Phytoremediation performance of floating treatment wetlands with pelletized mine water sludge for synthetic greywater treatment

Suhail N Abed; Suhad A Almuktar; Miklas Scholz

doi:10.1007/s40201-019-00372-z

Phytoremediation performance of floating treatment wetlands with pelletized mine water sludge for synthetic greywater treatment

J Environ Health Sci Eng. 2019 Apr 18;17(2):581-608. doi: 10.1007/s40201-019-00372-z. eCollection 2019 Dec.

Authors

Suhail N Abed¹, Suhad A Almuktar^{1

2}, Miklas Scholz^{1

3

4}

Affiliations

¹ 1Civil Engineering Research Group, School of Computing, Science and Engineering, The University of Salford, Newton Building, Salford, England M5 4WT UK.
² 2Department of Architectural Engineering, Faculty of Engineering, The University of Basrah, Al-Basrah, Iraq.
³ 3Division of Water Resources Engineering, Department of Building and Environmental Technology, Faculty of Engineering, Lund University, P.O. Box 118, 221 00 Lund, Sweden.
⁴ 4Department of Civil Engineering Science, School of Civil Engineering and the Built Environment, University of Johannesburg, Kingsway Campus, PO Box 524, Aukland Park, Johannesburg 2006 South Africa.

Abstract

Purpose: Buckets containing floating reed (Phragmites australis) simulated floating treatment wetlands (FTWs) and were used to improve the remediation performance of synthetic greywater (SGW). The aim of the study was to investigate the behaviour of FTWs for treatment of key contaminants within artificial greywater.

Methods: Pelletized ochre based on acid mine water sludge was introduced to selected FTWs, because of its capability in sequestration phosphorus and other trace elements. The impact of the following four operational variables were tested in the experimental set-ups of the FTWs (four replicates each): pollutant strength (high- (HC) and low- (LC) concentrations), treatment time (2- or 7-days of hydraulic retention time (HRT)), presence or absence of macrophytes (P. australis) and cement-ochre pellets.

Results: The results showed that 5 - day biochemical oxygen demand (BOD) and chemical oxygen demands (COD) were significantly (p < 0.05) reduced in all wetlands. Nitrate-nitrogen (NO₃-N) concentrations were significantly (p < 0.05) higher, and those measurements for PO₄-P were significantly (p < 0.05) lower than the corresponding ones determined for the influent. The existence of ochre pellets with P. australis significantly (p < 0.05) decreased B, Cd, Cr, Cu, Mg, Ni and Zn concentrations, but increased Al, Ca, Fe and K concentrations in the effluent, with the exception of sodium (Na).

Conclusions: The FTW performances can be improved by utilising ochre-cement pellets to increase the pH of greywater. The presence of P. australis acts as a buffer to neutralise the pH of SGW. Rhizomes and biofilms mitigate increases in turbidity, TSS and colour values.

Keywords: Eco–technology; Ferric oxide; Nutrient; Phragmites australis; Phytoremediation; Trace element.