Detection Of Heavy Metal Content By The Method Of Raman Spectrometry In The Plant And The Water

Heavy metals are solid in front of us in our daily lives. When heavy metals turned intowaste gas, waste water and waste emission, they could really do harm to our health. The wastegas, waste water and waste emission stuff into the air and absorbed by plants. People ingestthem through four big ways, such as food water atmosphere and skin contact. It’s on theurgent to seek a kind of rapid separation detection method of heavy metals. This paper fullyused by Raman spectroscopy to detect heavy metal content. The test applied resin absorptionand co-precipitation method to separate heavy metals in the plant and the water. At the sametime, the test combining of Raman spectroscopy to have indirect detection. The papers do asfollows:(1) Preprocessing resin by HCl and NaOH, the research conducted several times.Comparing different types of resin adsorption rate of heavy metal copper and lead, choosingthe ion exchange resin D113to absorb copper and chelating resin D401to absorb lead, alsoutilizing oscillation time of two kinds of resin, solution pH, solution temperature to discussedthe adsorption effects of heavy metal copper and lead, the best adsorption conditions weredetermined. The research shows: changing the solution temperature of D113had a littlefunction on resin adsorption rate. Experiments of copper to be carried out at the condition ofroom temperature, pH from5-7, it shows that the best oscillation time of D113is80min andoscillation speed is120r/min. Experiments of lead to be carried out at the condition of25centigrade, pH at6at about, it shows that the best oscillation time of D401is80min andoscillation speed is120r/min.(2) Taking cleaning, drying and crushing vetiver as experimental subjects for resinadsorption, after the adsorption of heavy metal, the Raman spectra of resin used differentpretreatment for processing and selected the optimal PLS pretreatment model. The results ofthe study shows that: in the experimental group of D113resin adsorption of copper, After thepretreatment of first order differential (3points), copper content detection model works bestin resin D113.It shows that interactive correlation coefficient is0.78and RMSECP is thepercent of23.46%.After the pretreatment of first order differential (3points), copper contentdetection model works best In D401resin absorption of lead in the experimental group. Itmanifested that external interactive correlation coefficient is0.727and RMSECP is thepercent of7.275%.(3) The Mn2+-Dipy-SCN-ternary complex system was applied to complexation precipitation for the heavy metal cadmium ion in the water. After drying sediment andcollecting Raman spectroscopy, correction model for acquisition of Raman spectra and heavymetal content is set up respectively. According to the research, the models of the heavy metalcadmium complexation of Raman spectra gone through the method of first derivative,baseline correction, trend algorithm and second order differential pretreatment are preferable.External validation of the correlation coefficient and RMSEP of prediction set is0.9and0.0108respectively in copper group. Also, External validation of the correlation coefficientand RMSEP of prediction set is0.9156and0.0119respectively in chromium group.