Effectiveness of the tropical plants Rhynchospora corymbosa and Coix lacryma-jobi in vertical flow constructed wetlands for municipal primary sewage effluent treatment

Abstract

The performance of two tropical plants, Rhynchospora corymbosa L. (RC) and Coix lacryma-jobi, L (CL) in treatment of primary sewage effluent in lab-scale vertical-flow constructed wetlands (VFCW) along with no plant control wetland was investigated. A batch-flow VFCWs were operated under batch fill and drain hydraulic loading system with hydraulic retention times (HRT) of 0.5, 1, and 2 days and fill rate of 8 L/day. Removal of solids, organics, nutrients, and pathogens were monitored. The volumetric contaminant removal rates were best described by 1st order kinetics except for ammonia and phosphate, which was best described by Stover-Kincannon kinetics. Influent TSS, PO₄³⁻, COD, BOD₅, and total coliform concentration were low but high in NH₄⁺ concentration. CL was better in nutrient removal as HRT increases compared to RC. RC was more efficient at TSS, turbidity, and organics removal. Pathogen removal was independent of plant type but HRT. Solids and organic removal were lower in CL planted CWs due to preferential flow paths created by their bulky root. CL planted CWs removed more nutrients followed by RC planted CWs and then no-plant control CWs. The results of these tests demonstrate that both CL and RC are suitable for the treatment of municipal wastewater in VFCW system.

Keywords:

• Coix lacryma-jobi L
• coliform removal
• constructed wetland
• hydraulic retention time
• primary sewage
• Rhynchospora corymbose L

View correction statement:

Correction

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article was originally published with errors, which have now been corrected in the online version. Please see Correction (http://dx.doi.org/10.1080/15226514.2023.2197332).

Additional information

Funding

Funding was provided by a grant from the National Science Foundation’s Division of Chemical, Bioengineering, Environmental and Transport Systems-Environmental Health and Safety of Nanotechnology program (#1067572). Additional funding for Dr. Ewemoje was provided by the Fulbright Junior Staff Development (JSD) Program and the Institute for International Education (IIE), New York.