Innovative Wastewater Treatment: How Walailak University Achieves Environmental Sustainability

09Oct 2024 by Kittipong Bunlear

Sustainability and Stewardship

In 2023, Walailak University continues to prioritize and operate its wastewater treatment processes through the university’s wastewater treatment plant, ensuring environmental sustainability and the well-being of the community by protecting the quality and quantity of water sources. The current system has the capacity to treat 950 cubic meters of wastewater per day from various buildings on campus. The process in place to treat wastewater is collected, processed, and reused within the university.

Figures : Development Project of Wastewater Management System at WU

Recognizing the environmental and ecological impacts of wastewater, the university operates an Aerated Lagoon (AL) system that can handle 4,000 cubic meters of wastewater per day. This system uses floating aerators to increase oxygen levels in the water, facilitating faster decomposition of organic matter by microorganisms. This accelerates the breakdown of wastewater and reduces its Biochemical Oxygen Demand (BOD) by 80-95%. The system relies on aerobic microorganisms that thrive in oxygen-rich environments, which is ensured by aerators that mix and circulate the water within the lagoons, promoting efficient treatment.

The wastewater treatment system at the university is designed as a biological treatment process. Once treated, the wastewater undergoes quality assessments through scientific analysis and tests conducted using four tilapia fish ponds. After ensuring compliance with the discharge standards set by Thailand’s Pollution Control Department, the treated water is either reused or released into natural water bodies. The university also reuses treated water for activities such as road cleaning and watering plants in the university grounds.

The university has continually refined its wastewater treatment process, upgrading its mechanisms and technology in 2023 to enhance efficiency. The wastewater treatment process can be categorized into three main stages, as follows:

1. Preliminary and Primary Treatment:

1.1 Each building on campus is equipped with a physical wastewater treatment system that ensures compliance with standard regulations before the wastewater is discharged. This includes screens that filter out non-dissolvable solid waste and grease traps that separate fats and oils from the wastewater. These systems help maintain the initial quality of the water before it proceeds to the next treatment processes.

1.2 Wastewater from all buildings is collected for treatment through the Wastewater Management System Development Project of Walailak University.

1.3 The collection system uses trash trap to remove solid waste from the water before it enters the treatment facility, preventing blockages and damage to pumps.

1.4 After solid waste removal, 500 liters of microbial inoculants are added to the collected wastewater at wastewater pumping station before it is pumped into the Aerated Lagoon (AL) for further treatment.

2. Secondary Treatment:

2.1 Wastewater is pumped through pipelines into the Aerated Lagoon, where aerobic bacteria decompose organic substances.

2.2 The wastewater is then transferred to Facultative Pond 1, where it is retained for at least four days. Aerobic microorganisms reduce the BOD by 60%.

2.3 Subsequently, the wastewater is moved to Facultative Pond 2, where it is retained for at least seven days. This biological treatment stage removes impurities, particularly organic carbon, nitrogen, and phosphorus, reducing BOD by approximately 50%.

3. Tertiary Treatment:

3.1 After secondary treatment, some pathogens may still be present in the treated water. Therefore, before discharging the treated wastewater into natural water source or reusing it, the water is disinfected using ultraviolet (UV) light to eliminate harmful microorganisms. The university maintains and replaces the UV lamps annually.

3.2 The treated water is stored in a constructed wetland (WETLAND) for further assessment and reuse. This wetland also serves as an ecological study area for the university.

3.3 The quality of treated water is assessed through scientific analysis and fish pond tests before being reused or released. The treated water meets the effluent standards set by Thailand’s Pollution Control Department in 1992.