Integrated systems for treatment of healthcare waste

What if you could build a facility that took in many types of medical waste and made it safe for disposal? How big would you build the process and what would you include in it?

If we consider the waste treatment needs for a geographic area, there are options for configuration. Let’s simplify these to (1) on-site treatment, (2) cluster treatment, and (3) central treatment.

On-site treatment is processing of the waste at or near the point of generation, often in the same building. This may be preferred when waste generation rates are low, are sporadic, or are so unstable or dangerous that transport to another treatment site is unfeasible.

Cluster treatment involves facilities that take in one type of waste but from several generators. The treatment process may be located where some of the waste is generated and accept waste from other facilities in the area. For instance, a complex of doctors offices may have a machine that stamps and crimps sharps to make them less hazardous before they are sent for further treatment or disposal. In addition to processing the sharps waste produced at the immediate doctors’ offices, the machine may process sharps waste from other medical facilities in the area.

Central treatment is the most ambitious and comprehensive. A central treatment site accepts waste from many generators within a say, 120-mile radius. It also accepts different types of waste and has multiple processes for treatment and preparation for disposal.

On-site Cluster Central
Small throughput, limited range of waste Larger throughput, limited range of waste Large throughput, can process many types of waste

Pluses and minuses

The downside of a central treatment facility is that waste must be transported long distances and that poses a risk. But today’s storage and transportation solutions are good enough that the trade-off is worth it.

The upsides of a central treatment facility are cost savings and more reliable treatment. Policing waste treatment at thousands of sites is impractical so regulators prefer centralized treatment. And many generators do not have the money or expertise for on-site treatment. It is not economic to treat small quantities. This is particularly true for incinerators. Decades ago every hospital had an incinerator. Big incinerators are more efficient and overall cheaper, especially when the cost of a pollution abatement system is included.

Efficiency of integrated facilities

Large, comprehensive waste-management facilities are effective. Policing of a few facilities is manageable, and large facilities can justify the wide variety of treatment systems needed to service the heterogeneous waste from a big geographic area. Also, permitting.

Also, different kinds of waste are sometimes able to treat each other. Acids and bases can neutralize each other. Acids can break emulsions. Waste oxidants can treat organics in water. Ash from an incinerator can help stabilize and solidify waste.

Elements of an Integrated Treatment Facility

Central Processing System

Unit operations must convert wastes to environmentally innocuous residuals. These residuals are air emissions, water discharge, and solids for landfill. Technologies:
  • Incineration = essential but expensive. Incinerator or pyrolyzer to destroy organic solids, liquids, and gases. Things not good for incinerators: containers, low-energy materials, corrosive stuff.
  • Biotreatment = this is how sewage is treated. Good for dilute aqueous solutions with organic materials.
  • Separation processes = for efficiency. Analogous to segregation in collection.
  • Stabilization of solids
  • Treatment of water-reactive material = must be stabilized before land disposal.

Unit operations you might find at a comprehensive facility

  • Water treatment: precipitation, ion exchange, filtration, dewatering, reverse osmosis, electrodialysis
  • Air treatment: acid scrubbing, particulate scrubbing, electrostatic precipitation, condensation, filtration
  • Chemical oxidation and reduction
  • Separations: evaporation, drying, freezing, liquid-liquid extraction
  • Physical size reduction - grinding, shredding, crushing Screening. Dewatering

Outbound - packaging for disposal