Treatment of Rolling Mill Wastewater
With the development of society, the use of rolling mills has become increasingly widespread. Rolling mill wastewater is a type of industrial wastewater generated during the rolling process. This type of wastewater has some characteristics in common with other industrial wastewater, including usually high temperature and strong electrical conductivity. If untreated, it can cause serious environmental pollution and greatly reduce the operation efficiency of rolling mills. That is why it is necessary to seek proper ways to treat rolling mill wastewater.
In terms of the physical treatment of rolling mill wastewater, there are two primary methods: sedimentation and flocculation. The sedimentation process involves the use of gravity to separate suspended particles from the wastewater. The process takes time and results in the collection of heavy particles of material at the bottom of the container used for this process. Flocculation is a process that uses the addition of small amounts of various combinations of chemicals such as alum and ferric chloride to water. This process allows the suspended particles to clump together, making them easier to remove from the wastewater through sedimentation or filtration.
In addition to physical treatment, rolling mill wastewater can also be treated chemically. Chemical treatment involves adding chemicals such as sodium hydroxide, sodium carbonate and sodium tripolyphosphate to the wastewater to neutralize acidity and improve solubility. It is important to consider the potential environmental impact of chemical treatments and the potential risks to the operators conducting the process.
After the initial physical and chemical treatments of rolling mill wastewater, the wastewater may still contain high levels of pollutants. In order to reduce the environmental impact, additional advanced treatment technologies such as membrane filtration, activated carbon filtration, reverse osmosis and oxidation can be used. These treatment technologies can be used together depending on the types of pollutants contained in the wastewater.
Membrane filtration is a process in which the wastewater is passed through a special membrane material, resulting in the removal of particles and making the wastewater cleaner. Activated carbon filtration involves the addition of activated carbon to the wastewater, which absorbs pollutants from the wastewater before the filtration process begins. Reverse osmosis is a process in which the wastewater is pressurized to force it through a semi-permeable membrane, resulting in the removal of pollutants. Oxidation is a process in which oxygen is added to wastewater to break down organic pollutants.
Finally, the wastewater from rolling mills can also be treated by biological processes such as activated sludge, biological aerated filters, or constructed wetlands. The biological processes use microorganisms to break down organic pollutants and convert them into harmless substances. This type of treatment is an effective way to reduce levels of pollutants and help reduce environmental pollution.
In conclusion, the treatment of rolling mill wastewater is essential for reducing environmental pollution and increasing the efficiency of rolling mills. Physical methods such as sedimentation and flocculation, chemical treatments and advanced treatment technologies can all be used to effectively reduce the environmental impact of wastewater. Additionally, biological processes such as activated sludge and constructed wetlands can also be used to reduce pollutant levels. By using a combination of these strategies, rolling mill wastewater can be treated in an efficient and environmentally friendly manner.
