Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater
Groundwater is not only an important component of the hydrologic cycle but also an important drinking water source. Excessive nitrogen fertilizer and organic manure application has caused severe nitrate pollution in groundwater, which threats human health. Bioremediation of groundwater nitrate using...
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Zhejiang University Press
2014-05-01
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| Series: | 浙江大学学报. 农业与生命科学版 |
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| Online Access: | https://www.academax.com/doi/10.3785/j.issn.1008-9209.2013.10.252 |
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| author | Hou Weilong Zhou Hongxiang Shi Jiachun Zeng Lingzao Wu Laosheng |
| author_facet | Hou Weilong Zhou Hongxiang Shi Jiachun Zeng Lingzao Wu Laosheng |
| author_sort | Hou Weilong |
| collection | DOAJ |
| description | Groundwater is not only an important component of the hydrologic cycle but also an important drinking water source. Excessive nitrogen fertilizer and organic manure application has caused severe nitrate pollution in groundwater, which threats human health. Bioremediation of groundwater nitrate using denitrifying forms of bacteria found in groundwater is one of the effective methods for nitrogen removal.Carbon source is one of the necessities for heterotrophic denitrification, and water temperature and hydraulic retention time can also significantly influence the nitrate removal efficiency. The main objectives of this study are to: 1) investigate the performance of denitrification using different single carbon sources;2) evaluate the effects of temperature, hydraulic retention time (HRT) and pH on denitrification performance and screen the best solid carbon source for nitrate removal.This research focused on nitrate removal using commonly available agricultural solid organic residues as the carbon sources. Particularly, corncob, rice straw, and newspaper were employed as the carbon sources for nitrate removal at different temperatures and hydraulic retention times (HRT) in the laboratory.The results indicated that when newspaper was used as carbon source, nitrate concentration was reduced from 30 to around 15 mg/L in 24 hours, and the nitrite concentration was much higher than the standard of the drinking water quality. On the other hand, use of corncob and rice straw as carbon sources could almost completely remove the nitrate within 24 hours. It was observed that small amount of nitrite was accumulated in the denitrification process when corncob and rice straw were used as the carbon sources. Denitrification was markedly affected by temperature. When rice straw and corncob were used as carbon sources, almost 100% nitrate removal was achieved within 60 hours at 20, 25 or 30 ℃, while only 50% nitrate removal could be achieved at 15 ℃. Nitrite concentration increased at first, then decreased to below 0.1 mg/L within 24, 40 and 24 hours, respectively, at 20, 25 and 30℃ when corncob or rice straw was used as carbon source. High nitrate removal efficiency could be achieved at the four different treatments of HRT by using corncob or rice straw as carbon source. But the time required for the nearcomplete removal of nitrate (stable operation) increased with the decrease of HRT.This study indicated that complete nitrate removal can be achieved readily using rice straw or corncob as carbon source by adjusting HRT or temperature in water, which can be potentially implemented in environmental engineering practices. |
| format | Article |
| id | doaj-art-85afd725fb4d4c1d93f2ca67fb98fb49 |
| institution | DOAJ |
| issn | 1008-9209 2097-5155 |
| language | English |
| publishDate | 2014-05-01 |
| publisher | Zhejiang University Press |
| record_format | Article |
| series | 浙江大学学报. 农业与生命科学版 |
| spelling | doaj-art-85afd725fb4d4c1d93f2ca67fb98fb492025-08-20T02:47:32ZengZhejiang University Press浙江大学学报. 农业与生命科学版1008-92092097-51552014-05-014031432110.3785/j.issn.1008-9209.2013.10.25210089209Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwaterHou WeilongZhou HongxiangShi JiachunZeng LingzaoWu LaoshengGroundwater is not only an important component of the hydrologic cycle but also an important drinking water source. Excessive nitrogen fertilizer and organic manure application has caused severe nitrate pollution in groundwater, which threats human health. Bioremediation of groundwater nitrate using denitrifying forms of bacteria found in groundwater is one of the effective methods for nitrogen removal.Carbon source is one of the necessities for heterotrophic denitrification, and water temperature and hydraulic retention time can also significantly influence the nitrate removal efficiency. The main objectives of this study are to: 1) investigate the performance of denitrification using different single carbon sources;2) evaluate the effects of temperature, hydraulic retention time (HRT) and pH on denitrification performance and screen the best solid carbon source for nitrate removal.This research focused on nitrate removal using commonly available agricultural solid organic residues as the carbon sources. Particularly, corncob, rice straw, and newspaper were employed as the carbon sources for nitrate removal at different temperatures and hydraulic retention times (HRT) in the laboratory.The results indicated that when newspaper was used as carbon source, nitrate concentration was reduced from 30 to around 15 mg/L in 24 hours, and the nitrite concentration was much higher than the standard of the drinking water quality. On the other hand, use of corncob and rice straw as carbon sources could almost completely remove the nitrate within 24 hours. It was observed that small amount of nitrite was accumulated in the denitrification process when corncob and rice straw were used as the carbon sources. Denitrification was markedly affected by temperature. When rice straw and corncob were used as carbon sources, almost 100% nitrate removal was achieved within 60 hours at 20, 25 or 30 ℃, while only 50% nitrate removal could be achieved at 15 ℃. Nitrite concentration increased at first, then decreased to below 0.1 mg/L within 24, 40 and 24 hours, respectively, at 20, 25 and 30℃ when corncob or rice straw was used as carbon source. High nitrate removal efficiency could be achieved at the four different treatments of HRT by using corncob or rice straw as carbon source. But the time required for the nearcomplete removal of nitrate (stable operation) increased with the decrease of HRT.This study indicated that complete nitrate removal can be achieved readily using rice straw or corncob as carbon source by adjusting HRT or temperature in water, which can be potentially implemented in environmental engineering practices.https://www.academax.com/doi/10.3785/j.issn.1008-9209.2013.10.252groundwaternitrate removalcarbon sourcetemperaturehydraulic retention time |
| spellingShingle | Hou Weilong Zhou Hongxiang Shi Jiachun Zeng Lingzao Wu Laosheng Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater 浙江大学学报. 农业与生命科学版 groundwater nitrate removal carbon source temperature hydraulic retention time |
| title | Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater |
| title_full | Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater |
| title_fullStr | Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater |
| title_full_unstemmed | Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater |
| title_short | Effects of carbon sources, temperature and hydraulic retention time on nitrate removal from groundwater |
| title_sort | effects of carbon sources temperature and hydraulic retention time on nitrate removal from groundwater |
| topic | groundwater nitrate removal carbon source temperature hydraulic retention time |
| url | https://www.academax.com/doi/10.3785/j.issn.1008-9209.2013.10.252 |
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