Design of a solar reactor based on porous nanocomposite ceramics for removal of heavy metal ions from wastewater

Abstract

Treatment of industrial wastewater containing heavy metal ions with inexpensive and effective methods is a basic need for the environment. The use of available materials such as soil, food or agricultural wastes that are abundant in the environment and renewable energy for industrial wastewater treatment is an important approach. In this research, a nanocomposite ceramic substrate (NCCS) was synthesized at 850 °C as a solar energy collecting bed and transferring fluid to the surface for evaporation. The NCCS was characterized using FT-IR, XRD, BET and, FE-SEM. The size of nano-hydroxyapatite in the NCCS and specific surface area were reported 25 nm and 15.93 m2g-1, respectively. The nano-hydroxyapatite increased NCCS hydrophilicity. Human hair created microchannels in the ceramic to transfer fluid to the surface. The surface temperature under the solar simulator and real sunlight radiation increased to 55 °C. Synthetic and real wastewaters were treated in this process and the removal efficiency of heavy metal ions was more than 75%. In this method, the turbidity of wastewater is reduced by more than 90%. In the laboratory and industrial-scale process, the average thermal conversion efficiency and evaporation rates were more than 70% and 1.74 kgm-2h-2, respectively. The physical and chemical performance of ceramic substrates was stable for up to 12 consecutive cycles and can then be regenerated.