The basic of wastewater treatment

Wastewater is used water that needs to be treated before it can be returned to the water cycle. Wastewater treatment describes the process we use to purify wastewater, to remove contaminants and make it cyclable again.

This treatment process is essential to return wastewater to a specified quality so that it can be used again or returned to nature.

Treatment phases

There are two basic phases of water treatment:

  1. Solids removal. This is the primary stage. Techniques used: Sedimentation, skimming, screening.
  2. This is the secondary stage. Techniques used: Reverse Osmosis, Ceramic Filtration, Ultrafiltration, Nanofiltration, UV filtration.

The steps involved in these phases and the technologies used depends on the kind of wastewater we are dealing with.

Technically, there is also tertiary treatment, a third stage to remove impurities. However, the right machine makes this part of the secondary treatment.

The right treatment can remove mud, solids, bacteria and viruses from water to render it fit for human consumption and industrial use.

Solids removal

Solids removal is the first treatment phase. Skimming, screening and sedimentation using clarifiers are the commonest techniques. Sedimentation is a physical process that removes particles using gravity or separation.

Sedimentation is sometimes combined with Chemically Enhanced Primary Treatment to increase effectiveness. This is a newer technique.

The Membrane Bio Reactor (MBR) is another way to remove solids. This removes solids from water using ceramic membranes to separate solids from liquid.

When removing suspended solids, we target solids larger than 80 microns. The removal of these solids renders wastewater usable in some industrial applications. Further treatment is necessary for human consumption and sterile environments.

Filtration

Filtration is the second treatment phase. Some might say that bacterial removal comes before filtration, but the two things fall under one process with the right technique. This saves time and reduces treatment costs.

Reverse osmosis (RO) is the most widely used technique, capable of removing 99.9% of bacteria from water. This purifies water to a quality that is fit for human consumption and without the need for UV treatment.

Other techniques include ultrafiltration (UF), ceramic filtration (CF) and ultraviolet filtration (UV). Ultrafiltration (UF) makes use of spiral membranes and blocks out viruses. This has led to increased investment in this technology during the COVID-19 pandemic.

Which wastewater treatment is best?

There is no ‘best’ wastewater treatment, only the right treatment for the kind of wastewater being treated and your intended use case.

For example, water that is being treated for human consumption will require a more comprehensive treatment process than water that is going to be used by sprinkler systems.

To use another example, the finishing water used in automotive production requires a  precise specification. This specification is unique to that single application and is not found elsewhere, such as in the food and beverage industry.

Investing in the latest treatment processes

The coronavirus pandemic has forced those responsible for the treatment of wastewater to accelerate their investment in new treatment technologies.

Our financial flexibility packages provide an affordable route to new investment with the option to purchase equipment on a Lease Purchase Agreement (LPA) or Hire. These finance packages cover all our treatment systems.

We are also happy to provide advice to help you build a comprehensive wastewater treatment facility so you can meet your purification requirements. We’re here to help, so feel free to reach out to us for a friendly chat.