Water is a valuable resource. Its value is evidenced by the fact that we use it daily, even in industry. However, there is a tacit understanding that fresh-water availability is not perpetually guaranteed. Therefore, careful use must be made of what we do have at the moment. That is why today, the topic of wastewater filtration appears prominently in discussions throughout the construction, mining and industrial industries.
Wastewater filtration refers to the process of extracting any solids, chemicals and oils present within a given volume of water. This removal is done to make the water safe and hygienic for re-use. The act of wastewater filtration gives two advantages: it is good for the environment and helps to ensure equipment longevity.
How does wastewater filtration work?
In most cases, the filtration process happens in two major steps:
During the primary treatment, wastewater flows through an initial screening area where large solid debris like rocks, wood and even dead animals are removed. This first step is crucial in preventing potential blockages further down the line.
Once the screening process is complete, the water gets pumped through a stage where the remaining organic and inorganic matter and other solids can be trapped and extracted. This process occurs within a sedimentation tank. Some plants use paper bed filters to catch any solids within the water flowing through in this instance. These filters are particularly advantageous because they require no human interaction during operation.
The sewage is pumped into a separate area where the second treatment occurs as soon as the initial filtration is complete. Here, the facility shakes up the sewage to aerate it, thus allowing any trapped gases to escape. Next, the water goes into a series of parallel tanks further subdivided into two sections. The first section pumps air through the sewage to keep any organic matter suspended while grit settles and is then removed and taken to a landfill.
After the grit is filtered away, the organic matter, known as sludge, is extracted by allowing the water to flow into the second section. In this portion, the sludge is left to settle before pumps are used to remove it. At this point in the process, the need for sludge management arises. This requirement then necessitates the use of a vacuum filtration system. The system works similarly to the paper bed type, although its employment mainly targets the sludge.
The vacuum system works by drawing air from water flowing over a conveyer belt. Filtration devices then capture any solid materials and turn them into a cake-like form. The vacuum then aids in pumping air through this ‘cake’, therefore drying it and rendering it ready for disposal.
Once you have extracted the sludge and used a sludge dewatering system to dry it out before disposing of, you are now left with filtered water. This remnant is now safe for re-use or left to flow as sewage. If it is to be allowed to flow back into the waterways, the plant usually treats it with chlorine to kill any remaining bacteria. In addition, they add other chemicals to neutralise chlorine to preserve marine life.
In-house wastewater filtration is an integral part of industry responsibility. Using the practice is also highly beneficial for both the environment and the business.