From Pollution to Purification: Behavior and Fate of Heavy Metals in the Water Environment

Dear Colleagues,

This Special Issue aims to advance a source-to-solution understanding of heavy metals in aquatic systems by linking (i) the processes that control their behavior and fate with (ii) evidence-based purification and risk-reduction strategies. The overall focus is on how heavy metals are introduced, transported, transformed, stored, remobilized, and ultimately removed (or persist) across the water–sediment–biota continuum in diverse water environments, including rivers, lakes, reservoirs, estuaries/coastal waters, groundwater, urban waters, and wastewater-impacted systems. The scope explicitly covers both “classic” toxic metals/metalloids (e.g., As, Cd, Cr, Hg, Pb, Ni) and increasingly relevant critical/strategic metals (e.g., Co, Li, rare metals associated with mining, e-waste, and energy transitions), particularly where they co-occur and interact.

The Special Issue will feature studies that elucidate key mechanistic controls on metal fate, including speciation and bioavailability, redox transformations, complexation with dissolved organic matter, adsorption/desorption on mineral surfaces, colloid- and particle-facilitated transport, sediment–water exchange under hydrodynamic disturbance, and biologically mediated processes. We particularly encourage contributions addressing multi-stressor interactions—for example, how eutrophication, salinity gradients, wet–dry alternation, climate-driven extremes, microplastics/colloids, or engineered nanomaterials modify metal mobility, toxicity, and treatability.

On the “purification” side, the Special Issue emphasizes actionable remediation and treatment grounded in mechanistic insight, spanning in situ stabilization/capping, reactive media (e.g., Fe-based amendments, biochar, and mineral sorbents), constructed wetlands and nature-based solutions, bioremediation and phytoremediation, electrochemical/advanced oxidation approaches where relevant, and membrane or hybrid processes for complex wastewaters. Contributions that integrate monitoring, modeling, and decision support are welcome, including isotopic tracing, passive samplers, high-resolution spectroscopic/omics characterization, coupled hydrodynamic–biogeochemical models, and data-driven approaches (e.g., machine learning) for prediction, early warning, and scenario assessment.

Positioning within the existing literature: The field has produced extensive knowledge on metal contamination, speciation, and remediation, yet much of the literature remains fragmented—often separated by discipline (geochemistry vs. engineering), compartment (water column vs. sediment), scale (lab vs. field), or single-metal focus. Meanwhile, real-world systems increasingly present mixtures, dynamic boundary conditions, and co-contaminants that challenge both mechanistic interpretation and technology transfer. This Special Issue is situated to bridge these gaps by consolidating the latest advances into a coherent framework that connects pollution sources and mechanistic fate to technology performance and risk outcomes, thereby supporting robust monitoring strategies, more predictable treatment design, and science-informed management for aquatic environmental quality improvement.

Prof. Dr. Zhibin Zhang
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• heavy metals
• speciation
• bioavailability
• sediment–water interface
• redox processes
• DOM complexation
• transport modeling
• passive sampling
• nature-based solutions
• reactive amendments
• risk assessment
• bioremediation technology