Application of alkali-heated corncobs enhanced nitrogen removal and microbial diversity in constructed wetlands for treating low C/N ratio wastewater.

Lack of carbon source is the main limiting factor in the denitrification of low C/N ratio wastewater in the constructed wetlands (CWs). Agricultural waste has been considered as a supplementary carbon source but research is still limited. To solve this problem, ferric carbon (Fe-C) + zeolite, Fe-C + gravel, and gravel were used as substrates to build CWs in this experiment, aiming to investigate the effects of different carbon sources (rice straw, corncobs, alkali-heated corncobs) on nitrogen removal performance and microbial community structure in CWs for low C/N wastewater.

Biochar and hematite amendments suppress emission of CH and NO in constructed wetlands.

Constructed wetlands (CWs) are considered a widely used cost-effective technology for pollutant removal. However, greenhouse gas emissions are a non-negligible problem in CWs. In this study, four laboratory-scale CWs were established to evaluate the effects of gravel (CW), hematite (CW), biochar (CW), and hematite + biochar (CW) as substrates on pollutants removal, greenhouse gas emissions, and associated microbial characteristics.

[Treatment Effect of Corncob and Rice Straw Enhanced Subsurface Flow Constructed Wetland on Low C/N Ratio Wastewater].

The lack of carbon sources severely inhibits denitrification in wastewater with a low C/N ratio. Corncob and rice straw were chosen as supplementary carbon sources to bring into the wetland system to supplement the carbon sources needed for denitrification, and the enhancing effects of the two carbon sources on nitrogen removal from the wetland were studied. The cumulative release of carbon was in the order of rice straw[(145.