The mean effluent metals (Cr, Cd, Ni, Cu, Zn, Pb, Fe, and Mn) concentration produced in different chambers of the septic tank, along with concentration profiles of the floating wetland within the four operational phases. Bars indicate standard errors. The symbols A1, A2, A3, A4, A5, and A6 represent wastewater collection points from settling chamber 1, settling chamber 2, the first compartment of the ABR, the second compartment of the ABR, filtration chamber, and floating wetland, respectively.