The Valence Atate Analysis Method And Conversion Law Of Iron In Hot Spring Water

Hot Spring used in our country has been existence more than4,000yesrs of history,and greatly enriched our life and our culture.However,the application of hot spring in our life and social has been minimal.In recent years,with the rapid development of national economic and social, spa tourism has developed into a new tourism theme.Bath Spa to experience the hot spring,hot spring culture theme of perception,leisure,health,holidays for the purpose of tourism activities are flourish.Meanwhile,the hot spring water in agriculture,aquaculture,geothermal power generation and the life of the eople also have a very wide range of applications.Therefore,hot spring in today’s society is playing an increasingly important role. The hot spring are high salinity water and rich in complex mineral composition.So far,there are no specifically analysis standards or specifications for hot spring water detection in China.The accuracy of mineral elements in the hot spring is a key effects in the process of preferably exploitation and utilization. It can provide effective information for the development and utilization of hot spring,to obtain the accurate analysis data of each element in the hot spring.The paper takes Sichuan ya’an zhougong mountain hot springs、Chengdu dayi county hydrosols bay hot spring and Chengdu Wenjiang yufu hot springs as the research target.This paper uses classic dinitrogen miscellaneous spectrophotometry and systematic research the valence state analysis method and distribution of valence state of iron in hot spring water for the first time. Summed up the hot spring water in the influence factors and characteristics of the iron valence con.Through the experimental results, evaluation of measurement uncertainty measurement results to analyze the influence of the main ingredients,to improve the quality of the determination results, evaluate the rationality of the calibration method.The conclusions are following:We measure the content of total iron and ferrous iron in hot spring water samples by spectrophotometric method.Getting distribution state of iron at the same time.The detection limit of the method was0.02mg/L,the precision (RSD) was1.61%, accuracy of total iron(the recover of standard addition)was98.42%to104.36%,accuracy of ferrous iron (the recover of standard addition) was95.25%to105.37%.The method meets the analysis requirements of valence state analysis of iron speciation in hot spring water,which has easy operation,low cost,high sensitivity and good accuracy.The iron is composed by Fe(Ⅱ)、Fe(Ⅲ) mainly,moreover minimal organic iron content is not analyzed in hot spring water.The pH, temperature, oxygen content of water samples are the major factors affectiong the iron valence in hot spring water.The paper detailedly argues the relationship of the pH value、the temperature、redox potential and placing time using to retrieve the hot spring water samples.Temperature of hot spring water decreases gradually with the growth of the placing time,and tending to room temperature.However redox potential increases with the increase of placing time.The change of the pH value is small.Experiment proved that there is interference for the determination of ferrous iron,when metal ion concentration of hot spring water samplesis,for example Cu2+, Co2+, Zn2+and Ni2+,is too large.But there is a way to effectively eliminate the interference of the metal ions the determination concentration of metal ions by adding an excess of naphthisodiazine.It demonstrates that added protection agents, storage time impact valence change of iron in hot spring water samples.Fe (Ⅱ) are slow oxidation of Fe (Ⅲ) with prolonged storage time in the original hot spring water samples.Fe (Ⅱ) can stored within seven days in sulfuric acid hot spring water samples, Fe (Ⅱ) is oxidized to Fe (Ⅲ) with the storage time extension, but the total iron content is almost unchanged.Because the Fe (Ⅲ) and naphthisodiazine formation of [Fe (phen)3]3+increases the ferrous iron absorbance,the determination results have larger error.Using NH4F masking Fe (Ⅲ) can eliminate interference, also had no effect on Fe (Ⅱ) and naphthisodiazine colorimetry.Taking Ya’an Zhougongshan hot spring water as an example.The process of the determination of iron in hot spring water uncertainly analyse and evaluation by naphthisodiazine spectrophotometric method.Finded out the main factors affecting of the uncertainty.To provide scientific basis for the quality control of laboratory and reasonableness test results.The measurement results of iron in water by naphthisodiazine spectrophotometric method is C=(0.359±0.0208) mg/L, at95%confidence level,while the coverage factor is2.