Sewage sludge is defined as the byproduct of treated wastewater. It is made of both inorganic and organic materials and has a large volume of plant nutrients, organic chemicals and even pathogens in them.

The disposal of sewage sludge without suitable treatment can create environmental and health hazards. This is why the use of ideal sludge treatment equipment to carry out the treatment process steps is vital.

Below we have enumerated the vital steps in which the wastewater sludge treatment process is carried out. Keep reading till the end to find out about them.

  1. Thickening Process

The first step that goes into a sewage sludge treatment plan is known as the thickening process. Here the sewage sludge is thickened typically in a gravity thickener.

The main intention of the thickening step is to reduce the sludge volume. Sludge in its raw and untreated form contains numerous suspended particles and solids along with water concentrates. The overall content makes it incredibly difficult to handle and treat sludge.

Thickening process helps in getting better control over sludge handling. Aside from gravitational thickening, dissolved air flotation can also be used alternatively for the sludge thickening process, where air bubbles are introduced to enable the solid mass to float to the surface.

  1. Digestion Process

Sludge digestion is a biological process that comes after all the solids from the sludge are amassed. In this step, all of the organic solids that are present are decomposed and transformed into stable substances.

This process further helps in reducing the total sludge volume while at the same time destroying any pathogens for enabling easy dewatering in the later stage. The sludge digestion process is carried out in two phases.

  1. Dewatering

After the digestion process is completed, all the useful gases and other byproducts are retrieved. Whereas, the sludge that remains after is sent for the dewatering process before they are ultimately disposed of.

In spite of its solidified state, the dewatered sludge contains as much as 70% of water and this is why it becomes essential to dry and then dewater the sludge beforehand. Sludge-drying beds are the most common way to carry out this process, however, they are extremely time-consuming.

This is why there are many waste management plans commissioning the use of solid-liquid separation equipment to accelerate this step and ultimately complete the process of dewatering properly. There are also alternative solutions available for quickening this step.

  1. Disposal

Once the sludge is dewatered effectively, the next step involves disposal which is basically done burying the sludge underground in a sanitary landfill or can also be used as fertilizers, based on its chemical compositions.

In case if the sludge is too toxic for underground burying or used as a fertilizer then they are incinerated and converted into ash.

The sludge treatment process more or less includes these steps, however, companies that are involved in sludge treatment have a requirement for quality sludge treatment equipment to carry out these steps properly.