title: Brackish Eutrophic Water Treatment by Iris pseudacorus L.-Planted Microcosms: Physiological Responses of Iris pseudacorus L. to Salinity.
abstract: Iris pseudacorus L. has been widely used in aquatic ecosystem to remove nutrient and has achieved positive effects. However, little is known regarding the nutrient-removal performance and physiological responses of I. pseudacorus for brackish eutrophic water treatment due to high nutrients combined with certain salinity levels. In this study, I. pseudacorus-planted microcosms were established to evaluate the capacity of I. pseudacorus to remove excessive nutrients from fresh (salinity 0.05%) and brackish (salinity 0.5%) eutrophic waters. The degradation of total nitrogen and ammonia nitrogen were not affected by 0.5% salinity; 0.5% salinity promoted the degradation of nitrate nitrogen while severely inhibited the degradation of total phosphorus. Additionally, 0.5% salinity was found to induce stress responses quantified by measuring six physiological indexes. Compared to 0.05% salinity, 0.5% salinity resulted in significant decreases in the chlorophyll a, b and total chlorophyll contents of I. pseudacorus which closely related to photosynthesis (p < 0.05). Furthermore, the higher proline, malondialdehyde contents and antioxidant enzyme activities were detected in I. pseudacorus exposed to 0.5% salinity, which provided protection against reactive oxygen species. The results highlight that the cellular stress assays are efficient for monitoring the health of I. pseudacorus in salinity shock-associated constructed wetlands.
authors.affiliation: a School of Environmental Science and Engineering, Tianjin University , Tianjin , China.
authors.forename: Huilin
authors.initials: H
authors.lastname: Zhao
authors.forename: Fen
authors.initials: F
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Ji
mesh_terms: D063366:Estuaries; D005068:Eutrophication; D031323:Iris Plant / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D000068357:Saline Waters / Q000737:chemistry*; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000737:chemistry*; D012989:Soil Pollutants / Q000378:metabolism*; D013997:Time Factors; D053833:Wetlands
chemical_list: D012989:Soil Pollutants; D010758:Phosphorus; D012965:Sodium Chloride; D009584:Nitrogen
keywords: Iris pseudacorus L.; brackish eutrophic water; nutrients removal; salt stress; stress responses