Mixed Agricultural Pollutant Mitigation Using Woodchip/Pea Gravel and Woodchip/Zeolite Permeable Reactive Interceptors
- 342 Downloads
Dairy soiled water (DSW) is water from concreted areas, hard stand areas and holding areas for livestock that has become contaminated by livestock faeces or urine, chemical fertilisers and parlour washings. Losses of DSW occur as point (e.g. storage, pivot irrigators) and diffuse losses (e.g. during or shortly after land application). The concept of a permeable reactive interceptor (PRI), comprising a denitrifying bioreactor woodchip cell to convert nitrate (NO3 −) to dinitrogen (N2) gas and an adsorptive media cell for phosphorus (P) and ammonium (NH4 +) mitigation, attempts to simultaneously treat mixed pollutants. This study is the first attempt to test this concept at laboratory-scale. Washing of woodchip media prior to PRI operation produced low NO3 − but high NH4 +, dissolved reactive P (DRP) and dissolved organic carbon losses. Dairy soiled water was then treated in replicated PRIs containing woodchip in combination with zeolite or gravel compartments. In general, all PRIs were highly efficient at reducing NO3 −, NH4 +, DRP, dissolved unreactive phosphorus (DUP) and dissolved organic nitrogen (DON) from an influent water replicating DSW. Longitudinal and hydrochemical PRI profiles, as well as zeolite batch experiments, showed that woodchip can both enhance NO3 − reduction and adsorb nutrients. Since woodchip is likely to become saturated, it is important to place the reactive media cell further into the sequence of treatment. Even though the majority of the dissolved nutrients were mitigated, the PRIs also emitted greenhouse gases, which would need further remediation sequences.
KeywordsPermeable reactive interceptor Nitrogen, phosphorus Ammonium Agriculture
This research was supported by the Department of Agriculture Food and Marine under the Project 11/S/152 Improving the productivity of heavy wet grassland for delivery of Food Harvest 2020. The authors would like to thank all staff at Teagasc, Johnstown Castle, Wexford, Ireland for any help given during the duration of the laboratory experiment.
- Anon (2013). Studies on the management and utilisation of soiled water and dilute slurry on Irish farms. Technology Update. Animal and Grassland Research and Innovation. Teagasc. http://www.teagasc.ie/publications/2012/2798/5796.pdf.
- Antonini, S., Paris, S., Eichert, T., & Clemens, J. (2011). Nitrogen and phosphorus recovery from human urine by struvite precipitation and air stripping in Vietnam. Clean: Soil, Air, Water, 39, 1099–1104.Google Scholar
- Fenton, O., Healy, M. G., & Schulte, R. P. O. (2008). A review of remediation and control systems for the treatment of agricultural waste water in Ireland to satisfy the requirements of the Water Framework Directive. Biology and Environment, 108B(2), 69–79.Google Scholar
- Fenton, O., Richards, K. G., Thornton, S., Brennan, F., Healy, M. G., Jahangir, M. M. R., & Ibrahim, T. G. (2014). Permeable reactive interceptors—blocking diffuse nutrient and greenhouse gas losses in key areas of the farming landscape. The Journal of Agricultural Science. Available on CJO2014. doi: 10.1017/S0021859613000944.
- Grubb, K. L., McGrath, J. M., Penn, C. J., Bryant, R. B. (2012). Effect of land application of phosphorus saturated gypsum on soil phosphorus. Applied and Environmental Soil Science. Article ID 506951, & pages, Open Access.Google Scholar
- Haralambous, A., Maliou, E., & Malamis, M. (1992). The use of zeolite for ammonium uptake. Water Science and Technology, 25, 139–145.Google Scholar
- Healy, M. G., Barrett, M., Lanigan, G. J., João Serrenho, A., Ibrahim, T. G., Thornton, S. F., Rolfe, S. A., Huang, W. E., & Fenton, O. (2014). Optimizing nitrate removal and evaluating pollution swapping trade-offs from laboratory denitrification bioreactors. Ecological Engineering, 74, 290–301.CrossRefGoogle Scholar
- McBride, M. B. (2000). Chemisorption and precipitation reactions. In: Sumner ME, editor. Handbook of soil science. Boca Raton, Fl: CRC Press; p. B-265–302.Google Scholar