Effects of applying different carbon substrates on nutrient removal and greenhouse gas emissions by constructed wetlands treating carbon-depleted hydroponic wastewater. (August 2022)

• Record Type: Journal Article
• Authors: Zhou, Tongtong; Liu, Jiangong; Lie, Zhiyang; Lai, Derrick Y.F.
• Is Part Of: Bioresource technology. Volume 357(2022)
• Publication Date: 2022-08
• Subjects: Hydroponic wastewater -- Constructed wetlands -- Plant litter -- Nitrogen removal; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.127312
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Addition of carbon substrates improved nutrient removal efficiency of VFCWs. Addition of sucrose and reed litter performed equally well in nutrient removal. Kale residues decomposed rapidly and reduced nutrient efficiency of VFCWs. Addition of kale residues caused higher CH4 and N2 O emissions than reed litter. Phragmites litter is an effective, low-cost and climate-friendly carbon substrate. Abstract: The addition of external carbon sources is crucial for effective biological treatment of nutrient-rich but carbon-depleted hydroponic wastewater using constructed wetlands. In this study, we examined the effects of applying three types of carbon substrates, namely sucrose, hydroponic kale residues, and common reed litter, on the nutrient removal efficiency and greenhouse gas emission rate of vertical flow constructed wetlands. The addition of sucrose and common reed litter was shown to perform equally well in enhancing the removal of total nitrogen (84.9–93.5%), nitrate (98.3–99.8%) and phosphate (53.8–55.2%) as compared to the control. Moreover, the application of common reed litter led to significantly lower mean CH4 and N2 O emissions than that of kale residues. These findings suggested that Phragmites reed litter, which is easily found in wetlands worldwide, could be an effective, low-cost and climate-friendly carbon substrate to be applied in constructed wetlands for hydroponic wastewater treatment.