With industrialisation came urbanisation and challenges associated with the new way of life. Before the 1960s, most towns and cities disposed of their wastewater in nearby rivers, with little or no regard for treating it before disposal.
As the urban population grew, continued disposal of effluent in rivers caused severe pollution. To solve this environmental crisis, wastewater treatment plants were established. From this, a new challenge arose, how to safely dispose of sludge, a by-product of wastewater treatment.
How sludge is formed
Industrial and municipal processing results in sludge or slurry, a by-product of specific chemical reactions during wastewater management.
A mass of sludge is produced during the biological aerobic or anaerobic treatment of water, wastewater, or sanitisation. Sludge is characterised by a combination of solids and liquids and looks like a thick, muddy substance.
The sludge needs to be further managed to be safely and properly disposed of. This is when sludge dewatering comes into play.
Understanding sludge dewatering
Put succinctly, sludge dewatering is the process of reducing the volume of waste to facilitate its disposal. This is done by putting the sludge through a dewatering filter press which separates the excess liquid from the solid mass. The solid waste is then caked to ease the waste management process.
Methods of sludge dewatering
Factors determining which technique will be used in the dewatering process include sludge porosity, available budget, and space and capacity required.
- Belt filter – this is a gravity dewatering process, where belt filters move the sludge through a repeated cycle of draining and squeezing out the excess water. This is a cost-effective dewatering solution.
- Centrifuge – a cylindrical bowl containing the sludge is spun at high speed to separate the solids from the liquid. The process results in the formation of a solid cake with reduced moisture content. Although this method is space-saving, it’s more expensive to facilitate.
- Frame filter – Filters drain water from the bottom, and the sludge forms cakes within the filters.
Advantages of sludge dewatering
Here are some of the benefits of sludge dewatering.
Reduction of waste volume
With the reduction of the waste product’s volume, disposal costs will be significantly reduced. The solid caked waste can then be efficiently and cost-effectively disposed of.
Lowered transport and storage costs
Sludge is a heavy mass. Trying to move it along the system through piping may result in damage through pipe blockages. Once the sludge has been dewatered, it becomes lighter and cheaper to move. The dried cake is also simpler and more affordable to store while awaiting transfer to the processing plant.
Reduced risk of leakage
Not only is transporting sludge costly, but it poses environmental risks through the possibility of leakages or spillage while moving it from one location to another. As a solidified mass, the likelihood of leakage of toxins into the environment is lessened.
Recycling of wastewater
Sludge dewatering provides a green solution to waste management through recycling. When the water is separated from the solid waste, it is treated to remove pollutants and re-directed for use in other industries or communities. The recycled water can be used to power steam-powered industries.
The right solution for managing your waste
Getting your wastewater processed efficiently and effectively shouldn’t be an arduous task. Interfil has various industrial filtration systems and waste management options to suit your budget, space, and capacity.
With Interfil’s long-standing track record, you are guaranteed the right solution for your sludge dewatering project.