Scientific definition of hazardous wastes containing heavy metals and their resource utilization
Baoping Xin1*，Jia Wang2
1. School of Material Science and Engineering, Beijing Institute of Technology， Beijing 100081, China;
2. School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Abstract:
In recent years hazardous wastes (HWs) as highly harmful solid waste have been drawing increasing attentions due to their serious environmental pollution and severe threat to health. Because HWs are characterized by huge production, very wide range, numerous sources, and very complicated components and structure, a scientific classification and grading is necessary to both their refined management and precise treatment and the system construction and healthy development of HWs discipline. Among HWs, there is a fairly large category with toxic characteristics originated from the toxicity of heavy metals contained. The large class of HWs has long-term harm to both environment and health due to undegradability of the toxic heavy metals, whilst the big category also displays irreplaceable resource value owing to irreproducibility of the heavy metals. In the current work, the big category as an important and unique subdivision area of HWs was scientifically defined in the world for the first time, with clear intension and extension; metals/heavy metals was reclassified into five category, covering expensive metals, high-price metals, low-price metals, high toxic metals and non-toxic metals, and the feasible route for resource utilization of the HWs containing heavy metals was proposed; the applicability of pyrometallurgy, hydrometallurgy and bioleaching was fully analyzed in the extraction and recovery of metals from the HWs containing heavy metals, and two leading appeals and technical principle of resource utilization of the HWs containing heavy metals was also discussed.