Which Chemicals Provide Oxygen for Aerobic Treatment for 12h?

Since we are planning to expand our wastewater treatment plant, we need to shut down the blowers and the aeration tank for 12 hours. This will affect the process and it will lead to a big loss to the company.  I am looking for alternative chemicals as a possible solution to prevent such a loss.  Are there any chemicals which can feed the aerobic treatment unit with required oxygen for the 12 hours?