Comparison of heavy metal and nutrients removal in and based constructed wetlands for piggery effluent treatment in north-central Nigeria.

Batch-fed horizontal sub-surface flow constructed wetlands (HssFCW) were developed to compare the potential of C and in removing heavy metals and nutrients from piggery effluent. Piggery effluent samples were characterized for nutrients (N and P) and metals (Mg, Al, Ca and Fe) before and after introducing them to the HssFCW with hydraulic retention time (HRT) of 3 days and operational flowrate of 0.014 m/day. Three sets of constructed wetlands (CWs) were monitored during the dry season for 3 months. The bioconcentration factor (BCF) and translocation factor (TF) for the plants were evaluated. The results were all significantly different at  ≤ 0.05. removes more nutrients and metals than . The BCF for . was higher than for while the TF was higher for indicating a higher metal translocation potential. Use of a non-food crop, poses no health risks in HssFCWs whereas the grains of are consumed directly by humans, presenting potential risks when used in HssFCWs. Compared to an annual , the perennial can be grown continuously in CWs for the phytoremediation of piggery effluent. Novelty statementNo known work about the phytoremediation potential of the two studied macrophytes in the agro-ecological zone is known. The study also provides insight into the bioconcentration of metals in the edible part of . FARO 44 (SIPI 692033).The characterization of piggery effluent revealed that its compositions were above the allowable limit for reuse and recycling despite the adoption of low-water use intensive method.The study showed that accumulates more metals in the above-ground tissues than in its root and provide insight into its use as a phytoremediation plant in the study area.The footprint of pollutants and metals in makes a perennial more suitable than in piggery effluent phytoremediation.