Table 2.
HCRW treatment technologies [64].
| Treatment Methods | Description | Types of Waste Treated | Temperature for Treatment | Treatment Time | Advantages | Disadvantages |
|---|---|---|---|---|---|---|
| Incineration | High-heat treatment converts waste into ash and exhaust gases. | Anatomical, infectious, and pharmaceutical wastes | Primary chamber 800–900 °C Secondary chamber 900–1200 °C |
4–6 h per batch | Suitable for treatment of all types of hazardous HCRW. Reduces the volume significantly. |
Produces air pollutants, carcinogens (dioxins, polychlorinated biphenyls, polycyclic aromatic compounds) and harmful gases (HCl, HF, SO2). Very costly. |
| Autoclave | Use saturated steam to disinfect infectious waste. | Infectious, pharmaceutical, and sharps | 121–140 °C | 30–60 min per batch | Has better public acceptance than incinerators. | The disinfected waste is landfilled. The discharged moisture contaminates the environment. |
| Microwave | Steam-based technology. Uses microwave disinfection to treat waste. | Infectious, pharmaceutical, and sharps | 95–100 °C | ≥30 min per batch | Has better public acceptance than incinerators. | The disinfected waste is landfilled. |
| Reverse polymerization | Uses microwave energy to treat waste. Shredding is applied to the final sterilized carbon residue. |
Infectious waste | 180–370 °C | 50–80 min per batch | Decreases the quantities of waste. | Use of Sodium Hydroxide (NaOH) and a scrubber to control gaseous emissions. Production of wastewater. Extremely costly. |
| Chemical disinfection | Uses a chemical technology with sodium hypochlorite as a disinfectant. | Liquid waste | 95–155 °C | 25 min exposure per batch | Low air emissions. Simple and convenient, good deodorization effect. |
Production of liquid waste containing sodium hypochlorite (NaOCl). |
| Pyrolysis | Heats waste organic components under oxygen-free or -depleted conditions, breaks chemical bonds to transform combustible liquid and gas. | Infectious waste | 540–830 °C | 45 min | Pyrolysis technology has a high energy recovery rate, minimal secondary pollution, and sufficient economics. | Commonly used for organic materials. It occurs at high temperatures. |
| Gasification | Gas cloud formed by the ionization of an inert gas, usually referred to as the fourth state of matter. | Infectious waste | 3000 °C | 1/1000 s | Treats all HCRW. | Expensive. Energy demanding. |