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

Abstract

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 (Na 2 CO 3 ) 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 Na 2 SO 3 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.

Effect of hydrothermal treatment temperature on the properties of sewage sludge derived solid fuel

“…In addition, the biosorbant properties of sludge (Smith et al 2009;Sassi et al 2010) was likely enhanced by the application of HT. The similar phenomena was reported by Jin et al (2010) that implement the heavy metals removal from wastewater and heavy metal stabilization in fly ash by a single hydrothermal treatment process with the addition of sodium carbonate.…”

Seed-Assisted Hydrothermal Treatment with Composite Silicon–Aluminum Additive for Solidification of Heavy Metals in Municipal Solid Waste Incineration Fly Ash

“…The leaching concentrations of Pb in HT product of CD-30-3-200 had been decreased to the lowest level (0.25 mg/L). As the element composition on the surface of tobermorine crystalline characterized by EDX is shown in Figure d, the enrichment of Pb (2.9%) Zn (5.8%), Cu (1.7%), and Cr(0.9%) on the surface was obvious because of the adsorption of heavy metals in holes or hollows on the surface of tobermorite crystalline, mainly as the result of chemisorption or physical encapsulation . The addition of a 30% mass of composite additive (including CFA and diatomite) and a 3% mass of tobermorite seed at a higher reaction temperature of 200 °C might be worthy of recommendation.…”

Co-Detoxification of Transformer Oil-Contained PCBs and Heavy Metals in Medical Waste Incinerator Fly Ash under Sub- and Supercritical Water

“…On the other hand, the XRD patterns in SI Figure S1 provided the evidence of new crystals, such as calcium sulfate (CaSO 4 ) and ferric oxide (Fe 2 O 3 ), formed in residues and sodium chloride (NaCl) previously detected in raw ashes are absent after supercritical water reaction. The toxic metals may be either absorbed or physically encapsulated in the stable mineral phases, and hence their mobility can also be prevented by more stable speciation from transferring toward environment . In addition, it is expected that full destruction of PAHs in both raw MWI fly ashes (SI Table S1) was achieved during supercritical water treatment by GC/MS analysis.…”

“…The toxic metals may be either absorbed or physically encapsulated in the stable mineral phases, and hence their mobility can also be prevented by more stable speciation from transferring toward environment. 34 In addition, it is expected that full destruction of PAHs in both raw MWI fly ashes (SI Table S1) was achieved during supercritical water treatment by GC/MS analysis. After reaction, three new peaks in residues (induced from MFA1) appeared: the peaks centered at 28.48°, 47.43°, and 56.26°can be attributed to cuprous chloride (CuCl) according to the PDF reference files (PDF 01-0793).…”