【摘要】 痕量Zn,Cd,Pb,Cu离子的浓度在天山和青藏高原天然水中以及在东海海水中都是相似的。在淡水中的平均浓度分别为Zn 5.7,Cd 0.092,Pb 0.048,Cu 1.1 ppb。这证明天然水中痕量金属离子均匀分布规律是客观存在的。更多还原

【Abstract】 The concentrations of Zn, Cd, Pb, Cu ions are shown to foe similar in natural waters of Tianshan and Qinghai-Xizang (Tibet) plateau as well as in the sea. The metal speciation showed no significant changes throughout the natural water cycle.The average and variability of concentrations of trace metal ions in fresh water are respectively Zn2+ 5.7 ±26%, .Cd2+ 0.092±41%, Pb2+ 0.048±23%, and Cu2+ 1.1±18% ppb. The average concentrations in Bast China Sea water are Zn2+ 7.3 (5.5 in 1976), Cd2+ 0.12, Pb2+ 0.036, and Cu2+ 0.94 ppb.The phenomenon of a homogeneous distribution of trace metal ions in natural waters shows that the metal ions are carried in the water cycle. The rain water derives mainly from the evaporation of sea water; thus, the evaporation must carry trace metal ions from the sea into the air. The river water derives mainly from ram. water and runs into the sea. No significant equilibration transfer takes place between trace metal ions and particulate phases at the pH of natural waters.In the natural water cycle the trace metal ions are carried with the water. The transfer is not determined by the energy of the metal ions and, consequently, the thermodynamics do not present a problem. "When an ion occurs at trace concentrations the influence of the environment (the medium) will be of great importance, and the ion will not observe the rates of thermodynamic equilibrium theory. It may be concluded that the thermodynamic theory does not apply directly to physico-chemical processes at trace levels. In this case the free energy, G, can not be used directly to predict the feasibility of physico-chemical processes.更多还原