Tanning Industry

The tanning industry, crucial for processing animal hides into leather, generates highly specialized wastewater that contains a mixture of organic and inorganic contaminants. This industry’s wastewater treatment is essential to mitigate environmental impacts, such as pollution and habitat degradation, and to comply with stringent regulatory standards.

Specialized Wastewater Treatment Needs

Wastewater from the tanning process poses unique challenges due to:

• High Chemical Load: Includes tanning agents (both vegetable and synthetic), dyes, and fat-liquoring agents.
• Heavy Metals: Particularly chromium, which is used extensively in chrome tanning processes.
• Organic Matter: High levels of proteins, fats, and hair from raw hides that contribute to biochemical oxygen demand (BOD) and chemical oxygen demand (COD).
• Salts: Used in large quantities for curing and tanning, leading to increased salinity in wastewater.

Integration of Treatment Technologies

Managing the complex wastewater from tanning operations involves a series of integrated treatment stages:

• Preliminary Treatment: Screening and grit removal are used to eliminate solid wastes and particulates, preparing the wastewater for more detailed processing.
• Primary Treatment: Sedimentation techniques help remove settleable organic solids, reducing the overall load on subsequent treatment processes.
• Secondary Treatment: Biological treatment processes, typically involving aerobic digestion, are employed to significantly reduce BOD and COD by decomposing organic materials.
• Tertiary Treatment: Advanced treatment methods, including filtration and chemical precipitation, are used to remove residual contaminants, particularly heavy metals like chromium.
• Advanced Oxidation Processes (AOPs): Employed to break down persistent organic pollutants and further reduce the toxicity of the wastewater.