A Study For A Method Of Using Thin Film Technique To Determine Sulfide And Fe²⁺ In Sediment Determine

With the development of science and technology, it was found in the area ofenvironmental monitoring that traditional sampling methods inevitably lead tothe occurrence of certain changes of the physical, chemical, and biologicalduring sample storage. It often leads to fails of the samples, so scientists havebeen actively exploring new sampling technique. Thin-film diffusion techniqueis a new method developed in recent years. It can be directly collect targetmonitoring materials without affecting the maternal concentration and thesurrounding environment. It uses collection of environmental pollutanttechniques in situ and quantitative method. In this present study the improvedDGT technique was specifically applied to the determination to sulfides insediment. And it combines the DET technique to sample and detect sulfide, Fe²⁺and P in sediment in the same time. Main conclusions are drawn as follows:1. When improved DGT film applied to the determination to sulfides insediment, it can reach adsorption saturation in24h, and the maximum adsorptioncapacity is1000mg/L. And all adsorption rates reached100%±1.2. Developed models based on the grey intensity in the scanned picture ofDGT film and concentration of sulfide purged and trapped from DGT film.Y=30.918ln(X)－72.333. According to this model formula, it can get the actualconcentration of sulfide in sediment by directly scanning DGT film.3. Compared absorption rates to Fe²⁺and P of three DET gel films (0.4mm,0.8mm,1.18mm) with different thickness, it was found that adsorption effect ofthe0.8mm gel film is best,1.18mm was the second,0.4mm had little effect.4. DET and DGT were combined to simultaneously determine the contentsof sulfide, Fe(2+)and P in sediment in Xuanwu Lake. The contents of sulfide wasless than900nmol/L, Fe²⁺was10to40mg/L, P was less than2.5mg/L in winter2011.