What Are The Different Types Of Pumps Used For The Wastewater Treatment Process

The different types of pumps used for waste water treatment

For any business in the wastewater treatment industry robust pumps which can handle everything from effluent to sewage, are crucial for successful, streamlined operations. Which type of wastewater treatment pump you choose will depend on the type of wastewater being pushed through, flow rate, duty cycles, pressure, abrasiveness, and cost-effectiveness.

Pumps made for clean water will likely sustain damage if used for wastewater, causing pump failure or a steep drop in performance and efficiency.

Having the right pumps in place can make your wastewater treatment process more efficient and ultimately reduce ongoing operational costs (Opex).

Pump Challenges

Wastewater treatment companies may face several issues when pumping water through their systems because wastewater will often contain debris or particulate which can impact efficiency. It’s essential the right pump is chosen for the right job to minimise the following challenges:

  • Blocked pumps – This is a common issue because wastewater naturally contains debris which can impact the flow rate and increase resistance leading to greater wear and tear and pump damage or malfunction.
  • Equipment abrasion - The nature of wastewater with its inherent debris and particulate means the types of pumps used in wastewater treatment are likely to experience a high degree of wear and tear. Even fine particulates can have an abrasive action on pump parts which require regular maintenance and replacement.
  • Chemical and pH damage – Some chemicals used in wastewater treatment are highly corrosive, leading to a higher rate of pump degradation and corrosion. The pH of wastewater can naturally range from acidic to highly alkaline, requiring careful material selection for the ‘wet-parts’.
  • Bubble formation and high-pressure shock waves (Cavitation) – Bubbles can form because of the vacuum created by a pump’s impeller. When these bubbles burst, they cause shock waves inside the pump which can impact a pump’s efficiency and increase damage.

The Different Pump Options

There are four common pump types suitable for the wastewater industry. All come with their own advantages and disadvantages depending on usage, capacity and flow

1. Centrifugal Pumps

Centrifugal pumps operate by using centrifugal force – an impeller rotates inside the pump, pushing fluid outwards from the centre and into the pump’s discharge.

Centrifugals designed for the wastewater treatment process are fitted with open impellers because they don’t tend to clog so easily. Split-casing makes maintenance and inspection easier. Designed to pump abrasive fluids continuously, any parts that are wearing out can simply be replaced rather than having to replace the entire pump unit

2. Submersible Pumps

Submersible pumps are another type of pump commonly used in the water industry. These watertight pumps are designed to work in an upright position and are fitted with seal failure devices, which protect against motor failure.

Parts such as impellers and wear plates are made from high chrome or iron to reduce wear and tear and increase lifespan, while some will come with an agitator to keep solids in suspension and reduce the risk of clogging

3. Progressive Cavity Pumps

Progressive cavity pumps have a unique screw design, invented by René Moineau. The design has multiple rotating chambers that progressively push fluid along the length of the pump. The advantage of this is it ensures precise fluid displacement and consistent flow rates.

They’re ideal for usage in the water industry where a seamless, efficient and continuous process is required. They’re capable of handling viscous sludges and, with the right stator/rotor geometry, fluids with suspended solids. Because they’re particularly suited to handling wastewater sludges, they can aid in increased efficiency and cost effectiveness of wastewater treatment. In addition, they also require less energy to run than some other types of pump

4. Industrial Peristaltic Pumps

Large, industrial peristaltic pumps (hose pumps) have been developed to transfer highly viscous sludge and near-dry sludge. With these pumps, a section of flexible pipe fits around a rotating arrangement of rollers which squeeze the media to generate flow.

The hoses are made from abrasion-resistant rubber, which is both long-lasting and inexpensive to replace. Being a type of ‘positive displacement’ pump, it is able to produce good flow and pressure with lower rotation speed than a centrifugal pump.

Different pumps will suit different applications – we can tailor solutions to your industry and usage-specific requirements. Bring your water industry challenges to us and we will help you find the right high-quality pumps to do exactly what you need. Call 0808 196 4938 or complete our contact form.