Ecofriendly synthesis of hydrated manganese oxide and its efficient adsorption of lead ions from water

Utilizing the waste liquid derived from graphene oxide synthesis as raw material, hydrated manganese oxide (HMO) was prepared by a chemical precipitation method with sodium hydroxide solution or aqueous ammonia solution. The HMO samples were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Zeta potential analyzer, and scanning electron microscopy. The adsorption characteristics of the HMO samples were examined through lead ion adsorption from water. The effects of adsorption temperature, starting lead ion concentration, and adsorption time on the lead ion adsorption capacity were investigated. The relevant data agreed well with the pseudo-second-order kinetic model and the Langmuir isotherm model. Additionally, the maximum adsorption capacities of HMO-1 are 70.897 mg g(-1), 76.660 mg g(-1), and 79.424 mg g(-1) for the lead ions at 298 K, 308 K, and 318 K, respectively. The lead ion adsorption mechanism of HMO has been explained. The findings indicate the as-synthesized HMO can be used as an efficient adsorbent material for eliminating lead ions from water.

Automated summary

In this study, hydrated manganese oxide (HMO) was prepared from waste liquid derived from graphene oxide synthesis using chemical precipitation method. The adsorption characteristics of HMO in removing lead ions from water were investigated. The experimental data fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacities of HMO-1 were found to be 70.897 mg g(-1), 76.660 mg g(-1), and 79.424 mg g(-1) at 298 K, 308 K, and 318 K, respectively. The findings suggest that HMO can be used as an efficient adsorbent material for lead ion removal from water.