Current research situation and prospect of the complexation mechanism between dissolved organic matter and heavy metals in landfill leachate

The dissolved organic matter rich in landfill leachate contains hydroxyl, carboxyl, carbonyl and other active functional groups. It is an important carrier for the migration of heavy metals in environmental media. Due to different sources of landfill leachate, there are also significant differences in DOM component composition, types and contents of heavy metals. The common reaction between DOM and heavy metals is mainly complexation whicn is the key to affect the forms and environmental behavior of DOM and heavy metals in leachate. However, due to the complexity of DOM complexation process and in order to analyze the complexation effect, an effective characterization method and a complexation model based on it are important technical means to clarify the complexation mechanism between DOM and heavy metals in landfill leachate. The authors focused on the DOM characterization methods such as fluorescence technology, UV-Vis spectroscopy and infrared spectroscopy and common complexation models, and summarized the influencing factors such as pH, DOM composition and heavy metal ions in the complexation process, in order to provide theoretical guidance for pollution remediation technology and revealing the morphological transformation law of heavy metals in leachate .