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Biological Denitrification Using Corncobs as a Carbon Source and Biofilm Carrier
Author(s) -
Xu Zuxin,
Shao Liu,
Yin Hailong,
Chu Huaqiang,
Yao Yijun
Publication year - 2009
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143008x325683
Subject(s) - nitrate , denitrification , nitrite , chemistry , wastewater , environmental chemistry , carbon source , environmental engineering , carbon fibers , nitrogen , pulp and paper industry , nuclear chemistry , environmental science , biochemistry , materials science , organic chemistry , composite number , composite material , engineering
In this research, agricultural waste—in particular, corncobs—was investigated for use as the sole carbon source and biofilm carrier to remove nitrate from wastewater in up‐flow laboratory reactors. An artificial wastewater with a temperature range of 27 to 33°C was used. Fast startup of the reactor and a high nitrate removal efficiency were observed. The highest denitrification rate of 0.203kg/(m 3 · d) was achieved when flow rate and nitrate concentration were 153 L/d and 25.3 mgN/L, respectively. The accumulation of nitrite was not observed in this process. Moreover, flow rate and nitrate concentration of the influent were observed to have a significant effect on nitrate removal efficiency. A sharp decline of nitrate removal efficiency was observed when the flow rate was greater than 50 L/d. The reactor had the ability to accommodate a wide range of pH levels (6.5 to 8.5) and dissolved oxygen (1.5 mg/L to 4 mg/L). A time‐dependent decrease in nitrate removal efficiency was observed after 67 days of operation. The addition of fresh corncobs brought about a rapid increase of nitrate removal efficiency. Results showed that corncobs could be used as an economical and effective carbon source for denitrification.