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Designing a wastewater treatment plant can be a daunting task. Among all the factors that the designer must consider, some of them are in direct conflict. It can be a delicate balancing act to find the correct combination of optimizing one factor while perhaps making another outcome less desirable. Each plant will have its unique combination of the most important results.
Here are the factors affecting WWTP designs:
- Throughput volume.
- Required quality of effluent.
- Future changes in demands or quality requirements.
- What’s unique about the site – unusual elevations, footprint limitations?
- Weather factors – heavy snow or rain, extreme temperatures or wind.
Using traditional manual calculations, an engineering team including several disciplines will take many weeks to produce a design. By the time they face the need for a treatment plant, most communities are in emergency status. They need the plant yesterday! The engineers are under great stress to do the design quickly and may not be able to offer the options for treatment designs that plant owners would ideally like to consider.
At Transcend Water, the expert engineers saw how this unfolded in most projects and created the Transcend Design Generator. This SaaS application can work through the labyrinth of conflicting considerations and produce a preliminary design in about 8 hours. The tool can quickly consider design changes or more process options.
Selection of the Optimum Treatment Process
Most WWTPs use one of these processes:
- Conventional activated sludge (AS, CAS)
- Membrane bioreactor (MBR)
- Moving bed biofilm reactor ( MBBR)
- Integrated fixed film activated sludge (MBBR IFAS, IFAS)
- Sequencing batch reactor (SBR)
Wastewater treatment plant in Switzerland – credit pixabay.com
The MBR process produces the cleanest effluent. It’s more expensive to operate, using the most energy of all the processes. For some locations, the clean effluent consideration may override the cost factor. One consideration that can offset the higher OPEX is that an MBR plant may be less expensive to build. If the discharge area is less sensitive, perhaps one of the lower operating cost options will suit better.
Many clients looking at these tradeoffs will want to consider more than one option. This is a big problem for the manual design teams. With the weeks-long WWTP design process, considering several options may be too costly in terms of time. They’re almost forced into considering only one or, at the most, two options.
Fortunately, Transcend Solves This Dilemma
Transcend Water decided ten years ago to develop a tool to give clients options to choose from while taking the time stress off the plant designers. Their team of hydraulic, mechanical, civil, and chemical engineers became computer programmers and created the Transcend Design Generator (TDG), an SaaS application that gives design engineers the capability of producing a preliminary WWTP design in as little as 8 hours. This tool is revolutionary in the industry and is used worldwide by some of the largest water companies.
If you set out to make a complex financial decision by incorporating all the interest rates, contract terms, etc. into a manual calculation, it may take days to come up with one answer. Then, if you want to change one of the factors, you have to redo much of that work. Build an Excel spreadsheet, and you can change something and have a new answer in a few seconds. That’s the equivalent of what the TDG does for WWTP design.
This tool is so versatile that students, salespeople, and others with less engineering experience can find good value in it, even if they wouldn’t produce a complete quality design as an experienced water engineer would. Engineers using it as a tool to create full preliminary designs save a tremendous amount of time in their work and turn out a superior design.
Efficient Design and Operation Demands Automation
You’ve seen how much of the design process is automated by the use of the TDG.
The feed water to many WWTPs is household waste. Think about your family household routine, and you can see that inflow volumes to these plants will vary significantly throughout the day and week. To accommodate that variation, the operators must adjust the process from time to time. Modern sensors and real-time analysis provide them the necessary information to make those adjustments accurately,
To summarize, in pre-TDG times, WWTP design was time-consuming. When time is not in abundant supply, as is the case with most wastewater treatment projects, the time pressure on the designers was tremendous. They often had to short-cut the process selection decision. This short-cut could result in a less-than-optimum design for some plants, but the delay in considering more options could not be tolerated. Engineers were under tremendous stress, with long work-days, few if any breaks, and no family life. The TDG gives them back their lives.
With Transcend Water’s design generator, the right choice can be made, while the plant construction can still proceed without delay. This tool has moved Transcend to a position of leadership in the worldwide wastewater treatment design industry. At their website, you can learn more about how this unique tool works and contact their experts to discuss your unique needs.
