Automatic and Flexible System for Aeration of Wastewater
For the aerobic degradation of organic substances, ie oxidizable substances in wastewater, oxygen is required, which can be introduced into wastewater by compressed air. In addition to supplying the necessary oxygen, these wastewater aeration systems have the function of mixing the wastewater with the sludge or preventing accumulations in the tank.
Reasons for wastewater aeration
Carrying out aeration measures in your wastewater treatment plant can increase the safety and degradation capacity of the system. The purpose of aeration is to achieve a rapid transition of oxygen from the gaseous state to the liquid state. This can be achieved by increasing the oxygen concentration in the air mixture or by a mechanical solution, produced by the optimal bubble size. Depending on the task required.
If, for example, the aeration of the wastewater is also combined with a mixture of the biomass, submersible aerators (rotor type) are implemented as an active system. In other cases, it is preferable to use passive systems, such as perforated pipes, membranes or air ejectors. In the case of uncomplicated wastewater in MBBR with a high organic load, perforated pipes are used, which are characterized by a medium bubble aeration. If laboratory analyzes show that the wastewater has low lime content, it is preferable to install membrane aerators in the activation facilities.
Flexible aeration of wastewater with air ejectors
If the wastewater treatment consists of removing not only lime but also large solid substances and sludge and also allowing separate mixing and aeration operation, air ejectors are preferably used. An example of this can be the degradation of nitric nitrogen, for which a mixture of the wastewater without air intake is needed.
Air ejectors can be removed during continuous operation, allowing system maintenance without completely shutting down the wastewater treatment.
Its advantages:
- Strong agitation and efficient aeration (separately controllable)
- Special nozzle design prevents effective bottom sludge build-up and keeps solids floating – regardless of the amount of oxygen entering
- There are no moving parts -> no need for special maintenance
- Ideal for use in MBBR or activation facilities
- Mobile solution allows maintenance during operation
Use of air ejectors in the paper industry
It is convenient, for example, to use air ejectors in calcareous wastewater, which is produced in the processing of waste paper. Lime deposits suffocate (clog) the membrane aerators at the bottom of the tank, which must compensate for the pressure loss with increasing power. The problem is solved by replacing the membranes with air ejectors. On the other hand, air jets add more oxygen to the water, whereby the reduction of COD in the same volume can be significantly increased.