Enhanced Nitrogen Removal of Eutrophic Water in Constructed Wetland by Novel Integration of Submerged Macrophyte Pond

Abstract

Nitrogen pollution exacerbated water eutrophication and thus caused the rapid growth of algae. Constructed wetland (CW) could be blocked by excessive algae when removing nitrogen from eutrophic water. Submerged macrophytes were proved to be effective in decreasing algae survival and purifying nitrogen compounds. Therefore, submerged macrophyte pond (SMP) was integrated with CW to enhance nitrogen removal through intensifying nitrification and denitrification simultaneously.In hybrid system, algae-macrophyte photosynthesis in SMP improved oxygen environment of subsequent CW, thus facilitating nitrification process of CW. Residual algae debris from SMP effluents could be utilized as biodegradable carbon sources for subsequent CW, thus promoting denitrification process of CW. Nitrogen removal performance in hybrid system was significantly higher than that in single SMP and CW reactor due to carbon and oxygen enhancement, and the highest NH 4 -N and TN removals reached 62.1±2.0% and 60.4±2.0%. The layer effect on nitrogen removal had been identified in CW unit, and optimal reductions of NH 4 -N and TN were obtained in the upper and bottom layer respectively. The study suggested that the hybrid system could be a cost-effective solution for reducing nitrogen and algae loads of eutrophic water.

Effects of Sediment Types and Planting Density on the Plant Trait of <i>Myriophyllum spicatum</i>

“…It is highly valued in the field of water treatment due to its ability to produce a large amount of biomass and its fast growth rate. Both domestic and international research on M. spicatum in water treatment primary focuses on four areas: biosorption, biodegradation, bioenergy utilization and ecotoxicology [19][20][21][22]. One key aspect of M. spicatum that is of interest in water treatment is its ability to adsorb heavy metals and organic pollutants.…”

“…In summary, research involving M. spicatum extends beyond its adsorption capabilities, encompassing the potential for biofuel production, ecotoxicology assessment, and water pollution evaluation. The versatility and adaptability of M. spicatum make it an attractive candidate for multiple applications in the field of water treatment and ecological restoration [19][20][21][22].…”

Enhanced Nitrogen Removal Performance in Constructed Wetland by Coupling Partial Tide Flow Operation Mode with Iron-Carbon Micro-Electrolysis Process

“…The depletion of oxygen and electron donor due to wetland configuration and low C/N characteristic of wastewater led to incomplete total nitrogen (TN) removal efficiency in traditional CWs [7]. Although external carbon addition and artificial aeration strategies have been proven effective in supplementing carbon sources and oxygen, both strategies are high-cost and unsuitable for long-term utilization [8]. It is imperative to develop an economic strategy to promote CW performance for permanent applications.…”