Cryptomelane Modified Biomass Wastes for Solar Interfacial Evaporation and Stabilization of Cadmium

Abstract In recent years, solar interfacial evaporation has received increasing attention due to its potential applications in power generation, seawater desalination, and wastewater treatment. In this work, after carbonization of two biomass wastes, rice husk and coconut husk, they were modified by hydrothermally synthesized cryptomelane manganese and prepare into a solar interfacial evaporation system to explore their evaporation performance and stabilization performance of cadmium. The results demonstrate that the cryptomelane modified biochar can obtain an evaporation rate of 1.085 kg m− 2 h− 1 and a photothermal conversion efficiency of 77.75% under one sun (1 kW m− 2). Under the condition that the average solar power density is only 465.22W m− 2, the evaporation amount reaches 4.7kg m− 2 within six hours, and the evaporation rate reaches 0.78kg m− 2 h− 1. The two kinds of biomass wastes modified by cryptomelane have enhanced adsorption performance for cadmium, and can be well used for long-term stabilization and recycling of Cd. It could be verified that the cryptomelane modified biochar material is a low-cost, scalable and efficient material for interfacial evaporation and reduce wastewater pollution.