The performance of pyrite-based autotrophic denitrification column for permeable reactive barrier under natural environment

• Published in: Bioresource technology Vol. 290; p. 121763
• Main Authors: Xu, Baokun, Shi, Liangsheng, Zhong, Hua, Wang, Kang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2019
• Subjects: Autotrophic denitrification; NO3−-N removal; Pyrite; Temperature; NO3−-N removal; Temperature; Autotrophic denitrification; Pyrite; NO(−)-N removal
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121763

[Display omitted] •The effect of temperature drop on pyrite-based denitrification was investigated.•The temperature had larger influence on denitrification than substances addition.•The reduction of NO2−-N was more sensitive to temperature drop (T > 20 °C).•The conversion of NO3−-N to NO2−-N was more sensitive to temperature drop (T < 20 °C).•The electron contribution of pyrite changed slightly as temperature decreased. The effect of temperature on pyrite-based autotrophic denitrification performance and conversion between N species under natural conditions was investigated by using dynamic-flow column experiment. Phosphate and bicarbonate were added trying to enhance denitrification performance when the temperature decreased to 20 °C. However, the temperature had a much more sensitive influence on the denitrification process than substances addition. NO3−-N removal efficiency decreased with the decrease of temperature. When the temperature was higher than 20 °C, the NO2−-N reduction process was more sensitive to the temperature drop, while the process of NO3−-N to NO2−-N was more sensitive to temperature drop when the temperature was lower than 20 °C. The different influence of temperature drop on the two processes led to changes of the distribution of NO3−-N, NO2−-N, and SO42−-S along the column. However, the electron contribution of pyrite among the electron donors only changed slightly.