Robots drive resource efficiency in clinical waste
A robot-operated disinfection process is diverting clinical waste from landfill, improving resource efficiency. Nick Warburton reports
At first sight, SRCL's disinfection process resembles a state-of-the-art car-assembly line. But the new technology, launched in the UK in late November, has the potential to transform the clinical waste sector, driving waste from landfill through the increased reuse of the containers used to collect sharps.
Clinical waste (hazardous healthcare waste) covers any material that is hazardous or might cause infection and by law requires specialist treatment.
While most clinical waste is still produced by the NHS and the private health care sector, councils have seen a marked increase in healthcare waste by domestic waste producers as the NHS has looked at greater levels of community care (LAWR February2012, page 8).
Local authorities, which already have a legal responsibility to collect healthcare waste from households, need to be aware of the correct process for managing clinical waste, especially sharps, which can pose a serious health hazard to waste handlers. It is this clinical waste stream that SRCL's new disinfection process targets.
Based in Leeds, the American-owned company runs a sharps management service that includes a managed service for clinical waste producers.
As part of the service, trained technicians deliver, locate, collect and exchange sharps bins from producer premises, reducing the risk of staff needle-stick injuries.
These waste containers are then taken to SRCL's Knostrop treatment facility where they are opened, emptied and disinfected using the company's new automated wash-line and robotics technology.
Paul Simpson, the general manager at Knostrop, oversees the entire process. He says: "Every container that we receive is bar coded, which ensures we meet our obligations. We can therefore demonstrate every step of the way where waste is at a given time."
Until the new process went live, the containers, depending on the contents of the sharps in the bins, would previously have been sent for incineration or alternative treatment.
However, as Simpson explains, due to legislation and the difficulties in segregating, most of the bins are deemed to contain a pharmaceutical material of some description and therefore are incinerated. The bottom ash from the incineration is used as a top cover on landfills.
In the case of orange-lidded containers, which denote that waste is suitable for treatment, the common procedure is to shred the bins and the sharps contents and pass the waste through a disinfection unit. The residue material is then sent to landfill. However, this is only a fraction of the overall waste generated.
"The percentage that is passing through alternative treatment facilities is very low because of the segregation difficulties experienced," he says.
Based on SRCL's experience in the US, Simpson estimates that the new treatment process will enable the company to reuse the sharps containers up to 600 times.
This obviously has huge implications for resource efficiency, not only in terms of diverting large volumes of containers away from ultimate landfill disposal, but also dramatically cutting down on the carbon footprint associated with the corresponding packaging of single-use containers.
So how does the new treatment process work and why is it so effective? Simpson explains the process, which starts when the containers' bar codes are scanned on arrival and are then loaded onto a two-part conveyor system.
Next, the twin robot system comes into operation. The first robot detects the container size by measuring its height and width, and then removes the lid, placing it on one of five designated washer lanes.
The second robot lifts the container and decants the sharps into a large 770-litre container. It then dips the container in a cold water pressure wash to remove any solids before loading it on the conveyor in the correct lane.
The container and lids then pass through a three-stage disinfection process that raises the temperature through each stage of washing, sanitising and finally drying. Once completed, the containers are reassembled, placed onto the carts and covered ready for re-issue to customers.
Before the system began operating, Dr Malcolm Holliday, of the Microbiology Department, Freeman Hospital in Newcastle upon Tyne, validated the machine.
The tests carried out by Dr Holliday verified that the system met the required disinfection standards by measuring the removal of bacteria and blood samples painted on containers before processing them through the automated wash-line.
As Simpson explains, SRCL tests the machine each day to ensure that it meets these same operating standards.
"At the start of every working day, we will run a container through the system with temperature data loggers to ensure that the operating parameters are at least in line with those with which we validated the machine at," he says.
"We also take a percentage of containers, which are swabbed and tested. It's important that people know that we are not just assuming that the machine has done its job."
With resource efficiency high on the political agenda, novel technologies such as this could usher in a brave new world in waste handling.
Nick Warburton is editor of LAWR