The Research Of Chemical Characters Of The Underground Brine Along Laizhou Bay

This paper has a systematic description on the origin. cause of formation and chemical characters of the underground brine along Laizhou Bay. The main content and conclusion are as followed:1. The analytical results of the underground brine samples indicate that there is a relationship between brine and seawater.The ratios of rNaVrCl" and Cl~/Br~ suggest that brine comes from seawater.2. Basede on Herut' s experimental data and MacCffrey' s experimental data, we calculate the ratios of NaVCl- and Ca2+/Mg2+of the underground brine. The results suggest that brine format through evaporateion but not freezing.3. There are a series of physical and chemical reactions such as evaporation, ion-exchange, erosion of mineral etc .which influence the concentration of major content in brine .With the precipitation of CaS04 and the reduction of S042-, the concentration of SO42-decreases. The concentration of C03 2 is mainly influenced with the precipitation of CaC03.4. Ion-exchange is the most important reaction to the concentration of cations. K\ Na\ Mg2+ in the brine can exchange with Ca2+ of the clay mineral. The reaction makes K\ Na\ Mg2+ decreasing, but Ca2+ increase in the brine. Erosion of mineral can release Na+ and Mg2+. Therefore except If the other cations are affected by two or more reactions. The exchange of K+between seawater and clay is an important transport form of K+ from the seawater.5. Brine is a reductive environment. The concentration of Iron andManganese is about 2~4 order of magnitude higher than those in the seawater, the low pH and reductive environment contribute to the production of FeJ' and Mn2+, In addition, the variation of the ratio of Mn"'VFe""is also discussed. Analytical result of the nutrient concentration of the sample revealed that NH4+ is the primary form of DIN, which may be due to the decomposition of organic matter, reducetion from N0n\ N02~ and exchangeable reaction on the surface of the mineral.6. The concentration of dissolved Uranium is between 33.04 and 97.92 ug/l.The high concentration may be due to the dissolution of the particular Uranium which can reflect the alteration of redox environment of the brine.