Co-disposal of Heavy Metals Containing Waste Water and Medical Waste Incinerator Fly Ash by Hydrothermal Process with Addition of Sodium Carbonate: A Case Study on Cu(II) Removal

Fly ash generated from medical waste incinerator and wastewater produced from electroplating plants contains various hazardous contaminants such as heavy metals and chlorinated organic compounds. The primary goal of this research was to investigate the feasibility of removing heavy metals from wastewater using medical waste incinerator fly ash as the treatment reagent with addition of small amount of sodium carbonate (Na2CO3) in a hydrothermal process. Copper (Cu) was used as the model heavy metal contaminant in the process. The results revealed that medical waste incinerator fly ash could effectively stabilize Cu(II) ion from wastewater, the crystal phase and simple substance formed during the treatment played a significant role in the fixation of heavy metals in wastewater and fly ash. The heavy metal leachability of treated ash was also measured after removal process. The co-disposal of Cu-containing wastewater and heavy metals-bearing medical waste incinerator fly ash by hydrothermal treatment with addition of a small amount of Na2SO3 was found promising as an effective way of removing Cu from wastewater. The reutilization feasibility of fly ash and the formation mechanism of copper-containing substances were also discussed in this paper.