Study on the adsorption performance and mechanism of pb (II) in water by biochar prepared from coconut shell

The direct discharge of lead containing wastewater into the environment without treatment poses a serious threat to the ecosystem and human health. Therefore, efficient, environmentally friendly, and low-carbon treatment of lead-containing wastewater is one of the critical issues that need to be addressed urgently. In this study, three types of biochar (designated as B450, B550, and B650) were independently prepared from agricultural and forestry waste coconut shells, and the effects of factors such as adsorption time, initial solution concentration, solution pH, and biochar dosage on the adsorption of Pb(II) in water by biochar were investigated through static adsorption experiments. The experiments showed that at a temperature of 30 °C, an initial solution concentration of 100 mg/L, a dosage of 8 g/L, a pH of 5, and an adsorption time of 3 h, biochar B650 exhibited the best adsorption effect on Pb(II) in water. The isothermal adsorption curves of the three types of biochar on Pb(II) in water could be well fitted with both Freundlich and Langmuir equations, and B650 showed the strongest adsorption capacity for Pb(II) in water.