[Parameters optimization and cleaning efficiency evaluation of attrition scrubbing remediation of Pb-contaminated soil].

Attrition scrubbing was used to remediate lead contaminated-site soil, and the main purpose was to remove fine particles and lead contaminants from the surface of sand. The optimal parameters of attrition scrubbing were determined by orthogonal experiment, and three soil samples with different lead concentration were subjected to attrition scrubbing experiments. The results showed that the optimal scrubbing parameters were: a solid ratio of 70% dry matter, a temperature of 25 degrees C, an attrition time of 30 min, and an attrition speed of 1200 r x min(-1).

[Remediation efficiency of lead-contaminated soil at an industrial site by ultrasonic-assisted chemical extraction].

This research chose five lead-contaminated sites of a lead-acid battery factory to analyze the speciation distribution and concentration of lead. Under the same conditions (0.1 mol x L(-1) EDTA,30 min, 25 degrees C), the removal effect of heavy metal was compared between ultrasonic-assisted chemical extraction (UCE) and conventional chemical extraction ( CCE), and the variation of lead speciation was further explored.

[Analysis of washing efficiency and change in lead speciation in lead-contaminated soil of a battery factory].

Lead-contaminated soil with different pollution load in a lead battery factory in the southwest of China was chosen as the research object, the lead content and speciation were analyzed, and different washing agents were screened. The lead washing efficiency and lead speciation were analyzed under different pH conditions, and the soil of different particle size was washed using different duration to determine the best washing time. The results showed that the soil of sites A and B in the factory was severely contaminated, the lead concentration reaching 15,703.

[Distribution characteristics of lead in different particle size fractions of surface soil of a lead-acid battery factory contaminated site].

In this research, six topsoil samples (0-20 cm) were collected in the heavy-metal lead contaminated soil of one lead battery factory in south-west China as research object, which were later divided into seven particle size fractions, and analyzed for the lead concentration as well as the correlation between the lead concentration and the organic matter content. The result showed that five soil samples were contaminated with lead with different pollution levels, and there were two different trends in the changes of lead concentration as of the change of soil particle size. The lead concentration of the three samples from sewage treatment workshop, the workshop A and the workshop B, showed a first declining and then ascending trend with the decreasing particle size.

[Distribution characteristics and ecological risk of Pb in soils at a lead battery plant].

Soil samples were collected from 18 sites at a relocated lead accumulator factory in the Southwest region, China. Among the 15 sample sites, profile soil samples at 0-20 cm, 20-40 cm and 40-60 cm were taken. Soil lead contents were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES).

[Problems and countermeasures in the application of constructed wetlands].

Constructed wetlands as a wastewater eco-treatment technology are developed in recent decades. It combines sewage treatment with the eco-environment in an efficient way. It treats the sewage effectively, and meanwhile beautifies the environment, creates ecological landscape, and brings benefits to the environment and economics.

[Application of inverse distance weighted interpolation method in contaminated site assessment].

There are many difficulties in ascertaining the area that needs to be remedied in contaminated site. This paper integrated the experts' judgments with grids as the sampling strategy in an abandoned pesticide plant in northern China, and applied a geostatistical method, inverse distance weighted interpolation (IDW), to simulate the pollutants- and risk spatial distribution. Based on soil environmental benchmark, two scenarios were designed for ascertaining the polluted area.

[Ecological risk assessment and its research progress].

Ecological risk is a hotspot in the present environmental management study, which mainly focuses on the chemical, physical, and biological stressors that may damage ecosystem or its components. Ecological risk assessment (ERA) has a great significance for making scientific environmental management strategies. In order to lessen the damage of ecosystem or its parts, and to manage the ecosystem effectively, it is necessary to predict the probability the adverse ecological effects would occur and the consequences.