Study On The Atomization Kinetics Of Chromium In Graphite Furnace And The Eco-Behavior Of Chromium In The Environment

A new kinetic model for graphite furnace atomic absorption signal has been developed. The apparent energy of atomization for chromium and kinetic parameter along with the effect of the interference elements on the tip time and were investigated. The results show that the apparent energy of atomization for chromium is positively related with the vapor heat of the interference elements.Three new flow injection manifolds were designed for the speciation analysis of chromium in the environmental waters using derivative-flame atomic absorption spectrometry.The behavior of adsorption and the effect of acid rain on both chromium (III) and chromium (VI) in soil were investigated. The results indicate that the characteristics of adsorption isotherms correspond well with the Langmuir equations. The concentration and the mass of chromium eluented with acid rain as desorption agent are related to volume of acid rain, and can be expressed as the equation ofC = ae-kH and q = q e-c/V , respectively.The Eco-behavior of chromium-contaminated water and soil on edible plants was studied using statistical methods. The results show that toxic effects of both Cr3+ and Cr6+ on seeds germination and root elongation of radish (Raphanus sativus) are positively related with the contents of chromium in soil and water. A EC50 of chromium concentration-effect curve is related to the speciation of chromium and the breed of radish. For the De-Ri No. 2 radish seed, the EC50 of Cr6+ and Cr3+ on inhibition of root elongation are 65.84 mg/L and 128.35 mg/L, 1.5-fold and 2-fold than that of Chun-Xue radish seed, respectively; The toxic effect of Cr6+ -contaminated soil is 61 times than that of Cr3+-contaminated. The inhibition effect ofradish root elongation in Cr6+ -contaminated soil is 2-fold higher than in Cr3+-contaminated water, but the toxicity on root elongation inhibition in Cr3+-contaminated soil is 14-fold lower than in Cr3+-contaminated water. The results obtained from this study show that the inhibition index of root elongation is more sensitive than the inhibition index of hypocotyl growth for evaluating potential phytotoxicity. There is the negative correlation between biomass and chromium content in soil. When the content of Cr3+and Cr6+ added to soil was 2807.4mg/kg and 31 .0mg/kg, respectively, the yield reduced 50%. The accumulation of Cr3+ and Cr6+ in seeds body is evidently different with soil character. Cr6+ in soil are higher toxicity and bioactivity.