An approach to establish a soil environmental assessment model was proposed to evaluate the soil environmental quality level. The kriging technique and a self-organizing map (SOM) were integrated to investigate the soil environmental quality in a geographic information system (GIS). In this study, SOM was applied to categorize the data set of nine heavy metals in topsoil. A total of 261 topsoil samples were collected to determine the concentrations of Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, and Mn. The samples were clustered into three classes by SOM and visualized by GIS. The results show that different environmental quality categories are significantly different and that the soil environmental quality assessment model is effective.

Reactive dye BES golden yellow simulated wastewater was treated with H(2)O(2)-assisted photolysis method. Influences of factors such as reaction time, initial pH and H(2)O(2) dosage were investigated, and the reaction kinetics of the process were explored. Results showed that, the degradation of 200 mg/L BES golden yellow solution happened only in the presence of both conditions: UV irradiation and H(2)O(2) addition. Initial pH and H(2)O(2) dosage had remarkable influence on the removal efficiency of the dye. Through several groups of univariate experiments, the optimum pH and H(2)O(2) dosage of the photolysis process were found to be 6-7 and 0.0375 mL 30% H(2)O(2) per milligram of BES golden yellow, respectively. The photolysis process was approximately in accordance with the second-order kinetic equation.

Spatial distributions of soil Zn concentration in three horizontal soils in Guangdong, China, were surveyed and analyzed using geostatisitic and GIS. A total of 260 soil profiles data followed an approximately lognormal distribution. The Zn geometric mean concentration of 38.4 mg/kg in surface soils is higher than that in global soils. From A-to C-horizon Zn geometric mean concentrations had an increasing tendency of 38.4, 41.9 to 45.9 mg/kg. The ordinary kriging estimates of Zn concentration were mapped. It showed higher local concentration around big city and historical mining area. The soil Zn distribution was mainly dependent on bedrock properties. The anthropogenic impact is distinguished in local areas such as mining areas，where the Zn concentration is higher than their guide value. The results showed a strong gradient of stock of Zn around the mining area.