The field-scale stabilization remediation and assessment of potential toxic elements based on the multi-source information from a Chinese Pb/Zn smelter contaminated site

Potential toxic elements (PTEs) generally co-existing in soils make a great challenge to the sustainable development and utilization of smelter contaminated sites. This study delved into the pollution characteristics of PTEs and conducted the field-scale remediation of PTEs stabilization. The results indicated that Cd, Pb, Zn, and As were identified as the main PTEs pollutants in soils with exceedance rates of 75.80% for Cd, 76.43% for Pb and 88.54% for As, respectively. The distribution patterns of PTEs were closely associated with soil physicochemical properties, pollutant transport routes, hydrogeological conditions, formation lithology, smelting process and smelting workshop distribution. Soil PTEs mainly originated from smelting activities, such as the emissions of smelting wastewater, flue gas and slags. In addition, a combination of mixture agents and chelating agent (TJ400) showed excellent performance for the synchronous stabilization of Cd, Pb and As within 7 d, and the mixing degree between stabilization agents and contaminated soils was over 90%. The present results would offer practical guidance in developing a suitable remediation scheme based on a comprehensive investigation of the pollution characteristics of PTEs in soils.