Phosphorus removal by periphyton developed on the artificial substrate in the hypereutrophic pond

Abstract

Last decades of the 20th century faced us with the extensive eutrophication of aquatic ecosystems, which is one of the most serious environmental issues. Excessive phosphorus inflow is recognized as a key factor that causes this phenomenon. Shallow stagnant waters are particularly vulnerable to eutrophication that leads to their significant degradation and biodiversity loss. Plenty of methods have been proposed to remove the phosphorus from the water column so far. In this study, the potential of the biological method using periphyton developed on the artificial substrate in the hypereutrophic pond has been investigated. The artificial substrate carrier was submerged from May to October and samples were collected both continuously incubated (from the start of carrier exposure) and monthly developed. Qualitative and quantitative analyses of autotrophic periphyton component were done, and Autotrophic and Lakatos indices were calculated to describe the community. Total phosphorus content in periphyton was estimated spectrophotometrically. The investigated community was characterized as abundantly developed, inorganic and predominantly heterotrophic. The autotrophic component was dominated by Bacillariophyta with a low share of Cyanobacteria in total biomass. Those periphyton characteristics caused maximal phosphorus assimilation of 14.68 mg P/m2 only, after three-month exposure, but 12.66 mg P/m2 in the monthly sample in August. Obtained results indicate that considering such periphyton structure, employing the monthly developed communities in phosphorus harvesting during the remediation process could be more effective than using the continuous ones. At the same time, the potential large-scale employment of this approach would affect the existing biocoenosis to a lesser extent.