Exploring the adsorptive potential of chemically activated Nanoporous carbons derived from invasive goat weed for treatment of hospital wastewater

[Display omitted] •Novel sustainable chemically activated carbons samples were prepared from invasive Goat weed (Ageratum conyzoides).•ZnCl2 activated carbon are essentially micro porous, whereas H3PO4 activated carbon have both micro and meso porosity.•ZnCl2 activated carbon have higher surface area and removal efficiency than H3PO4 activated carbon.•ZnCl2 and H3PO4 activated carbon removes 90–93% and 85–88% of pollutants from hospital wastewater, respectively. Nanoporous activated carbons synthesized from goat-weed (Ageratum Conyzoides) using single-step pyrolytic chemical-activation with ZnCl2 and H3PO4 at various ratios. Nano-textural properties of samples assessed through N2 adsorption/desorption, XRD, SEM, and FTIR. ZnCl2 activation led to a high microporosity and maximum surface-area of 1699 m2·g−1 and total pore-volume of 1.23 cm3·g−1 (Zn/biomass ratio 1:1), while H3PO4 activation yielded 866 m2·g−1 and 1.24 cm3·g−1, respectively (P/biomass ratio 1.5:1). The adsorption capacity of samples follows surface-area variations of samples. During treatment of hospital wastewater, ZnCl2-activated carbon removed 90–93 % of pollutants, comparable to commercial carbon, while H3PO4-activated carbon removed 85–88 %. The adsorption mechanism of carbons during interaction with HWW contaminants was discussed to explain variation in removal efficiency.