Iszap

Iszap is the Hungarian word for mud, sludge, or fine sediment and is used broadly in geology, environmental science and everyday language to describe wet, cohesive mixtures of water, silt, clay and organic matter. In technical contexts it corresponds to materials variously called sludge, slurry or sediment produced by natural processes (river and lake bottoms, wetlands) or by human activities (wastewater treatment, mining and industrial residue).

Composition and properties vary widely: iszap may be dominated by mineral particles, organic detritus, or industrial residues and can retain high moisture, exhibit low shear strength, and possess significant contaminant loads such as heavy metals, salts or organic pollutants. These characteristics influence environmental behavior, reuse potential and management needs.

Management and uses depend on source and contamination. Treated municipal sludge (biosolids) can be stabilized and used as soil amendment under regulatory controls; dewatering, digestion, composting, thermal treatment and landfilling are common handling options. Industrial iszap, including bauxite-derived "red mud" (vörösiszap), often requires specialized containment and neutralization because of corrosivity and toxic constituents; large accidental releases have demonstrated the serious risks of improper storage.

In everyday Hungarian usage, iszap is also applied metaphorically to mean muck or mess. The term’s technical significance makes it central to discussions of sediment management, wastewater treatment, reclamation and environmental risk mitigation.