LiRongji,NieZhengxin,CaoXian,et al.Effect of Different Solid Slow-release Carbon Sources on Nitrogen Removal from Low Carbon-to-Nitrogen Ratio Wastewater[J].China Water & Wastewater,2026,42(13):63-68.
Effect of Different Solid Slow-release Carbon Sources on Nitrogen Removal from Low Carbon-to-Nitrogen Ratio Wastewater
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第42卷
Number:
第13期
Page:
63-68
Column:
Date of publication:
2026-07-01
- Keywords:
- solid slow-release carbon source; corn cob; denitrification; low carbon-to-nitrogen ratio; carbon release capacity
- Abstract:
- To improve the poor biodegradability caused by a low carbon-to-nitrogen (C/N) ratio in wastewater, this study investigated the carbon release capacity and denitrification performance of polylactic acid (PLA) particles, corn cob, and alkali-treated corn cob as solid slow-release carbon sources. The average COD release rates of the three carbon sources were 0.22 mg/(g·d), 1.18 mg/(g·d) and 1.40 mg/(g·d), respectively, and their nitrate nitrogen removal rates reached 37.0%, 74.4%, and 88.4%, respectively. Three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy analysis revealed two distinct fluorescence peaks for both corn cob and alkali-treated corn cob in the range of 280-360 nm, with the alkali-treated group exhibiting higher fluorescence intensity, indicating a stronger organic matter release capacity. Scanning electron microscopy (SEM) results showed that the surface structure of alkali-treated corn cob was more favorable for microbial attachment. The three carbon sources were respectively added to the denitrification tank to investigate their promoting effects on denitrification of low C/N wastewater and their impact on effluent quality. The results showed that with increasing dosage, PLA, corn cob, and alkali-treated corn cob all effectively enhanced the TN removal efficiency of the natural aeration biofilter process. The C/N ratio at each treatment stage improved, and the effluent concentrations of COD and TN both met the discharge standards. Considering cost factors, corn cob has greater application prospects as an external solid slow-release carbon source for the treatment of low C/N ratio wastewater in rural areas.
Last Update:
2026-07-01