[Urban industrial contaminated sites: a new issue in the field of environmental remediation in China].

Contamination of urban industrial lands is a new environmental problem in China during the process of upgrade of industrial structure and adjustment of urban layout. It restricts the safe re-use of urban land resources, and threatens the health of surrounding inhabitants. In the paper, the market potential of contaminated-site remediation was known through analysis of spatial distribution of urban industrial sites in China. Remediation technologies in the Occident which were suitable for urban industrial contaminated sites were discussed and compared to evaluate their superiority and inferiority. And then, some advices of remediation technologies for urban industrial contaminated sites in China were proposed.

[Chemical oxidants for remediation of soils contaminated with polycyclic aromatic hydrocarbons at a coking site].

Different oxidants were evaluated for removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils at industrial coking sites with the use of simulating device, and the fate of pollutants during the treatment was investigated. Permanganate showed the highest PAHs removal rate (96.2%) of the oxidants studied. Most of the PAHs were oxidized and only < 1% of PAHs volatilized and transferred to the solvent. The removal of PAHs by activated persulfate reached 92%. Modified Fenton reagent could remove 80% of PAHs, and < 2% of PAHs volatilized and transferred to the solvent after treatment with activated persulfate and modified Fenton reagent. The efficiencies of hydrogen dioxide and Fenton reagent for removal of PAHs were both < 60% ,and up to 6% of PAHs volatilized and transferred to the solvent. In summary, permanganate and activated persulfate are the most effective and environment-friendly oxidants for removing PAHs from contaminated soils. The chemical oxidants could easily remove ANY, ANT, BaP, DahA, BghiP and IcdP, but FLE, CHR and Fla were relatively resistant to chemical oxidation.

[Preliminary study on the association of lanthanum and phosphorous loss from soil].

Through laboratory lysimeter experiments and artificial rainfall experiments, characteristics of P and La transportation from both vertical and horizontal directions are investigated. The association between La and P loss from soil is preliminarily discussed. Results of lysimeter experiment show that both La and P are difficult to transport vertically. Downward depths are no deeper than 6-8 cm for all forms of La and P. With the increasement of exogenous La amount, the amount of Water soluble P, NaHCO3-extractable P and NaOH-extractable P decrease, while HCl-extractable P and residual form of P increase. Results of artificial rainfall experiment show that majority of La and P transport with fine soil particles in runoff, which is more than 95%. Loss of total P and La in runoff from the manure-applied soil are correlated significantly, both in loss rate and loss amount.

[Comparison of characteristics of heavy metals in different grain sizes of intertidalite sediment by using grid sampling method].

384 surface sediment samples were collected from mud flat, silt flat and mud-silt flat of Bohai Bay by 1 m and 10 m interval using grid sampling method. Concentrations of Al, Fe, Ti, Mn, Ba, Sr, Zn, Cr, Ni and Cu in each sample were measured by ICP-AES. To figure out the random distribution and concentration characteristics of these heavy metals, concentration of them were compared between districts with different grain size. The results show that varieties of grain size cause the remarkable difference in the concentration of heavy metals. Total concentration of heavy metals are 147.37 g x kg(-1), 98.68 g x kg(-1) and 94.27 g x kg(-1) in mud flat, mud-silt flat and silt flat respectively. Majority of heavy metals inclines to concentrate in fine grained mud, while Ba and Sr have a tendency to concentrate in coast grained silt which contains more K2O * Al2O3 * 6SiO2. Concentration of Sr is affected significantly by the grain size, while concentration of Cr and Ti are affected a little by the grain size.