Selection and application of agricultural wastes as solid carbon sources and biofilm carriers in MBR

• Published in: Journal of hazardous materials Vol. 283; pp. 186 - 192
• Main Authors: Yang, Xiao-Li, Jiang, Qi, Song, Hai-Liang, Gu, Tian-Tian, Xia, Ming-Qian
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2015
• Subjects: Agricultural wastes; Agriculture; Biodegradation, Environmental; Biofilm carrier; Biofilms; Bioreactors; Carbon; Carbon/nitrogen ratio; Denitrification; Feasibility; Leaching; Nitrates; Nitrogen; Oryza sativa; Solid carbon source; Straw; Surface properties; Triticum aestivum; Waste Water - chemistry; Water Purification - methods; Wheat; Denitrification; Solid carbon source; Biofilm carrier; Carbon/nitrogen ratio; Agricultural wastes
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.09.036

•Agricultural wastes can be used as carbon sources and biological carriers.•The effluent COD presented a slight increase but within an acceptable level.•Mixed liquor and microbial activity were not influenced by agricultural wastes.•Rice straw was proven to be most effective in improving TN removal.
This paper examined the feasibility of agricultural wastes used as solid carbon sources and the effect of determined agricultural wastes on improving denitrification. Eight agricultural wastes were evaluated in MBR tests to find out their carbon release capacity, denitrification potential, leaching elements and surface properties. The results showed that retinervus luffae fructus, wheat straw, corncob and rice straw had higher carbon release capacity with COD of 13.17–21.07mgg−1day−1, BOD5 of 3.33–7.33mgg−1day−1 and respirable carbon of 8.64–10.71mgg−1day−1. Correspondingly, they displayed a good denitrification potential of 105.3–140.1mg NO3−–Ng−1. Rice straw, retinervus luffae fructus and corncob were then applied in MBRs. These three agricultural wastes were found to be effective in enhancing the denitrification process, where the TN removal increased from 43.44% (control MBR) to 82.34, 68.92 and 62.97%, respectively.