Emerging high-ammonia-nitrogen wastewater remediation by biological treatment and photocatalysis techniques

The bacterial and photocatalysis techniques have been widely applied into the remediation of ammonia nitrogen wastewater. Although traditional microbial methods had been verified useful; more efficient, energy-saving and con-trollable candidate treatment methods are still urgently needed to cover the increasingly diverse ammonia nitrogen pollution cases. The bacterial treatment technique for ammonia nitrogen mainly depends on the ammonia nitrogen oxidation-reduction (e.g. nitrification, denitrification) by nitrifying bacteria and denitrifying bacteria, but these reac-tions suffer from slow denitrifying kinetic process and uncontrolled disproportionation reaction. In comparison, the photocatalysis technique based on photoelectrons is more efficient and has some advantages, such as low temperature reaction and long life, while the photocatalysis technique can not perform multiple complex biochemical reactions. De-spite much scientific knowledge obtained about this issue recently, such research has yet not been widely adopted in the industry because of many concerns about subsequent catalyst stability and economic feasibility. This review sum-marized and discussed the very recent achievements and key problems on remediation of high-ammonia-nitrogen wastewater and oxidation driven by bacterial treatment and photocatalysis techniques, as well as the most promising future directions for these two techniques, especially the potential of jointly bacterial-photocatalysis techniques.

Automated summary

Bacterial and photocatalysis techniques are widely used for the remediation of ammonia nitrogen wastewater. While traditional microbial methods are proven useful, there is a need for more efficient and controllable treatment methods to address the diverse cases of ammonia nitrogen pollution. Bacterial treatment relies on ammonia nitrogen oxidation-reduction by nitrifying and denitrifying bacteria, but these reactions are slow and uncontrolled. Photocatalysis, on the other hand, has advantages such as low temperature reaction and long life, but cannot perform multiple complex biochemical reactions. This review highlights recent achievements, key problems, and future directions for remediation of high-ammonia-nitrogen wastewater using bacterial treatment and photocatalysis techniques, including the potential of combining bacterial-photocatalysis techniques.