Nitrogen Dynamics and Removal by Algal Turf Scrubber under High Ammonia and Organic Matter Loading in a Recirculating Aquaculture System

Authors: Joshua S. Valeta, Marc C. Verdegem

Abstract:

A study was undertaken to assess the potential of an Algal Turf Scrubber to remove nitrogen from aquaculture effluent to reduce environmental pollution. High total ammonia nitrogen concentrations were introduced to an Algal Turf Scrubber developed under varying hydraulic surface loading rates of African catfish (Clarius gariepinus) effluent in a recirculating aquaculture system. Nutrient removal rates were not affected at total suspended solids concentration of up to 0.04g TSS/l (P > 0.05). Nitrogen removal rates 0.93-0.99g TAN/m²/d were recorded at very high loading rates 3.76-3.81 g TAN/m²/d. Total ammonia removal showed ½ order kinetics between 1.6 to 2.3mg/l Total Ammonia Nitrogen concentrations. Nitrogen removal increased with its loading, which increased with hydraulic surface loading rate. Total Ammonia Nitrogen removal by Algal turf scrubber was higher than reported values for fluidized bed filters and trickling filters. The algal turf scrubber also effectively removed nitrate thereby reducing the need for water exchange.

Keywords: Algal turf, loading rate, nitrogen, organic matter, removal rate.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1329318

References:

[1] Smith, V.H. (2003). Euttrophication of freshwater and coastal marine ecosystems. A global problem. Environ.Sci. & Pollut. Res.10(2), 126- 139.
[2] Sereti, V., L. Sfetcu, H. Huizing, M.C.J. Verdegem, E. Eding and J.A.J. Verreth, (2005). The potential of a periphyton reactor to maintain thewater quality in recirculating aquaculture systems. Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Wageningen University and Research Center, P.O.B. 338, 6700 AH, Wageningen, The Netherlands.
[3] Verdegem, M.C.J., Eding, E.H., Sereti, V., Munubi, R.N., Santacruz- Reyes and A.A. van Dam (2005). Similarities between microbial and periphytic biofilms in aquaculture Systems. Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Wageningen University and Research Center, P.O.B. 338, 6700 AH, Wageningen, The Netherlands.
[4] Parent, S., Morin A., (2000). N budget as water quality management tool in closed aquatic mesocosms. Water research 34, no. 6, pp.1846-1856.
[5] Huizing, H., (2004). Periphyton reactor for nutrient retention and maintenance of water quality in recirculating aquaculture system. MSc. Thesis. Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Wageningen University and Research Center, P.O.B. 338, 6700 AH, Wageningen, The Netherlands.
[6] Davis, L.S, Hoffmann, J.P., Cook, P.W. (1990). Production and nutrient accumulation by periphyton in wastewater treatment facility. J. Phycol.26, 617-623
[7] Brix, H. and Schierup, H.H. (1989). The use of aquatic macrophytes in water pollution control. Ambio 18, 101-107.
[8] Korner, S., Vermaat, J.E. and Veenstra, S. (2003). The capacity of duckweed to treat wastewater: ecological considerations for a sound design. Journal of Environmental Quality 32, 1583-1590.
[9] Toet, S., Hersbach, L. and Verhoeven, J.T.A. (2003). Periphyton biomass and nutrient dynamics in a treatment wetland in relation to substratum, hydraulic retention time and nutrient removal. Archive der Hydrobiologie-Supplement, 139, 361-392.
[10] APHA (1998). Standard Methods for the examination of water and wastewater. American Public Health Association, Washington, DC.
[11] Muir, J.F. (1982). Recirculated Water Systems in Aquaculture. In: Muir, J.F., Roberts, R.J., (Eds), Recent Advances in Aquaculture. Croom Helm, London, pp. 357-447.
[12] Skjolstrup, J., Nielsen, P.H., Frier, J.O., McLean, E., (1998). Performance characteristics of fluidized bed bioflters in a novel laboratory-scale recirculation system for rainbow trout: nitrification rates, oxygen consumption and sludge collection. Aquacult. Eng. 18, 265-276.
[13] Bovendeur, J. (1989). Fixed-Biofilm reactors applied to wastewater treatment and aquacultural water recirculating systems. PhD. Thesis, Wageningen University, Wageningen.
[14] Van Rijn, J., Rivera, G. (1990). Aerobic and anaerobic biofiltration in an aquaculture unit-Nitrite accumulation as a result of nitrification and denitrification. Aquacult. Eng. 9, 217-234.
[15] Pizzaro, C., Kebede-Westhead, E., Mulbry, W. 2002. Nitrogen and phosphorus removal rates using small algal turfs grown with dairy manure. J. Appli. Phycol. 14, 469-473.
[16] Leclercq, D.I., Hopkins, K. (1985). Preliminary test of an aerated tank system for tilapia culture. Aquacult. Eng. 4, 229-304.
[17] Ridha, M.T., Cruz, E.M. (2001). Effect of biofilter media on water quality and biological performance of the Nile Tilapia Oreochromis niloticus L. reared in a simple recirculation system. Aquacult. Eng. 24, 157-166.
[18] Valeta J.S., (2006). Purification of aquaculture effluents using algal turf scruber technology. MSc. Thesis. Aquaculture and Fisheries Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Wageningen University and Research Center, P.O.B. 338, 6700 AH, Wageningen, The Netherlands.
[19] Zhu, S. and Chen, S. (2001). Effects of organic carbon on nitrification rate in fixed biofilm biofilters. Aquacultural Engineering 25, 1-11.
[20] Syrett, P.J., (1981). Nitrogen metabolism of microalgae. Can. Bull. Fish. Aquat. Sci. 210, 182-210.