[Assessment and Pollution Characteristics of Heavy Metals in Soil of Different Functional Areas in Luoyang].

The residential areas, science and education areas, urban green lands, commercial districts, urban arterial roads, industrial zones and urban and rural junction districts in seven different functional zones of Luoyang City were taken as research subjects, and sixty-three soil samples were gathered. The concentrations of soil heavy metals were measured and their pollution levels were evaluated by single pollution index and Nemerow complex pollution indices. The ecological risks of soil heavy metals were discussed with Hakanson potential ecological risk index (RI) and their geneses and sources were indicated by the principal component analysis (PCA). The results showed that the average level of all heavy metals exceeded the background values of Henan Province. The pollution degree of single gene index was in the following order:Cd> Zn> Pb> Cu> Ni> Cr. Nemerow complex pollution indices indicated heavy metals had the highest concentration and the heaviest pollution in industrial zones. A single heavy metal potential ecological harm (Eri) showed Cd had the highest risk index. RI was ranked as industrial zones> urban arterial roads> commercial districts> residential areas> science and education areas> urban green lands> rural junction districts. The heavy metal pollution in industrial zones, urban arterial roads and commercial districts reached strong levels, and the pollution in residential areas, science and education areas, urban green lands reached moderate risk levels, but that in rural junction districts belonged to slight risk level. Cu, Zn, Pb and Cd were called anthropogenic factors and came from industrial wastes and transport emissions, but Cr and Ni were explained as natural factors and their contents depended upon the parent materials of soil.

[Anolyte enhanced electrokinetic remediation of fluorine-contaminated soils].

An experimental study was carried out in order to determine the characteristics of migration and its influencing factor of soil fluorine in the electrokinetic process under different applied voltage and concentration of anolyte. The feasibility of anolyte enhanced on electrokinetic remediation of fluorine-contaminated soil was analyzed. The results show that when deionized water is used as anolyte with the 1.0 V/cm voltage gradient, the cumulative mass of fluorine in catholyte and anolyte are 8.2 mg and 47.7 mg respectively and the removal rate of fluorine is only 8.8%. Anolyte enhanced electrokinetic process can promote effectively the migration of fluoride in soil. When 0.02 mol/L NaOH solutionis employed as the anolyte, the removal rates are 25.9%, 31.2% and 47.3% with 1.0, 1.5 and 2.0 V/cm voltage gradient respectively. As the concentration of anolyte increased to 0.1 mol/L, the removal rates are 55.4%, 61.1% and 73.0%. The electromigration is the main transport mechanism and the electroosmotic flow has an effect on the migration of fluorine in soil. The voltage gradient and the concentration of anolyte are the main factors influencing the removal rate of fluorine in soil. Appropriate anolyte enhanced electrokinetic method can be applied to remediate fluorine from contaminated soil.

[The effect of crystallization of calcium carbonate on the secondary structure of pepsin].

The effect of crystallization of calcium carbonate on the secondary structure of pepsin was studied by Fourier transform infrared spectroscopy, derivative, deconvolution and curve-fitting techniques in this paper. The result shows that the pure protein is composed of 24.38% alpha-helices, 29.91% beta-sheets, 39.22% beta-turns and 6.49% random structures, and the pepsin in the CaCO3/pepsin solution is composed of 2.09% alpha-helices, 93.304% beta-sheets, 4.60% beta-turns and 0.006% random structures. From these data we can see that the alpha-helices decrease and the beta-turns increase with the formation of the crystal of calcium carbonate. The essence of these changes is discussed in the paper.