Industrial Pulp and Paper Mill
Supplemental Aeration
One of the world's leading pulp and paper manufacturers required extra air in one of their paper mill WWTPs in Asia. Equipped with surface aerators and jet mixers, the plant treats approximately 20,000 m3/day in two activated sludge reactors.
The plant treats more than 2.5 million m³ of municipal wastewater annually with an average daily flow rate of 7,000m³/day in an SBR process. The existing aeration systems in the SBR lagoons comprised of 6 floating aspirator units, combining mechanical mixers with coarse bubble diffusers, designed to deliver oxygen of 420 kg/hr under standard conditions. Each unit included a mixer with the capacity of 7.5 kW and a regenerative blower of 22 kW, but the system did not achieve the expected results according to the design specifications.
Challenge
The client needed to increase the plant’s oxygen supply to comply with regulations and maintain consistent production. They were seeking an aeration system that could withstand the harsh industrial wastewater and could increase the dissolved oxygen in the reactor.
Solution
To replace the existing jet aerators with Mapal’s floating aeration units. Mapal’s aeration system was connected to the existing blower. Due to the system’s efficiency the oxygen flow rate increased which resulted in a higher dissolved oxygen concentration in the reactor.
Results
Installation alongside the surface aerators was safe, simple, and carried out without stopping the treatment process. Once Mapal’s floating aeration system began to operate there was an immediate improvement in the reactor’s oxygen level. One week later the client reported oxygen increase to the required level and that the color of the wastewater transformed from grey to brown, indicating improvement of the treatment process. Following the project’s success, the client purchased an additional Mapal aeration system with nine floating units, in order to upgrade the entire wastewater treatment process of the production plant.
