In the course of treating wastewater, some residues are bound to be left behind. This residue arises mainly when the liquid component of the water is extracted fully. Knowing how to handle and tackle this sludge is no doubt critical to the wellbeing of the environments in which the wastewater is found.

That is why we have seen it appropriate to dedicate the entire length and stature of this article towards that subject matter. In our discussions about this issue here below, we shall examine the matter from all angles for you to take note of.


This is a kind of solid, slurry, or semi-solid residue that arises mainly as a byproduct of the treatment of wastewater. It is for a large part deposited as sediment right at the bottom of the septic tanks or the septage. The residue comprises both the dissolved organic and inorganic matter alongside a host of trace elements.

When dried and treated, this residue may be disposed of in a landfill, utilized as fertilizer, marketed as a bio-solid compost, or used for landscaping. If it is left exposed to the external elements, however, it may pose threats to the safety of wells and the environment as a whole.


Sludge dewatering refers to the process of extracting water from the wastes to give rise to a dry and compacted sludge. This water is often purified further and used for drinking or irrigation. Alternatively, it may also be used in ponds and for the purposes of municipal cleanliness.

The typical process of dewatering entails passing the wastewater in a large centrifuge that works much the same way as a washing machine. Its spinning action generates a force that separates the water from the solid components that are dissolved in it. This in turn creates a bio-solid sludge.

After this separation has been attained, the water is then disposed of into a larger container which then channels it further away for eventual drainage. The sludge that is left behind is dried out and then packed for further disposal in a landfill or processing into fertilizer.


There are numerous ways in which the sludge may be de-watered. Some of these stand out by virtue of being effective and easier to tackle. We now get to examine the methods that may be used for dewatering the wastewater:

a.) Belt filter press

It is by far the most popular method in use at the moment. Mostly, it is used to tackle wastewater that has a higher moisture content in it. When all is said and done, the process gives rise to around 18-25% of the solid output by weight.

Unlike other methods, it operates continually and is hence pretty effective on the high-volume waste streams in which large-scale productions of the low-quality filter cake are admissible. For these reasons, the process is largely preferred in municipal wastewater treatment plants.

Besides the extraction of wastewater, this process may also be used for:

  • Papermill sludge
  • River silt
  • Municipal wastewater treatment sludge

b.) Centrifuge

A centrifuge is a gadget that makes use of high rotational speeds to set apart components of various densities. Those components that are weighty and dense often settle at the bottom of the containers whereas those that are lighter remain at the top. That allows for easier physical separation thereafter.

It is generally faster than other ways of making such separations. Nonetheless, it may only apply in instances where the quality of the sludge is not much of a concern. The two areas that extensively employ it are the heavy oil sludge de-watering and the municipal wastewater treatment sludge dewatering.

c.) Plate and frame filter press

This appliance uses a set of recessed chamber plates to set apart the liquids from the solids. In this instance, two plates fuse together to give rise to a chamber that ultimately pressurizes the sludge to squeeze out via a filter cloth that lines the interior chambers.

Its end product, called the filter cake, is deposited on the surface of the filter plates and then passed on to a horizontal conveyor. Of all the methods that be, this generates the highest content of solid material that also allows for smoother transportation and disposal thereof. It is mostly used if dry solid matter is the main target.

d.) Biological sludge

From its name, you can straightaway infer that the exercise depends extensively on the biological processes to generate solid matter. It gives rise to stackable and cake-like solids that are easier to transport to the designated locations of final disposal.

One beautiful thing is that you need no special licensure to operate such kind of a machine. Nonetheless, you need specialized pieces of equipment and have also to exercise a great deal of patience to accrue the necessary outcome. Only those with the necessary expertise may handle and make use of it hence.

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Several pieces of equipment are used to tackle this entire exercise. We now devote this last segment to look into these items:

a.) Aeration wastewater equipment

This one makes use of the biological processes to tackle the menace of wastewater. To do this, it taps into dissolved oxygen to suppress the formation of anaerobic zones while also encouraging the growth of the microorganisms. To make these conditions possible, the piece of equipment relies on rotor aerators.

b.) Automation equipment

For large-scale wastewater treatment, automation equipment comes in handy. It does not constant handling and prolonged attention. These two make it able to handle huge volumes of wastes with minimal effort and attention on your part. Some of them also have sensors that detect the varying external conditions and respond to them appropriately.

c.) Sludge pits

Sludge pits are used for the storage of the wastewater prior to the eventual disposal of them or treatment. It is in the pits as a matter of fact that the sludge is formed. These pits are made of impervious materials that are unlikely to seep out the wastewater to the surrounding environments.

d.) Sewage pumping stations

These are stations that have pumps that introduce or up the levels of pressure in the pipes that transmit the same to the municipal drains. They are largely employed when there is a long distance to cover or when the systems have to handle a huge volume of wastes per unit of time.

e.) Pumping equipment

Just like the pumping stations, these too play the role of increasing the pressure of the wastewater in the pipes where the same might be transported to the municipal drainage. They differ from the above though with regards to their size and handling capacities. That is because they are smaller and mainly used for small-scale operations.

f.) De-watering bags

De-watering bags are special bags that are used to contain the sludge temporarily while at the same time extracting water from the same. In most cases, they are used within the home environment only. Those who are far away from the municipal wastewater treatment complexes may find it quite handy.

g.) Filter presses

A filter press dewaters the sludge by use of a pressing mechanism and through a series of porous plates. The force of the press squeezes the water from the sludge and into a collecting chamber. It contains a series of 20−80 rectangular plates that are recessed to allow for the filling of the sludge. Thereafter, a finer cloth that has a small pore size that measures no more than 0.1 mm filters out the residues to give rise to clean water outcomes.


Also called a de-watering screw press, this is a special kind of press that works to separate the solids from the liquids. It may be used in the stead of the filter paper, centrifuge, and belt press. The item is simple and slow-moving, not to mention of course being manually operable.

For a large part, it is largely used for domestic applications as it is smaller and manual in nature. The prolonged use of the item usually tends to tire the users though. After separating the liquids from the solids, it channels solid deposits to a filter or a screen to have the same collected for eventual disposal.


Wastewater sludge is potentially dangerous when left exposed to external elements. You can never hence afford to handle it recklessly as it may imperil the lives of those who are around you. As a sure way of going about this, we ask that you arm yourself appropriately.

This could take the forms of acquiring and equipping yourself with the needed for the job, making contacts with the nearby municipal offices in charge of waste disposal, and the enrolment in the provisions of these services, to name but a few! Go now for these services!

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