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Fate of Nitrogen and Phosphorus in a Waste‐water Retention Reservoir Containing Aquatic Macrophytes
Author(s) -
Reddy K. R.
Publication year - 1983
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1983.00472425001200010025x
Subject(s) - macrophyte , eichhornia crassipes , aquatic plant , environmental chemistry , chemistry , microcosm , phosphorus , effluent , eutrophication , nutrient , environmental science , agronomy , environmental engineering , biology , ecology , organic chemistry
Potential use of retention/detention reservoirs stocked with vascular aquatic macrophytes was evaluated, using a microcosm reservoir for reducing the N and P levels of agricultural drainage effluents (waste water). The treatments evaluated were reservoirs stocked with (i) pennywort ( Hydrocotyle umbellata L.), (ii) water hyacinth ( Eichhornia crassipes [Mart] Solms), (iii) cattails ( Typha latifolia L.) and elodea ( Egeria densa P), and (iv) control (no macrophytes). Labeled 15 N was used to differentiate preferential uptake of 15 NH 4 + and 15 NO 3 − , and to follow the fate of added 15 NH 4 + and 15 NO 3 − . Results showed that 34 to 40% of the added inorganic 15 N ( 15 NH 4 + + 15 NO 3 − ) was removed through plant uptake, while 45 to 52% of the added 15 N was unaccounted for, presumably lost through NH 3 volatilization and nitrification‐denitrification processes. In the control reservoir, algal biomass removed 4.4% of added 15 N, while 41% of the added 15 N was not accounted. Pennywort and cattail‐elodea systems were found to be most effective, with about 50% inorganic N removal in a 4‐day detention period. All aquatic macrophytes preferred 15 NH 4 + over 15 NO 3 − , but the difference in uptake was not significant, except for pennywort and cattails, which removed 84 and 92% of the added 15 NH 4 + as compared to 16 and 8% of the added 15 NO 3 − , respectively. About 25 to 29 d were required by the systems with macrophytes to remove 50% of the wastewater P. Plant removal of P was in the range of 3 to 65% of added P, while 7 to 87% of the added P was lost through precipitation and adsorption reactions.