The Crucial Role of Waste Water Treatment Plants
Today, several industries across verticals are committed to sustainable practices that don’t have a negative impact on the environment. Companies that produce or use fluids in their industrial processes are looking for innovative ways to dispose of the byproducts without damaging the environment and disturbing the ecological balance.
For instance, food and beverage processors, textile industries, chemical manufacturers, metal finishers and more generate fluids that have to be treated in accordance with local government regulations, before it could be discharged into the sewers or drains.
Today, everyone involved in the process – customers, shareholders, government bodies and manufacturers and industrialists are all concerned about adopting sustainable practices. There’s an increased awareness on minimizing resources and impacts on the environment.
Also, with water scarcity on the rise, more and more industries are looking for ways to recycle and reuse water. This is where, waste water treatment plants come into the picture.
And, industrial pumps are at the core of all wastewater treatment systems. Positive displacement pumps are used to transfer waste liquids (along with solid sludge) from one tank to another, throughout the process.
You need high-quality industrial pumps that can handle a range of wide fluids along with submerged solid particles.
The Role of Positive Displacement Pumps in Wastewater Treatment Processes:
- To transfer fluids from the sump to the reactor
- To draw slurry from the clarifier tank and feed it into the filter press
- For dosing chemicals into neutralizer tanks and the reactor
Here’s a Quick Working of Wastewater Treatment Plants
The process begins in the sump tank. Waste fluids (remnants of industrial processes) accumulate here. A positive displacement pump is then used to transfer the fluid to a second tank, where the water flow is equalized and then pushed into the reactor tank.
In the reactor tank, concentrated chemicals are added to the fluid to neutralize the pH levels. Here, a diaphragm pump or a metering pump is used to monitor dosage of chemicals. Finally, the neutralized liquid then flows into the flocculator, where special chemicals are added to particulates to make them coagulate at the bottom of the clarifier tank.
While choosing positive displacement pumps for wastewater treatment systems, you have to consider both the composition and the temperature of the fluid, which passes through the system.
Generally, there are four major pump options that industries use for sludge displacement. Each type has its own benefits and disadvantages.
Let’s take a closer look at each of these four major categories of positive displacement pumps, from the perspective of sludge transfer.
- Centrifugal Pumps
They are good choices for transferring sludges with low viscosity and very little immersed solids.
Centrifugal pumps generate significantly lesser pulsation, compared to the other positive displacement pumps on this list.
Unfortunately, centrifugal pumps come with a higher shear rate. As you would be aware, shear on sludge is hampers the treatment process. During sludge treatment, wastewater treatment plants aim for high sludge concentration.
If shearing happens, more sludge surface area is generated, which in turn disperses the solid substances, making it difficult to dewater.
- AOD (Air-operated Diaphragm) Pumps
AOD pumps are one of the most popular options for transferring sludge. The reason for this is that the operation of AOD pumps is quite simple and straightforward.
The AOD pump has a single diaphragm which is operated using compressed air. Controlling the pump’s speed is really simple, and the fluid displacement outcome is also easily predictable. It’s ideal for producing a uniform and consistent sludge blanket, which in turn, produces consistent solid sludge.
However, just like centrifugal pumps, AOD pumps too have high pulsation rates. As mentioned above, it uses compressed air for operation. If you don’t have an existing air compressor at the wastewater treatment plant, then operating this pump could become expensive, as you have to invest in an air compressor. On the other hand, if you have access to compressed air, then using this pump is relatively easy and inexpensive.
- Progressive Cavity Pump
This type of pumps handles sludge efficiently. They generate low pulsation rates and create zero to minimal shear on the sludge.
While progressive cavity pumps come with high efficiency, repair and maintenance become highly difficult. However, of late, many pump manufacturers including Sintech are coming up with new progressive cavity pump designs that are easy maintenance.
However, progressive cavity pumps have a bigger operational footprint. If you’re replacing an existing pump with progressive cavity pumps, then you’ll have to retrofit existing pipes to suit the new pump.
- Rotary Lobe Pumps
These pumps can handle fluids of high viscosity with ease. Just like progressive cavity pumps, rotary lobe pumps also have low pulsation and low shear. They come with a tiny operational footprint and accessing the interior parts is easy, via the front cover plate.
While rotary lobe pumps may feel expensive initially, they are worth it. This is because the amount you spend on maintenance, repair and replacement parts for rotary lobe pumps is far lesser compared to progressive cavity pumps.
The Last Word by Sintech Pumps
Indeed there are plenty of options available to you for pumping wastewater sludge. Ultimately, it depends on several factors like – the position of the sludge in the treatment process, the budget available, type of sludge, air availability at the wastewater treatment plant and more.
If you need further help with selecting the best positive displacement pump for sludge treatment, don’t hesitate to
ask us about it. Our pump experts, here at Sintech, India’s most reputed
sludge pump manufacturers, will help you find the right solution that meets your specific requirements.
