People Report
People Report 2013 2 bioplastics MAGAZINE Reinventing waste as a resource Bacteria and biopolymers key players in innovative hospital waste management system By: Karen Laird www.pharmafilter.nl Due to the specific nature of health care activities, waste management in hospital environments poses problems not encountered elsewhere. In most hospitals, therefore, elaborate procedures have been put in place to ensure that the health-care waste they produce is appropriately managed. However, even with the strictest of segregation, transport and disposal regulations in force, cross-contamination and errors occur. Pharmafilter is a young Dutch company offering a new and innovative approach that completely eliminates these problems. At the heart of its solution is an anaerobic digester; over time, biopolymers will become a major source of digestible input material. Health-care waste includes a large component of general waste and a smaller proportion of hazardous waste. According to Eduardo van den Berg, director of Pharmafilter, one of the main problems is where to draw the line between the two. “In hospitals, waste is managed by segregating it, which creates a great many separate waste streams. We found that fully one-third of all movement in hospitals is related to waste. A lot of effort, for example, goes into carefully separating all the infectious waste from the general waste.” He added: “But then, if a patient - the source of the infection – uses a bedpan or goes to the toilet, that is infectious waste that goes directly into the sewer.” Down the drain Van den Berg is a creative thinker with a proven track record and experience in health-care settings. An earlier idea – the development of a hygienic, environmentally friendly, disposable vase for hospital flowers – had been successfully introduced in hospitals throughout the Netherlands and Germany. He was convinced that there had to be a safer, cleaner and especially, a more efficient approach to the transport, handling and treatment of the health-care waste produced in hospitals. So when he was approached by Reinier de Graaf hospital, in Delft, the Netherlands, who asked him to help devise a modern, safe and efficient waste management system for the new facilities that were being planned, he came up with an solution that was both impressively simple and remarkably effective. “I thought, why not simply treat all the waste produced as biohazardous waste? Then, instead of separating everything for segregated disposal, all the waste streams could be combined into a single stream, disposed of in a single contaminated area and processed all together,” he explained. How? “Simply by using the hospital’s existing sewage system.” 30 bioplastics MAGAZINE [01/14] Vol. 9
Report Using the hospital’s internal drainage system would greatly decrease the amount of waste being transported through the hospital, thus considerably reducing the number of contact moments and contamination risks. In a purely practical sense, it would have the added advantage that far less use would be made of the elevators, reducing the waiting time for them, as well. First, however, a safe and workable system for implementation needed to be devised. “Obviously, because the municipality it not equipped to handle contaminated waste through the sewage system, some kind of self-contained treatment facility would be needed on site to process this waste. This was the start of Pharmafilter,” said Van den Berg. In 2008, the first Pharmafilter pilot plant was built, in order to test the feasibility of the idea and the configuration of the installation developed by Van den Berg. This pilot facility operated on a 10% scale at Reinier de Graaf Gasthuis in Delft and proved such a success that a full-scale system was installed in the existing H-building, which went on stream in the autumn of 2010. And today, construction of the new hospital facilities in Delft is in full swing, together with the integrated new Pharmafilter installation that will be ready for operation from day one. The new waste disposal system has also attracted attention from other hospitals as well, both in the Netherlands and abroad. Pharmafilter currently has 10 more projects for similar systems with hospitals in Belgium, Denmark, Germany, Holland, Ireland, Sweden and the United Kingdom. Powered by bacteria Standing in one of the containers housing the Pharmafilter installation, Van den Berg called attention to the fact that there was no odor – nothing at all – even though underneath the floor all the waste from the hospital was going through a giant sieve to separate the solids from the water. “On all the wards, where the bedpan washers used to be, and in the operating rooms and other strategic locations, we’ve installed shredders, called Tontos, into which all waste is deposited, including food, sharps, disposables, human organic waste, plastic, paper, whatever. The self-cleaning Tonto unit grinds up the waste, adds water and delivers it via the hospital’s internal sewer system to where we are standing, together with the waste water from showers, washbasins and toilets,” explains Van den Berg. “We purify the air of all aerosols and possible pathogens, so there’s no smell or danger of contamination at all.” After sieving, the solids – metals, plastics, feces, food - are ground into pulp, suctioned into the hydrolysis unit and then fed into the anaerobic digester. Here, the organic waste, including all bioplastics, is digested by the bacteria in this unit, a process that takes around thirty days and occurs at a temperature of 60°C. The biogas produced in the process meets 65-70% of the power needs of the installation. The non-digestible remainder is largely decontaminated during the process as well, but is nonetheless treated at 100°C prior to being compressed and further processed into briquettes that for instance can serve as fuel in the cement industry. Van den Berg hopes that, as the volumes increase, it will be possible to separate the metals and conventional non-digestable plastics out for recycling in order to achieve a true end-of-life cycle closed loop. No more pharmaceutical pollution The wastewater, which next to all else contains high amounts of pharmaceutical substances, from cardiovascular medicines to X-ray contrast fluids, undergoes rigorous purification treatment, as well. The water from the sewagesieving step and from the digester is first fed through a membrane bioreactor equipped with ultrafiltration membranes, where bacteria are responsible for nitrogen and phosphate removal and most of the contaminants are eliminated. Next, ozone is introduced into the water to get rid of any color, micro particles of cosmetics and pharmaceuticals remaining. The ozone causes chain scission into basic elements and metabolites. “After the ozone treatment, an bioplastics MAGAZINE [01/14] Vol. 9 31
