Biocarbon derived from Lantana camara L. leaf and seed for adsorption of heavy metals from floriculture wastewater

The rapid expansion of the floriculture industry has led to severe environmental challenges, particularly the discharge of heavy metal-contaminated wastewater. This study investigates the potential of biocarbon derived from Lantana camara leaves and seeds for the removal of toxic heavy metals including cadmium (Cd), lead (Pb), and zinc (Zn) from floriculture wastewater in the Lake Ziway, Ethiopia. The physicochemical parameters, including pH, electrical conductivity (EC), total dissolved solids (TDS), and suspended solids (SS), were measured, revealing significant contamination in the wastewater. Heavy metal concentrations of cadmium (Cd), lead (Pb), and zinc (Zn) were analyzed using atomic absorption spectroscopy. Biocarbon derived from the leaves and seeds of L. camara was evaluated for its potential to adsorb these metals. The biosorption efficiency of L. camara derived biocarbon was optimized, with leaf-derived biocarbon achieving 89.62% Cd, 83.0% Pb, and 78.0% Zn removal at an optimal dose of 4 g, compared to 77.14% Cd, 68.0% Pb, and 63.2% Zn for seed-derived biocarbon. Adsorption kinetics followed the pseudo-second-order model, and equilibrium adsorption was best described by the Langmuir isotherm. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the involvement of functional groups such as hydroxyl (-OH) and carboxyl (− COOH) in metal adsorption, while Brunauer–Emmett–Teller (BET) surface area analysis indicated that leaf-derived biocarbon had a higher adsorption capacity (230 cm2/g) than seed-derived biocarbon (180 cm2/g). These findings demonstrate the effectiveness of L. camara-derived biocarbon as a sustainable and cost-effective alternative for heavy metal removal from industrial wastewater. Further research is required to assess its long-term application in large-scale water treatment.