Comparison of agricultural wastes and synthetic macromolecules as solid carbon source in treating low carbon nitrogen wastewater

Rui Xiong; Xinxiao Yu; Yonge Zhang; Zhaoxu Peng; Luji Yu; Lulu Cheng; Tingmei Li

doi:10.1016/j.scitotenv.2020.139885

Comparison of agricultural wastes and synthetic macromolecules as solid carbon source in treating low carbon nitrogen wastewater

Sci Total Environ. 2020 Oct 15:739:139885. doi: 10.1016/j.scitotenv.2020.139885. Epub 2020 Jun 5.

Authors

Rui Xiong¹, Xinxiao Yu², Yonge Zhang³, Zhaoxu Peng⁴, Luji Yu⁴, Lulu Cheng⁴, Tingmei Li⁵

Affiliations

¹ Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
² Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China. Electronic address: yuxinxiao111@126.com.
³ Institute of Sediment Research, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
⁴ School of Water Conservancy & Environment, Zhengzhou University, Zhengzhou 450001, China.
⁵ Research Center for Environmental Policy Planning & Assessment of Zhengzhou University, Zhengzhou 450002, China.

PMID: 32534311
DOI: 10.1016/j.scitotenv.2020.139885

Abstract

This paper investigated the feasibility of using agricultural wastes and synthetic macromolecules as solid carbon sources and studied the effects of improvement of denitrification by the selected agricultural wastes. The carbon release capacity and denitrification performance of corncob (CC), peanut shell (PS), obsolescent rice (OR) and polycaprolactone (PCL), poly butylene succinate (PBS), polyvinyl alcohol sodium alginate (PVA-SA) were systematically analyzed. The results showed that for each carbon source, the first-order kinetic equation was basically followed during the carbon release process. PVA-SA, CC and PS had higher carbon release capacity with accumulative dissolved organic carbon (DOC) of 16.22-20.63 mg·g^-1 and chemical oxygen demand (COD) of 100.86-134.10 mg·g^-1. Correspondingly, they showed excellent denitrification performance with almost no residual NO₃^--N, and the denitrification process well followed the Monod equation. PCL, PBS and OR had lower carbon release capacity with accumulative DOC of 2.06-3.14 mg·g^-1 and COD of 13.29-24.13 mg·g^-1, respectively. Nevertheless, these materials can also improve the denitrification performance, with the residual NO₃^--N in the range of 6.02-6.36 mg·L^-1, and the effluent DOC was in the range of 10-15 mg·L^-1. Synthetic polymers are more suitable for nitrogen removal in groundwater treatment, while agricultural wastes are ideal carbon sources for secondary effluent treatment.

Keywords: Agricultural wastes; Carbon source; Denitrification; Kinetic.