Experimental and theoretical investigation of lead ion adsorption from the synthetic wastewater using the biosorbent derived from Cardita bicolor shell

Lead is one of heavy metal ions which pollute the environment as the result of discharge of wastewaters discharged by industrial activities. In the current study, the biosorbent derived from Cardita bicolor shell was used for the first time to adsorb lead ions from aqueous media. The biosorbent was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and Brunauer-Emmett-Teller (BET) analyses. BET results showed that the specific area of the prepared biosorbent was 68.25 m(2)/g. In addition, it was observed that the current biosorbent was mesoporous. The operating parameters, including solution pH, stirring rate, lead ion initial concentration, contact time, temperature, and biosorbent dosage, were optimized through batch adsorption experiments, and the maximum adsorption efficiency of 97.57% was yielded. The current biosorbent showed an acceptable efficiency in 5 adsorption/desorption cycles. Equilibrium and kinetic studies approved the performance of Freundlich (R-2 = 0.9947) and pseudo-second-order (R-2 > 0.999) models, respectively, and the achieved maximum adsorption capacity of the biosorbent was 18.416 mg/g. Additionally, based on thermodynamic investigations, the current adsorption process was exothermic (Delta H degrees = - 44.683 kJ/mol) and spontaneous (Delta G degrees < 0). Moreover, a group method of data handling (GMDH) artificial neural network (ANN) model was applied to predict the adsorption percentage of lead ions between 52.38 and 98.46% using the prepared biosorbent. The proposed model presented an acceptable performance in prediction of the outputs of the process (R-2 > 0.93). Considering the achieved results, it is possible to decrease the required time and cost of the process by using the GMDH artificial neural network model through the prediction of the uptake percentage of lead ions from aqueous systems.