Wastewater filtration removes impurities from sewage before it is recycled or released into natural water bodies such as lakes, oceans, and rivers. Generally, sewage is water that contains a considerable amount of pollutants such that it is unfit for drinking, fishing, and swimming.
Although natural conditions can affect water quality, most of the impurities in sewage come from human activity.
Importance of Wastewater Filtration
The most significant advantage of sewage treatment is that it conserves the environment. Secondly, it saves you money and reduces the health risks associated with consuming polluted water. That said, you need to invest in a system that ensures that the water you get is suitable for sewerage or reuse, and the solids are suitable for landfills.
The Filtration Process
Wastewater filtration involves three main steps – primary treatment, secondary treatment, and tertiary treatment. Each stage removes specific contaminants, with water being more transparent as it leaves every phase. In rare cases, quaternary treatment is used. This is mostly in large-scale industrial operations.
During this phase, wastewater is stored in huge tanks so that the heavy solids sink to the bottom and the lighter ones float. After the mixture settles, the solids are confined, and the liquid is discharged or moved to the secondary treatment phase, which is more thorough. It is worth noting that the tanks have scrapers that move the collected sludge for further treatment before disposal.
As the name suggests, secondary treatment is more rigorous than the primary stage. Its objective is to degrade the organic content in the wastewater using aerobic biological methods. When the water leaves this phase, it is safe for sewerage, as it has a reduced amount of biodegradable pollutants.
The three methods used in secondary wastewater treatment include:
- Bio-filtration: this uses contact, sand, and trickling filters to remove additional sediments from the wastewater.
- Aeration: this increases oxygen concentration in water. Despite lasting for up to 30 hours, aeration is incredibly effective at removing contaminants.
- Oxidation ponds: this uses natural bodies like lagoons to allow the wastewater to pass through, after which it is retained for up to three weeks. It is mainly used in warmer regions.
Tertiary treatment aims to make wastewater safe for human consumption and industrial use. It involves removing pathogens and other pollutants such that the water is suitable for drinking, swimming, and fishing.
The two techniques used for managing wastewater are paper bed filters and vacuum filtration systems.
Paper Bed Filters
Paper bed filters are popular because you don’t need to handle them when using them. Their operation relies heavily on gravity. Notably, you will require disposable filler material rolls to make a barrier and eliminate solids from the wastewater as it flows.
Vacuum Filtration Systems
Another technique for wastewater management is vacuum filtration systems. Although they operate like paper bed filters, there is an increased emphasis on treating the solid waste after the water is discharged. As the wastewater flows through the system, a vacuum below the conveyor belt suctions air from it. The disposable filter captures the sludge and forms a cake. The vacuum further draws air from the cake until it becomes dry. After drying, the cake is discharged into a bin for disposal.
Significance of Sludge Dewatering
Filtration produces water that you can either reuse or dispose of into a sewerage pond. The main challenge involves dealing with solid waste, called sludge. You need to devise a safe way of disposing of it. Besides being expensive, disposing of wet sludge is time-consuming. This is why you need to dewater the solid waste to make the disposal process easier and cheaper.
Wastewater filtration has numerous advantages. It conserves the environment and saves you the money you would have otherwise used to purchase more water. As a business owner, you can improve your profits by investing in the right water filtration systems.