School wastewater primarily originates from the daily activities of students, teachers, and functional areas such as restrooms, canteens, kitchens, and dormitories. Although its composition is relatively similar to domestic wastewater, a notable characteristic of this waste stream is that the flow rate often fluctuates according to school hours, school days, and holidays throughout the year.
For large-scale schools with multiple functional areas or boarding activities, determining the capacity based solely on the number of students may not fully reflect actual operating conditions. The system needs to be calculated simultaneously in terms of flow rate, pollution load, equalization capacity, treatment technology, and output water quality requirements. Therefore, the design of a school wastewater treatment system needs to start from correctly surveying the emission sources and operational characteristics of each educational facility.
Depending on the type and scale of the school, wastewater can originate from various areas:
| Emission Source | Wastewater Characteristics |
| Restrooms | Organic matter, TSS, Ammonia, Nitrogen, Phosphorus, and microorganisms |
| Handwashing & general hygiene areas | Organic matter, detergents, and suspended solids |
| Canteens, kitchens | Grease, food scraps, COD, and BOD |
| Dormitories | Domestic wastewater generated at multiple times throughout the day |
| Laboratories | May contain chemicals or specific components requiring separate evaluation |
These waste streams cannot always be collected directly into the same system.
Wastewater from canteens and kitchens needs to have grease separated before entering the biological treatment works. If uncontrolled, grease can accumulate in pipes, treatment tanks, and affect the operation of the microbial system.
For laboratories, it is necessary to determine the actual wastewater characteristics. Waste streams containing chemicals or components capable of affecting the biological process need to be collected, pre-treated, or have a separate, appropriate management plan. Therefore, fully surveying the emission sources is an important step before determining capacity and selecting the treatment technology.
In terms of composition, school wastewater mainly carries the characteristics of domestic wastewater with parameters of concern such as BOD, COD, TSS, Ammonia, Total Nitrogen, Total Phosphorus, and microorganisms. However, a more notable issue lies in the fluctuation of flow and load over time.
For day schools, wastewater is usually concentrated at the beginning of the day, during recess, lunch breaks, and at the end of the session. The flow decreases significantly in the evenings, on weekends, and during holidays. Conversely, universities or educational areas with dormitories may generate wastewater for most of the day, with operational characteristics closer to a concentrated residential area.
This disparity directly affects the treatment system. If the flow increases rapidly over a period of time but the equalization capacity is insufficient, downstream works run the risk of sudden high loads. Meanwhile, during long holidays, a sharp decrease in wastewater volume and nutrient sources can cause the microbial system to lose activity if there is no suitable operational plan.
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School wastewater treatment
One of the important factors when designing the system is accurately determining the actual wastewater volume.
Besides the total number of students and teachers, additional considerations include:
For schools with large flow fluctuations, calculating based solely on average daily flow may not be enough. The capacity to receive wastewater during peak times and the equalization volume must also be considered to limit situations where the system has sufficient daily capacity but is still locally overloaded.
Depending on the wastewater characteristics, capacity, and output requirements, the technological process can be adjusted for each project. A school wastewater treatment system usually includes the following stages:
In the initial stage, wastewater is collected, and large-sized trash and debris are removed to limit pump and pipe blockages and protect downstream equipment. Specifically, wastewater from canteens or kitchens must have grease separated before entering the common system to limit grease accumulation and its impact on the biological treatment process.
After pre-treatment, the wastewater is sent to the equalization tank. This is one of the important items for schools because wastewater flow can change significantly depending on the time of day. The equalization tank helps balance the flow and pollution concentration, limiting sudden load surges before the wastewater is transferred to subsequent stages.
The biological treatment stage takes the main role in removing organic matter and nitrogen-containing compounds. Depending on project conditions, technologies such as Aerotank, MBBR, AAO, or a combination of multiple treatment processes can be applied. The appropriate technology needs to be selected based on flow, wastewater characteristics, area, and output water quality requirements, instead of applying a fixed process for all schools.
After the biological process, wastewater is separated from sludge and continues through the disinfection stage before discharge. Sludge generated during the treatment process also needs to be collected and managed appropriately to maintain the stable operation of the system.
There is no single system configuration suitable for every school. Two projects with the same number of students might still require different solutions due to differences in operating hours, boarding areas, canteens, construction space, or output water requirements.
In practice, investors can consider between packaged composite wastewater treatment equipment and on-site constructed treatment systems.
Packaged composite wastewater treatment equipment is suitable for projects that need to optimize space, shorten implementation time, or limit on-site construction volume.
The treatment stages are integrated into prefabricated equipment, which is then transported to the project for installation and connection. Depending on the capacity and treatment requirements, the system can be arranged in one or multiple modules.
The advantage of this option is the reduction of on-site construction time, ease of arrangement in areas with limited space, and convenience for renovation projects or those needing to put the system into operation in a short time.
However, the equipment capacity, number of modules, and internal technology must still be calculated based on actual flow and pollution load.
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Composite wastewater treatment tank designed and installed by Dai Nam
Reinforced concrete constructed wastewater treatment systems are often considered when the project has allocated a technical area, has specific design requirements, or needs to integrate multiple treatment stages according to the actual conditions of the site.
This option allows for customizing tank sizes, technology layout, and connection with the project's infrastructure system. This is also a suitable choice when the investor needs to reserve the ability to increase capacity or expand the system in the future.
In return, the construction option usually requires more on-site execution time and demands close coordination with structural, architectural, MEP aspects, as well as the overall project schedule.
Therefore, choosing between a packaged system and a constructed system should not rely solely on capacity or initial investment costs. It is necessary to simultaneously evaluate the space, schedule, pollution load, operational requirements, expandability, and total cost during use.
In practice, at FPT University Ho Chi Minh City, Dai Nam designed and constructed a domestic wastewater treatment system with a capacity of 150 m³/day and night for a campus of nearly 30,000 m², serving a scale of up to 10,000 students.
For educational facilities with high usage density, correctly determining the flow rate based on operational characteristics and arranging suitable equalization capacity plays an important role in the stability of the system during operation.
The project also shows that school wastewater treatment solutions need to be designed according to the actual conditions of each site instead of applying a fixed capacity or technological configuration based on the number of students.
Project reference: FPT University Ho Chi Minh City Wastewater Treatment System
For the system to operate stably after being put into use, several factors need to be considered right from the survey and design stages:
Especially for systems arranged underground in basements or near study areas, factors such as ventilation, odor collection, vibration resistance, noise reduction, and equipment accessibility for maintenance need to be calculated right from the design stage.
A stably operating school wastewater treatment system depends not only on the treatment technology but also begins with correctly identifying the emission sources, flow rates, pollution loads, and operational characteristics of the facility.
For schools with canteens, dormitories, laboratories, or highly fluctuating flow rates by hour and season, these factors need to be carefully surveyed before selecting the capacity and system configuration.
Depending on site conditions and project requirements, the system can be designed as a constructed form or use packaged composite wastewater treatment equipment. The appropriate option must simultaneously meet the requirements for output water quality, operational capacity, construction schedule, and long-term costs.
With experience in implementing practical wastewater treatment projects, Dai Nam conducts surveys, consulting, design, construction, renovation, and operation of wastewater treatment systems for schools and educational facilities of various scales. Solutions are built based on the actual conditions of each project, aiming for stable operation and meeting post-treatment water quality requirements.
