Xiao Nan Sun

Health Risk Assessment and Quantitative Calculation of Typical Cr Contaminated Sites

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.

The Application of XRF in Field Monitoring on Digging Pb-Contaminated Soil

In this paper, a portable X-ray fluorescence (XRF) is designed to monitor the digging process of Pb contaminated soil based on contaminated site remediation. This field monitoring method is applied to the project of Pb contaminated restoration site K. A full time program is designed for XRF to monitor the exceeded standard regions of Pb pollution during the digging contaminated soil. The acceptance monitoring results show that the Pb concentration of all original exceeded points are under the limit value 260mg/kg, and reach the requirement of environmental protection. This application results show that the portable XRF was designed effectively in field monitoring on heavy metal such as Pb, which realize the purpose of quickly identification and digging of contaminated soil.

The Discrimination and Disposal of the Cover of Contaminated Sites

This paper discussed the discrimination and disposal of pollution in the cover of contaminated sites. A discriminating and disposal solution for the cover of contaminated sites aim at the key situation that there is much pollution risk in the cover of contaminated site as well as the soil owing to industry enterprises’ transfer. Through sampling analysis and comprehensive risk assessment, we obtained the risk of contamination and its distribution in the cover of contaminated sites, then cleaned and transported them according to the risk category. The results of experiments show that this solution can effectively control the contamination risk during the disposal progress, and avoid the metastatic spread of the contaminated soil.

Study on the Relationship between Contamination Distribution and Sampling Density

Use some contaminated site (D-block) in Chongqing of China as the experiment site, this paper studies effects of different sampling density (layout grid spacing) on the contaminated area and determination of contaminated boundary in system layout method of environmental monitoring, and then discusses the relationship between sampling density and contaminated distribution in system layout method according to the experiment result. The experiment result indicates that: in a certain range, increase the sampling density, contamination distribution will be more accurate; too big sampling density is not practical; for the common sites with unknown or large-range contaminated distribution, 10m×10m is the recommended layout sampling density.

Study of Migration of Different Petroleum Hydrocarbon Contaminated Components in Soil

This paper is about the migration of the total petroleum hydrocarbon (TPH) contamination, which concludes the migration rule of the TPH contamination through designing indoor soil column leaching experiment. Through researching the migration concentration of different components of TPH, experiment concludes that different components have different relative transfer abilities in typical soil, and the transfer ability has an inverse relation to the molecular weight and the ring numbers of aromatic hydrocarbon. The purpose of this research is to provide guidance to nonproliferation and remediation of the petroleum contamination.

Research on the Migration of Petroleum Hydrocarbon Contamination in the Soil in Different Leaching Amount

This paper discusses the migration of the total petroleum hydrocarbon (TPH) contamination, which concludes the migration rule of the TPH contamination through designing indoor soil column leaching experiments. Through researching the migration concentration of TPH in different leaching amount, results shows that the ability of migration of TPH is more powerful when there is more leaching amount. But overall, the affection caused by different leaching amount is not obvious. The results of this research can provide guidance to the nonproliferation and remediation of petroleum contamination.

The Study of Remediation Standards of Heavy Metal-Cu Contaminated Soil Based on Risk Assessment

This paper describes the model of heavy metal-Cu contaminated soil remediation standard value based on risk assessment. In the Cu contamination risk assessment model, the main exposure methods are oral ingestion and inhalation through breathing, which not only simplifies the calculation but also make people get a clearer understanding of the way of Cu contamination. We get the simplified formula, calculate and discuss Cu contaminated soil remediation target value in specific parameters to provide reference and basis for the remediation of Cu contaminated soil.

Calculation of Remediation Cut-Off Value of Pb-Contaminated Sites Based on the Health Risk

This paper conclude and determine the range of key parameters based on the effects of heavy metal Pb to Human blood-Pb health risk. According to Chinas reality, Pb levels in air, drinking water are 0.122~1.0 ug/m and 2~10ug/L; ingestion of Pb from food by children of 0~6 years old is 10~25ug/d. Pb cut-off value for residential land soil are calculated with the Integration Exposure Uptake Biokinetic Model (IEUBK). The result shows the Pb cut-off value for residual land is 294.5mg/kg. The result provides a reference for cut-off value of Content of lead in soil, and brings convenience for the research and practice of remediation Pb contamination in soil.

Quantitative Evaluation of a Typical Petroleum Hydrocarbon Contaminated Site

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.

The Remedial Effect of the Decomposing Bacteria on Different Petroleum Hydrocarbon Contamination

Petroleum contamination has become one of the major soil contaminations. Aiming at petroleum hydrocarbon contamination, the multi-group opposite experiments is set; this paper use some petroleum hydrocarbon-decomposing bacteria to remedy the soil contaminated by different carbon chain petroleum hydrocarbons. Compare and study the remedial results, and study the growth of the bacteria in the decomposing process. The Study shows that the degradation rate of the bacteria to short-chain petroleum hydrocarbons is relatively high; Within 40 days without nutrient substance, degradation rate of bacteria to gasoline and diesel is 80%, degradation rate of bacteria to aromatics and lubricants is 50%, the trend of bacteria’s growth curve and the degradation rate curve of each component are approximate.