Determining COD And Decolorating Mehthod For The Saline Water

Chemical Oxygen Demand (COD) is one of the important parameters in water monitoring. It is referred to the quantity of the consumed oxidant which is oxidized by the reductive matters present in the water and reckoned with the O2 (mg/L). At the same time, it is a reflection of the pollution degree of the wastewater contaminated by the organic substances. Generally, COD is determined with method of GB11904-89 for urban sewage, oil-field water, dyed waste water and so on. In recent years, with the comprehensive exploitation and utilization of the saline brine, much attention has been paid to the influence of the micro-amounts of organic substance on technical parameters of the products extracted from such brine. However, due to the high salinity and high concentrations of interference ions, especially Cl-, it is difficult to determine the COD by state standard method GB11914-89. So, determination method of COD has been discussed and some aspects improved in this paper.The products extracted from salt lake brine are colored more or less due to existence of the organic substances. Parameters influencing the determination of COD such as diluted times of brine, centrifugal time of the deposition, variety of the oxidants and so on were studied in this paper. Some kinds of resins, nanomembrane and ozone were used to decolor the brine, and the relevant conditions for treatment of brine by ozone were investigated especially. The resin was used in dealing with saline.the result was very well at pH=8. because the saline was diluted in test, the cost was increased. The concentration of ozone influenced on decoloring saline.Decoloring result was high along with the concentration of ozone increasing, the implement was installed in order to blister in increasing the concentration of ozone. The result was well at pH 2-6 and the temperature 40℃with ozone dealing with saline by the test.The membrane was the good method of dealing with saline。For membrane was not polluted and jammed, the saline was diluted. The good result was tested in P2 ? P5 4.