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Soil remediation technology screening is an important procedure in the supervision of contaminated sites. The efficiency and costs of contaminated site remediation will be directly affected by the applicability of soil remediation technology. The influencing factors include characteristics of contaminants, site conditions, remediation time and costs should be considered to determine the most applicable remediation technology. The remediation technology screening was commonly evaluated by the experienced expert in China, which limited the promotion and application of the decision making method. Based on the supervision requirements of contaminated sites and the research status at home and abroad, the screening method includes preliminary screening and explicit evaluation was suggested in this paper. The screening index system was constructed, and the extension theory was used to divide the technology grade. The extension theory could solve the problem of human interference in the evaluation process and index value assignment. A chromium residue contaminated site in China was selected as the study area, and the applicable remediation technologies were suggested by the screening method. The research results could provide a scientific and technological support for the supervision and management of contaminated sites in China.

Groundwater is the main source of water supply in China, and China's overall situation of groundwater pollution is not optimistic at present. Groundwater pollution risk evaluation and early-warning are the effective measures to prevent groundwater pollution. At present, research of groundwater early-warning method at home and abroad is still at the exploratory stage, and the sophisticated technology has not been developed for reference. This paper briefly described the data and technological demand of the early-warning method in different scales, and the main factors influencing the early-warning results of groundwater pollution were classified as protection performance of geological medium, characteristics of pollution sources, groundwater dynamics and groundwater value. Then the main early-warning indexes of groundwater pollution were screened to establish the early-warning model of regional or watershed scale by the index overlay method. At last, the established early-warning model was used in Baotou plain, and the different early-warning grades were zoned by the model. The research results could provide scientific support for the local management department to protect the groundwater resources.

Since the 1990s, most developed countries have issued the risk-based environmental standards or criteria for soil, as well as corresponding technical background documents, this provides methodological references for developing soil environmental standards and criteria in developing countries. However, because of the variability in legislation frameworks, derivation procedures of criteria, environmental conditions and climates, soil types, and habits and customs among countries, there are great differences in the names, roles and values of soil standards and criteria. This paper presents the scientific basis and fundamental features of soil environmental criteria. The definitions, functions and values of the soil environmental criteria in different countries were compared and analyzed. Key technologies for the development of soil environmental criteria and critical influence factors were summarized and analyzed, with special respect to the classification of land use types, setting of exposure scenarios and pathways, selection of acceptable risk levels for carcinogens, and the determination of exposure parameters. Strategies and countermeasures for the development of local or regional soil environmental criteria in China were proposed by referring to international experiences, and the current difficulties and challenges faced by China in the development of soil environmental criteria were discussed and addressed.