Nitrate removal from tile drainage water: The performance of denitrifying woodchip bioreactors amended with activated carbon and flaxseed cake

In this paper, a study on using fixed-film biological denitrification to remove nitrates from water supplies is reported. Fixed-film biological systems have not been used in water supply systems in the U.S. although they are proven to be efficient and economical for removing nitrates with the reason being the possibility of imparting residual organics, suspended solids and bacteria to the treated water. In this research, fixed-film upflow biodenitrification columns were operated under carbon-starved conditions and the effluent was treated with a granular activated carbon (GAC) and sand filter system (combined in one unit) to remove residual organics and suspended matter. The system resulted in an average effluent turbidity of 0.8 NTU, and COD and total suspended solids (TSS) concentrations of 5.7 and 0.6 mg/L, respectively.

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Enhanced nitrate removal by micro-electrolysis using Fe0 and surfactant modified activated carbon

Chemical Engineering Journal ◽

10.1016/j.cej.2018.09.071 ◽

2019 ◽

Vol 357 ◽

pp. 180-187 ◽

Cited By ~ 22

Author(s):

Lianggen Ao ◽

Fan Xia ◽

Yang Ren ◽

Jian Xu ◽

Dezhi Shi ◽

...

Keyword(s):

Activated Carbon ◽

Nitrate Removal ◽

Modified Activated Carbon

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Effect of controlled drainage and tillage on soil structure and tile drainage nitrate loss at the field scale

Water Science & Technology ◽

10.2166/wst.1998.0593 ◽

1998 ◽

Vol 38 (4-5) ◽

pp. 103-110 ◽

Cited By ~ 24

Author(s):

C. S. Tan ◽

C. F. Drury ◽

M. Soultani ◽

I. J. van Wesenbeeck ◽

H. Y. F. Ng ◽

...

Keyword(s):

Soil Structure ◽

Conservation Tillage ◽

Drainage System ◽

Conventional Tillage ◽

Drainage Water ◽

Tile Drainage ◽

No Tillage ◽

Controlled Drainage ◽

Nitrate Loss ◽

Free Drainage

Conservation tillage has become an attractive form of agricultural management practices for corn and soybean production on heavy textured soil in southern Ontario because of the potential for improving soil quality. A controlled drainage system combined with conservation tillage practices has also been reported to improve water quality. In Southwestern Ontario, field scale on farm demonstration sites were established in a paired watershed (no-tillage vs. conventional tillage) on clay loam soil to study the effect of tillage system on soil structure and water quality. The sites included controlled drainage and free drainage systems to monitor their effect on nitrate loss in the tile drainage water. Soil structure, organic matter content and water storage in the soil profile were improved with no-tillage (NT) compared to conventional tillage (CT). No-tillage also increased earthworm populations. No-tillage was found to have higher tile drainage volume and nitrate loss which were attributed to an increase in soil macropores from earthworm activity. The controlled drainage system (CD) reduced nitrate loss in tile drainage water by 14% on CT site and 25.5% on NT site compared to the corresponding free drainage system (DR) from May, 1995 to April 30, 1997. No-tillage farming practices are definitely enhanced by using a controlled drainage system for preventing excessive nitrate leaching through tile drainage. Average soybean yields for CT site were about 12 to 14% greater than the NT site in 1995 and 1996. However, drainage systems had very little effect on soybean yields in 1995 and 1996 due to extremely dry growing seasons.

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Experimental effect of medium ratio on removal efficiency of nitrate nitrogen in groundwater by zero-valent iron, activated carbon and zeolite

Water Science & Technology Water Supply ◽

10.2166/ws.2019.036 ◽

2019 ◽

Vol 19 (6) ◽

pp. 1636-1642

Author(s):

Sizhi Cao ◽

Peigui Liu ◽

Mingchao Liu ◽

Gang Wang ◽

Zaili Li ◽

...

Keyword(s):

Activated Carbon ◽

Nitrate Nitrogen ◽

Nitrogen Concentration ◽

Nitrate Removal ◽

Ammonia Nitrogen ◽

Coarse Sand ◽

Zero Valent Iron ◽

Nitrite Nitrogen ◽

Rich Solution ◽

Set Up

Abstract In this study, column experiments in the laboratory were set up to examine how the concentrations of nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen changed when a nitrate-rich solution was passed through a medium comprising zero-valent iron, activated carbon, zeolite, and coarse sand. We varied the proportions of the components of the medium to determine how it influenced the nitrate removal and nitrogen fractions. Three different scenarios were used, with: (1) iron, activated carbon, and coarse sand at a ratio of 3:1:6; (2) iron, activated carbon, and zeolite at a ratio of 3:1:6; and (3) iron, activated carbon, and zeolite at a ratio of 3:3:4. The nitrate nitrogen concentration decreased from 25 mg/L to 2 mg/L in the first scenario. Removal was better when zeolite was added to the medium as most of the nitrate nitrogen broke down to ammonia nitrogen, with nitrite nitrogen as an intermediate product. The results of the tests showed that nitrate removal was best when the medium was iron, activated carbon, and zeolite, mixed at a ratio of 3:1:6. This study provides a scientific reference for in situ remediation of nitrate pollution in groundwater.

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Survival of Escherichia coli in agricultural soil and presence in tile drainage and shallow groundwater

Canadian Journal of Soil Science ◽

10.4141/cjss09113 ◽

2010 ◽

Vol 90 (3) ◽

pp. 495-505 ◽

Cited By ~ 14

Author(s):

A C VanderZaag ◽

K J Campbell ◽

R C Jamieson ◽

A C Sinclair ◽

L G Hynes

Keyword(s):

Escherichia Coli ◽

Fecal Contamination ◽

Shallow Groundwater ◽

Drainage Water ◽

Tile Drainage ◽

Subsurface Water ◽

Bacterial Survival ◽

Manure Application ◽

Monitoring Wells ◽

E Coli

Animal agriculture and the use of manure as a soil amendment can lead to enteric pathogens entering water used for drinking, irrigation, and recreation. The presence of Escherichia coli in water is commonly used as an indicator of recent fecal contamination; however, a few recent studies suggest some E. coli populations are able to survive for extended time periods in agricultural soils. This important finding needs to be further assessed with field-scale studies. To this end, we conducted a 1-yr study within a 9.6-ha field that had received fertilizer and semi-solid dairy cattle manure annually for the past decade. Escherichia coli concentrations were monitored throughout the year (before and after manure application) in the effluent from tile drains (at approximately 80 cm depth) and in 5- to 8-m-deep groundwater wells. Escherichia coli was detected in both groundwater and tile drain effluent at concentrations exceeding irrigation and recreational water-quality guidelines. Within two of the monitoring wells, concentrations of E. coli, and frequency of detections, were greatest several months after the manure application. In two monitoring wells and one tile drain the frequency of E. coli detections was higher before manure was applied than after. This suggests the presence and abundance of E. coli was not strongly related to the timing of manure application. A laboratory study using naladixic acid resistant E. coli showed the bacteria could survive at least two times longer in soil samples collected from the study field than in soil from the adjacent riparian area, which had not received manure applications. Together, field and lab results suggest that a consistent source of E. coli exists within the field, which may include “naturalized” strains of E. coli. Further studies are required to determine the specific source of E. coli detected in tile drainage water and shallow groundwater. If the E. coli recovered in subsurface water is primarily mobilized from naturalized populations residing within the soil profile, this indicator organism would have little value as an indicator of recent fecal contamination. Key words: Bacterial survival, naturalized Escherichia coli, groundwater, tile drainage

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