Tin-Smelting Wastewater Treatment
Background
Tin smelting wastewater is produced by tin smelting plants as a result of metal processing and products. Tin smelting wastewater contains a large amount of metal ions such as Sn2+, Pb2+, Zn2+, Cu2+, and sulfide ions such as HS-. It also includes reducing agent, oxidants and some other organic matters. If not treated properly, those metal in the wastewater will accumulate in aquatic systems and bring water pollution problems.
Characteristics of Tin-Smelting Wastewater
Tin-smelting wastewater contains a high amount of sulfur, iron, aluminum, and calcium. The pH should be checked before treatment and it is usually 7.5-8.5. Its ratio of COD and SS should be around 1.5-2.5 and its color of the water should be between gray and yellow. A large amount of dissolved heavy metal also present in this water that may cause serious environmental diseases and pollution of surrounding water bodies.
Processes of Tin-Smelting Wastewater Treatment
Tin smelting wastewater needs to be treated before discharging it into rivers and lakes. There are several physical, chemical, and biological processes that are used to treat this wastewater.
Physical processes: In physical processes, such as sedimentation and Filtration, suspended solids are removed from the wastewater. This will help reduce the COD of the wastewater. It can also reduce the amount of metal pollutants that are present in the water.
Chemical processes:In chemical processes, such as coagulation and flocculation, metal ions are removed from the wastewater. Coagulants like aluminum sulfate or iron sulfate are added to the wastewater to remove the heavy metals from it.
Biological processes:In biological processes, such as aeration and bioremediation, bacteria is used to breakdown the organic matters in the wastewater. Microorganisms will also help to reduce the COD of the wastewater.
Conclusion
Tin smelting wastewater needs to be treated properly before discharging it into rivers and lakes. There are several physical, chemical, and biological processes that can be used to treat this wastewater. The most effective way of treating tin smelting wastewater is by using a combination of these processes. Proper treatment of tin smelting wastewater will help prevent environmental pollution and contamination in the surrounding water bodies.
