5 Keys to success in the execution of WWTP structures
Have you heard a lot about WWTP and don’t know what it is, or do you have to start the construction of a WWTP and it’s the first time?
Let’s see what a WWTP is, and what aspects must be taken into account for the execution of its structures.
A WWTP (Wastewater Treatment Plant), also called Water Purification Plant, is the place where wastewater from nearby towns is treated in order to be reused. Industrial wastewater treatment plants (IWWTP) are used for the treatment of industrial wastewater.
The objectives of a WWTP are the elimination of compounds containing ammonia and phosphorus, and the transformation of the retained waste into stable sludge, to ensure that they are properly utilized.
Water treatment stages
Traditionally, in a wastewater treatment plant, the following purification stages can be identified:
- Pretreatment: process in which large solids, sand and grease are removed.
- Primary treatment: removal of suspended solids (inert solids, particulate organic matter…).
- Secondary treatment: biological treatment that transforms the organic matter in wastewater into cellular matter, gases, energy and water.
- Secondary settling: separation of the treated water and the sludge generated in the biological process.
At this point, the water is ready to be reused, and the treatment of the waste sludge begins.
Sludge treatment stages
The sludge treatment line treats the by-products from the water line, so that they can be reused in agriculture, energy recovery, controlled landfill, etc, etc.
There are three phases in the sludge treatment process:
- Thickening: reduces the volume of sludge by removing water. This can be gravity-decantation or flotation. This phase takes place in special circular tanks.
- Stabilization: eliminates odors, organic matter and pathogenic organisms so as to reduce health risks. This phase is done by aerobic and anaerobic digestion, which takes place in large circular tanks.
- Dehydration and drying: decreases water content to facilitate sludge transport and handling.
Each phase of the purification, therefore, takes place in its own structures, and the most impressive are found in the sludge treatment phases.
These concrete structures are: Reactors, Decanters, Tanks, Digesters, Thickeners, and Separators, with a series of straight and curved concrete walls, usually between 3 and 15 meters high, depending on the volume for which they have been designed. This type of work poses a complexity in its execution, which can be solved and transformed into success if the right traveling companion is chosen.
What are the 5 keys to guarantee success in the execution of a WWTP?
1.- Know-how
When deciding which formwork company to work with, you can go through the so-called bidding process over several weeks. At this point, you will assess a series of factors: often the most important factor is the economic one, but it is important to understand that hiring the formwork company by prioritizing only the price factor does not guarantee the success of the project, nor that it will be the most economical result.
Finding a company with a wide experience and know-how in this type of work is highly valued by construction managers when they are faced with projects for water treatment structures, such as WWTPs.
2.- On-site technical assistance
The company in charge of the work needs its structures to be completed within the established deadlines, with no complications or delays. This peace of mind can be achieved with professional and experienced on-site service. A technical staff with whom to create this bond, teamwork, involvement and trust to take on and complete each of the different structures together.
In this type of project, several months usually go by from the time of the bidding process to the beginning of the construction phase, and there are often modifications to the designs, which can logically alter the formwork material forecasts that were initially made. This scenario could trigger some inconveniences, but with a committed and experienced technical service, they can be resolved perfectly on site.
3.- Planning
In civil works, it is very important to know when each concrete structure will be executed. In WWTPs, you have to plan these times and study each of these phases together, achieving great benefits in terms of the performance of all the formwork material, ensuring greater productivity and therefore lower costs.
The more planning, the more cost savings; simple, isn’t it?
4.- Versatile formwork
In WWTPs it is also essential to have a versatile, compatible wall formwork (both straight and curved) to resolve the adjustments to each of the different dimensions. In works of this magnitude, especially when they are located in geographical areas far from supply warehouses, they need to have the necessary material at their immediate disposal.
It is very beneficial for the construction site not to have to run over time, and therefore, by having formwork material of different sizes, it is possible to achieve this flexibility and versatility to resolve any adjustment and never suffer delays.
Versatility, logistics service, and material availability: there’s always something to check!
5.- Labor
Working with a qualified labor force is very important so as to avoid different kinds of inconveniences. In this type of project, workers’ experience can be decisive, especially for meeting deadlines. When working with unskilled or inexperienced labor, not only does productivity suffer, but there is also the risk of cost overruns when remedying possible faults in the execution of the structures.
In summary, in WWTPs and in large-scale projects in general, it is very important to choose and rely on suppliers that can guarantee a certain technical and logistical level both in the preliminary study phase of the project and in its execution. A company that can be a partner, rather than a supplier.
