-U) were recorded, with the bands of urany! of surface species obtained and the finding that iigands of surface species besides HTO are mainly water and OH, and there are some CO32- groups under the condition of natural seawater. Some relations between the complex properties and the j. r. spectroscopic characters for uranyl complexes were studied, and the transferred change quantity of surface complex was calculated.Structure models for surface species of adsorption are herein presented and the mechanism for uranium adsorption is deduced. 相似文献
17.
于1990年10月 - 1992年7月在室内条件下测定黄河中游乌拉特前旗、包头黄河大桥及清水河地段水体中天然配体与铜、铅、锌、镉反应的络会容量（C?C），计算总条件稳定常数（K）和络合容量指数（I）。实验证明：乌拉特前旗水体中络合客量最大，包头和清水河相近。络合容量顺序为：Cu＞Zn＞Cd＞Pb，和可溶性有机碳及碳酸盐分析结果一致。总条件稳定常数为：KPbL最大，KCuL，KZnL，KCdL相近。和长江水做了比较。络合容量指数在IgK相近情况下，随络合容量增大而增大。 相似文献
18.
19.
Adsorption kinetics of the interaction between Pt, Pd and Rh(defined here as platinum group elements, PGEs)ions and macromolecular organic compounds(MOCs, 10 kDa), including humic acid, carrageenan and bovine serum albumin, and different cutoff fractions of natural organic matter(1 kDa and 3 kDa) obtained from seawater using centrifugal ultrafiltration devices were investigated. For a given element, all the adsorption kinetics did not reach equilibrium except the interaction between Pt and 1 kDa cutoff, and between Pd and humic acid.For all the tested MOCs, the adsorption kinetics could be divided into two stages, a rapid adsorption process in the first 8 h and the desorption stage after the first 8 h until the equilibrium. The change trend of partition coefficient(log_(10)K_d) values with experiment time was consistent with that of the kinetic curves. However, in the interaction between PGE ions and natural dissolved organic matter(NDOM), an obvious difference in the change trends of log_(10)K_d and kinetic curves was observed. It indicated that the partition behavior of PGE ions interacting with NDOM in seawater was a combined effect of different organic constituents. The adsorption and log_(10)K_d of PGEs in the 1 kDa NDOM fraction were higher and more stable than those in the 3 kDa NDOM fraction. The results also indicated that the 1–3 kDa NDOM may dominate the interaction between PGEs ions and NDOM. Moreover, no kinetic model could perfectly simulate the adsorption process. It indicated that the colloidal struction and morphology of MOCs or NDOM in seawater might be inhomogeneous. Hence, the interaction between PGE ions and organic matter in seawater was a complicated process and needs further research. 相似文献
20.
Mixed and mixing layer depths simulated by an OGCM 总被引：1，自引：0，他引：1
The global distributions of the mixed layer depth h
D
, representing the depth of uniform density, and the mixing layer depth h
K
, representing the depth of active turbulent mixing, were simulated using an ocean general circulation model (OGCM), and compared
with each other, as well as with the mixed layer depth from the climatological data h
D
*. The comparison between h
D
and h
D
* suggested that the threshold density difference Δ σ
θ
should decrease from 0.09 kg m−3 to 0.02 kg m−3 with increasing latitude for consistent comparison between two mixed layer depths, due to the different nature of density
profiles depending on latitude. The comparison between h
D
and h
K
revealed that h
K
is deeper than h
D
in the region where strong subsurface shear is present, such as the equatorial ocean and the region of the western boundary
current. On the other hand, h
K
is shallower than h
D
in the high latitude ocean during convective cooling and early restratification. 相似文献