<p>The conversion of plant species into useful biomass is a key process in nowadays due to large amount of plant wastes are just dumped as a waste causing environmental pollution. The present investigation mainly focused on conversion of <i>Parthenium hysterophorus</i> a plant waste into biomass, which was used for the biosorption of copper from the textile industry effluent. The process conditions like contact time, dosage of biomass, concentration of metal ions, and pH are estimated using a batch process. A central composite design (CCD) under response surface methodology (RSM) software was applied to get the optimum process conditions. The percentage removal of copper was estimated as 98.1 using optimized process variables. The optimal conditions found were contact time—18&#xa0;min, dosage—0.5&#xa0;g, concentration—35&#xa0;mg/l, and pH—5. The batch mode experiments are also conducted and found the process conditions of contact time 30&#xa0;min, biosorbent dosage 0.7&#xa0;g, initial ion concentration 15&#xa0;mg/L, and pH 5. The kinetic, equilibrium, and thermodynamic data are calculated from experimental data. The kinetics data is well suited to second-order kinetics by considering correlation coefficient (<i>R</i>²) 0.993. The copper biosorption by <i>Parthenium hysterophorus</i> powder followed the Freundlich isotherm model based on the value of correlation coefficient. The characterization of biosorbent was performed to find the suitability of biosorbent for biosorption of copper. Thermodynamic parameters such as enthalpy change (∆<i>H</i>°), entropy change (∆<i>S</i>°), and Gibbs free energy (∆<i>G</i>°) change are also determined and found that biosorption is endothermic, spontaneous, and reversible. From the results, it was concluded that <i>Parthenium hysterophorus</i> biomass was the best for the removal of copper from the textile industry effluent.</p> Graphical Abstract <p></p>