How to increase microbial degradation in constructed wetlands: Influencing factors and improvement measures

• Microbial degradation is critical to pollutants removal in constructed wetlands.
• In this paper, key impact factors related to microbial processes are identified.
• This study reviewed current strategies used to improve microbial degradation.
• Special emphasis is given to the application of bioaugmentation in wetlands.

Microorganisms play a vital role in degradation of multiple pollutants in constructed wetlands (CWs). Thus, the search for methods to improve microbial degradation in CWs is crucial. This study provides a review of critical parameters including availability of organic carbon, redox condition, temperature, pH, presence of plants, media characteristics and their influences on microbial processes. Current strategies focusing on regulation of carbon source, redox condition, and choice of substrates to enhance microbial activity in CWs are also described. A special emphasis is given to the application of bioaugmentation to enhance microbial activities in wetland in future research.