Advanced Materials Research Vol. 414

Abstract: The contaminated site remediation is an important content of site management. Plans for the introduction of measures and requirements to prevent and remediate soil contamination, particularly through the development of inventories of contaminated sites and the definition of targets for prioritization of remediation actions, are expected to have important consequences for site management practice and national site policies. Nowadays contaminated soil and groundwater treatment technologies can be sorted as three categories, that is bioremediation, chemical treatment and physical treatment. Biodegradation generally refers to the breakdown of organic compounds by living organism eventually resulting in the formation of carbon dioxide and water or methane. Chemical remediation is a kind of method that chemical reagent, chemical reaction and chemistry principles are used to reduce the mobility, organisms use ratio of heavy metals and decrease the heavy metals in the soil so as to remediate and repair the soil. Physical treatments in the remediation of contaminated site contains revising methods, capping methods, stabilization methods, electrokinetic methods and so on.

Abstract: On the basis of investigation of specific heavy metals contaminated site, use compound heavy metal hazard quotients to do a assessment for potential health risk. The primarily detected excessive heavy metals are Zn, Gr, Cu and Hg. Results indicate that: in the surface (0~30 cm) and subsurface (30~70 cm), the compound heavy metal hazard quotients of sampling point 7#, 12#, 13# 6#, 7#, 12#, and 13# are greater than 1, and soil exists heavy metal contamination; in 70cm~100cm soil layer, the hazard quotients of all monitoring points are less than 1, therefore in these layers soil is not contaminated, and there are no need for remediation. The result reflects compound heavy metal contamination directly, and provides a reference for later remediation work.

Abstract: The plutonium material within the nuclear devices would be aerosolized, released from the source-term and deposited in the soil after nuclear tests or accidents. Due to the natural and artificial disturbances the plutonium aerosols deposited in the soil would resuspend into the air. The hazard analysis of plutonium aerosol resuspension in typical dated nuclear-polluted regions is significative for radiation assessment and post-accident depuration in contaminated regions. The analysis shows that the soil eroding is the intrinsic factor of plutonium aerosol resuspension. The airborne contaminated concentration in non-nuclear source-term is much higher than nuclear source-term. The soil cleanup would lead to short-term rise of the airborne concentration. From the estimation of the equivalent dose, it is clear that the radiation hazards of the resuspended particulates in typical dated nuclear-polluted regions are extremely limited. After soil cleanup the annual effective doses of the contaminated regions are far below the radiation protection standards.

Abstract: Reaction conditions and spectroscopy properties of series hydroxyl-porphyrins for bonding with Pb²⁺ were described. A stable complex was formed with molar ratio 1:1 in the solution of N,N-dimethylformamide (DMF) with 0.6ml tween-80 as surfactant, when the pH was controlled at 6.5. The hydroxyl group on the benzene ring resulted in Soret band red shift of Pb-porphyrin complexes from 415.8 to 422.7nm, and isosbestic point of the axial coordination reaction appeared at 419.5nm. The study of thermodynamics predicted that the monohydroxyl-porphyrin had the optimal identification effects for Pb²⁺.

Abstract: In the remediation of heavy metal contaminated site, determining the remediation boundary of contaminated site and amount of contaminated soil are important link of the entire work. This paper uses surfer software to draw out a picture of Pb-contamination distribution in different soil layers, determines a remediation boundary, and provides a reliable basis and brings great convenience for later repair work.

Abstract: Under laboratory simulation experimental model, through adding exogenous chromium and CaCl₂ solution, we research adsorption, desorption characteristics of Cr in soils with or without fixative (zeolite). Research shows that: The soil with zeolite can increase adsorption capacity of soil for Cr, it can also reduce the desorption quantity of Cr. In thermodynamics experiment, Freundlich equation is one of the best model to describe adsorption、desorption characteristics for Cr in soil with or without zeolite.; In kinetics experiment, adding zeolite to soil could increase adsorption rate for Cr and decrease the desorption rate for Cr ,we could use Elovich equation to describe adsorption、desorption characteristics of soils with or without zeolite for Cr.

Abstract: This paper presents an examination of the current possession of electrical and electronic equipment (EEE) and predicted amount of waste electrical and electronic equipment (WEEE) in Chongqing. The results indicate that: the total EEE possession amount has reached a total of 287.73 million units in 2009; and the overall evaluated generation of WEEE from 2011 to 2015 would reach 13.53 million units, of which 19% are personal computers, 24% air conditioners, 7% refrigerators, 38% color TVs, and 12% washing machines, respectively. The recycling capacity is also investigated, evincing that about 952,000 waste units were recycled in 2009. There are three officially approved corporations for dismantling WEEE in 2010, with the dismantling capacity of 1,600,000 units per year. Moreover, several disposal facilities have been under construction and expect to be accomplished in 2015. This paper also proposes a number of recommendations aiming to improve the WEEE management system. For better management, it is necessary to arouse the public recognition of the need for formal processing of WEEE as well as to implement EPR approach, license system, and deposit-refund system.

Abstract: Select the former site of a chemical factory in Chongqing, China as the typical Cr contaminated site. According to “Technical guidelines for risk assessment of contaminated sites” and “Standard of Soil Quality Assessment for Exhibition Sites (Interim)” (HJ-350-2007), this paper conducts health risk assessment for the site, and provide a basis for contaminated soil remediation. At the same time, according to the contaminated condition, used the Golden Software Surfer 8 to draw the boundary of contaminated soils and thus calculate the volume of contaminated soil. By estimation the volume is about 3122.3 m³, which provide detailed data for the later remediation engineering.

Abstract: Petroleum contamination in soil has become one of the important contamination issues. Aiming at large areas petroleum contamination in soil, this paper introduce risk assessment and contamination quantitative calculation method. Based on risk assessment model and related quantitative calculation method, select a specific petroleum contaminated site, conduct risk assessment for it and then calculated the volume of contaminated soils. As a research case, the study can provide guidance to the preliminary investigation and a basis for effective remediation.