微量元素
通常把海水中含量小于1mg/L的元素称为微量
元素。仅占海水总量的0.1％左右。 海水中除了14种元素（O、H、Cl、Ca、Mg、 S、K、Br、C、S、Sr、B、Si、F)浓度大于 1mg/L外，其余所有元素的浓度均低于此值， 因此可以把这些元素称为“微量元素”。 微量元素在海水中涉及的平衡有络合(螯合)、 氧化还原、生物吸收、颗粒物的吸附与解吸等。
R = River Input to Oceans (also Atm. and Interior) S = Sedimentation Rates
Residence Times of Some Elements in Seawater (My)
Element Na Mg Ca K Sr Si Li Rb Ba Al Mo Cu Ni Ag Pb
a) Measure of degree of Undersaturation. R = saturation conc./measured conc.
பைடு நூலகம்
Water samples must be collected in inert containers and isolated as they are recovered so as to prevent contamination.
Mn2+ < Fe2+ < Co2+ < Ni2+ < Cu2+ > Zn2+
Log KMX ___________________________________________
___
Ion Mn2+ Fe2+ Co2+ Ni2+ Cu2+ Zn2+ EDTA 14 14 16 18 19 16 Ethylenediamine 2.7 4.3 5.9 7.9 10.5 6.0 Nitrilotriacetic acid 7.4 8.3 10.5 11.4 12.8 10.5
PbCO3 Ni(OH)2 CoCO3 CuCO3 BaSO4 ZnCO3 CdOHCl CaCO3 SrCO3 MgCO3
Ra Sat Conc./Meas.
Years
10,000 - 20,000 2,000 10,000 - 225,000 18,000 50,000 - 400,000 18,000 133 - 266 50,000 3.7 84,000 120 - 250 180,000 40,000 - 10,000,000 500,000 0.25 - 1.2 8,000,000 2.75 190,000,000 27 450,000,000
d10 Cations
Transition Metals
Electronic Configuration of Atom
Period Z 1 1 2 2 3 4 5 6 7 8 9 10
K __ Element s H 1 He 2
Li Be B C N O F Ne 2 2 2 2 2 2 2 2
Trace Elements
Trace elements occur in minute quantities and are usually measured in parts per billion (ppb). -even in small quantities they can be important for either promoting or killing life.
Goldberg's Classification of Metals
do Cations Metals with rare gas configuration Na+, Mg2+, Ca2+, K+
Metals with 18 outer electrons Ag+, Zn2+, Ga3+, Ge4+ Metals between d0 and d10 Mn2+, Fe2+, Co2+, Ni2+, Cu2+
The
Niskin bottle has valves at each end which are automatically closed when a weight, called a messenger, is sent down the cable and causes the bottle to flip over and seal itself. Sample depth can be determined from cable inclination and length or with a pulsating sound source.
Concentration [ppb]
170 60 10 10 10 10 3 2 0.1 0.03 0.03 0.004
微量元素的来源
陆地径流 海底火山活动
大气尘埃降落夹带的微量元素——大气
输入 沥滤岩石 人类活动
微量元素的特点
非保守性（地球化学活性较大；生物活 性大；区域性变化大） 含量低 微量元素循环及迁移转化复杂（水动力 迁移；化学过程；生物迁移） 研究难度大（测定方法限制；采水器； 样品贮存；分析方法检出限）
1. Conservative Profiles
Trace element
Lithium (Li) Iodine (I) Molybdenum (Mo) Zinc (Zn) Iron (Fe) Aluminum (Al) Copper (Cu) Manganese (Mn) Cobalt (Co) Lead (Pb) Mercury (Hg) Gold (Au)
生物过程 吸附过程
海—气交换过程
热液过程 海水—沉积物界面交换过程等。
Broecker's Classification
Unlimited: All Major except Ca, C and Si Biolimited: N, Si, and P (Fe) Intermediate: O, Ca, C, Sr, Ba, Ra, Se and most minor elements
Distribution of Elements in the Oceans
1. 2. 3. 4. 5.
6.
7.
Conservative Profiles Nutrient Type Profiles Surface Enrichment and Depletion at Depth Mid-Depth Minima Mid-Depth Maxima Mid-Depth Maxima or Minima in the sub-oxic layer Anoxic Waters
4. 海水中微量元素
本章要点：
海水中微量元素的含量、分布和存在形式 微量元素在海洋中的化学过程、生物过程、
再循环模型
海水中微量元素的含量和分布
周期表中14种元素的浓度超过1mg/L :
O, H, Cl, Na, K, Mg, S, Ca, Br, C, Sr, B, Si, F 其中活性元素： Si
River Input 210 22 1 10 10 0.935 12 6.1 0.05 0.0031 2.15 0.043 0.015 0.25 0.00056
Sedimentation 260 45 8 11 19 0.01 19 0.27 0.084 0.0001 0.5 0.05 0.018 2.1 0.002
L _______ s p
M _____________ s p d
N ______ s p
1 2 2 2 2 2 2 2
1 2 3 4 5 6
K __ Period Z Element s 3 11 Na 2 12 Mg 2 13 Al 2 14 Si 2 15 P 2 16 S 2 17 Cl 2 18 Ar 2 4 19 20 21 22 23 24 25 26 27 28 29 30 31 32 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge 2 2 2 2 2 2 2 2 2 2 2 2 2 2
Ion Be2+ Mg2+ Ca2+ Sr2+ Ba2+
Log KMF 4.29 1.82 1.04 0.45
d10 Cations（阳离子）
单价d10金属阳离子与d0金属完全不同，和卤素能形 成强络和物 随着原子量或配位体体积的增加，稳定性增加。

M + L
Complex AgL CuL
Comparison of Ratio of Saturated Concentration to Measured Values and Residence Times
Metal
Pb2+ Ni2+ Co2+ Cu2+ Ba2+ Zn2+ Cd2+ Ca2+ Sr2+ Mg2+
Insoluble Compound
(Strength Z/r where Z is the Charge and r is the Radius) M + L ML KML = [ML]/[M][L] Log KMOH 10.28 2.3 1.4 0.9 0.8 Radius 0.31 Å 0.65 0.99 1.13 1.35
1、反应活跃，快速转移到沉积物中 (Al3+)
2、源头浓度低 (Cs+)
= Concentration in Ocean/Amount Supplied dA/dt = R - S = 0 Steady State Condition S = k [A] = 1/k = [A]/R = [A]/S