Monitoring Emergency Pollution Of Edible Water With Heavy Metals By Flow Injection Analysis

Emergency pollution of food water incidence is increasing and the safety of drink water face serious challege. Unknown sudden pollution of food water is one of the key research areas in the emergency management adminishered by governments. The purpose of this study was to investigate the possibility of the early warning of heavy metal such as lead, cadmium and mecury sudden pollution in food water, with the main content:(1) Evaluation of the correlation between the electric conductivity, pH value and heavy metal pollution; (2) Determination of Hg(Ⅱ), Pb(Ⅱ) and Cd(Ⅱ) with V. qinhaiensis by coupling flow injection-bioluminescence method; (3) Determination of Pb(Ⅱ) by flow injection analysis(FIA) spectrophotometry. (4) Determination of Cd(Ⅱ) in drinking water by FIA spectrophotometry using chemometrics-p matrix. The main results were as follows:(1) There were positive correlation between electric conductivity and the concentration of heavy metals, but the discrepancy wasn't significant when the concentration was below in 1000 times of the maximum levels for GB prescribled, except for Pb(Ⅱ).(2) An on-line FIA combined with luminescent instrument was set up to detect the metal ions via freshly prepared luminescent bacteria suspension (Vibro qinhaiensis sp.Q67 suspension were at the optimum cultivation pH of 6.75 for 17 h). Fit the luminescent inhibition-metal concentration line, it was indicated that 50% effective concentration (EC50) of Hg(Ⅱ), Pb(Ⅱ) and Cd(Ⅱ) were 0.57 mg/L,20.58 mg/L and 10.51 mg/L respectively. And the toxicity sequence from large to small was:Hg2+, Cd2+, Pb2+.(3) Based on the maximum absorption of the Pb(II)-xylenol orange (XO) complex was at 580 nm, determination of lead by using FIA with spectrophotometric was constructed. The results were showed that a solution 1.5×10-3mol/L XO in 0.02 mol/L acetate buffer (pH 5.0), in the presence of triton X-100 led to the sensitive color reaction of lead and XO, and it followed the beer's law in the concentration range of 2-10 mg/L with the LOD of 0.164 mg/L.(4) At the buffer solution (pH 9.0) of NH4Cl-NH3.H2O, the Zn2+, Cu2+, Cd2+were colored with 2-[(Bromo-2-pyridyl)-azo]-5-diethyl-aminophenol. Under the absorbent spectrum of 400-700 nm wavelength, the concentration of Cd(Ⅱ) was predicted with P-matrix model. The recoveries of Cu2+was approximately to 100%, and the Cd2+was 95.8-104.0% when Cu2+and Zn2+ were in low concentration.Rusults above concludes that combination of FIA, spectrophotometry and P-matrix model could detect the emergency pollution of heavy metals in the food water and alarm early this pollution on-line.