Wastewater treatment
Nitrogen can be used in a targeted manner to influence microbial growth. The controlled addition of nitrogen from the air has been shown to increase nutrient absorption and improve the efficiency of the cleaning process. This natural component of the air plays a crucial role in optimizing wastewater treatment.
Nitrogen as a performance accelerator for wastewater treatment plants
Modern wastewater treatment plants rely on microorganisms to perform important tasks in various treatment stages. Bacteria, fungi and protozoa incorporate the components of the wastewater into their metabolism, resulting in a biological process that cleans the wastewater. Evonik’s membrane modules can accelerate these processes by optimizing the living conditions of the microorganisms in a targeted manner. Bacteria are doped with oxygen, which is obtained locally using SEPURAN® N2 membrane technology and supplied selectively. This promotes the growth of the bacteria, allowing them to work more efficiently.
Based on the same SEPURAN® membrane technology, another gas from the air - nitrogen - can be added in the upstream solids separation process to slow the growth of the microorganisms. This lets more nutrients into the biological process of cleaning the wastewater. With Evonik membranes, operators of wastewater treatment plants are able to precisely determine the biochemical boundary conditions for each wastewater treatment stage. This allows them to operate their processes much more efficiently and expand plant capacities without major construction work.
Another gas separation membrane from Evonik—SEPURAN® Green—also makes it possible to purify the biogas, which accumulates during the wastewater treatment processes, into high-purity biomethane that can be recovered and reused in a circular economy model. The CO2-neutral gas can be fed directly into the municipal natural gas grid or used as a green fuel (bio-CNG) to power municipal vehicles.
