Remediation of algal cells, PO43−, and NO3− from eutrophic wastewater using Echinodorus cordifolius in zigzag-horizontal subsurface constructed wetlands. (15th December 2021)

• Record Type: Journal Article
• Authors: Boonbangkeng, Danuphon; Treesubsuntorn, Chairat; Dolphen, Rujira; Thiravetyan, Paitip
• Is Part Of: Journal of environmental management. Volume 300(2021)
• Publication Date: 2021-12-15
• Subjects: Zigzag baffle -- Effluent recirculation -- Algal cell removal -- Echinodorus cordifolius -- Constructed wetland; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.113720
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The pollutant removal efficiency of traditionally constructed wetlands (CWs) is often limited due to low interaction time between wastewater and the CW matrix (plants, microbes, and substrates). A zigzag-horizontal subsurface flow constructed wetland with effluent recirculation (Z-HSSF + ER) was developed to improve removal efficiency. Echinodorus cordifolius plants were used in this study. The efficiency of the systems was evaluated using eutrophic wastewater. The results showed that the developed systems exhibited the high removal efficiency of algal cells, PO4 3−, and NO3 − (97%, 70%, and 100%, respectively), within 5 days. Algal cells were removed by the interception mechanism of gravel and zigzag baffles. PO4 3− and NO3 − in the eutrophic wastewater was mainly removed by E. cordifolius including rhizobacteria and other microorganisms. The long flow pathway created by the installation of zigzag baffles combined with effluent recirculation provides high dissolved oxygen (DO) in the systems and increases the interaction time between wastewater and the CW matrix, thus improving the pollutant removal efficiency of CWs. Graphical abstract: Image 1 Highlights: Echinodorus cordifolius and microorganisms play an important role in NO3 − and PO4 3− removal. Planted system can remove algal cells, PO4 3− and NO3 − by 97%, 70% and 100%, respectively. Gravel enhanced entrapping algal cells in a zigzag-horizontal subsurface constructed wetland. Zigzag baffles and effluent recirculation enhanced high dissolve oxygen in constructed wetland.