Speaking at the CIWM London and Southern Counties open meeting last Friday (September 19), Mary Corin, consultant and former director of recycling development at Viridor, warned that the value of recovered materials would not improve unless a quality assurance system was introduced all along the supply chain.
Ms Corin said that, in addition to greater public awareness over contamination, more training was needed for collection crews and employees at waste transfer stations and MRF operatives should not be the ones held solely responsible for contaminated material getting through the system.
She said: “We need a robust quality assurance system for every point that waste arises whether it is kerbside sorted or not, we need it all along the whole system.”
Quality
Questioning why some crews still picked up contaminated materials and waste transfer stations forwarded materials to MRFs that could not be reprocessed, Ms Corin urged tighter quality controls to be introduced throughout the chain.
Ms Corin drew attention to the Chinese Certification and Inspection Company, which provides thorough quality inspections on material being exported between the UK and China, as an example of how a quality assurance test should run.
Also advocating the role of quality in any collection scheme, Linda Crichton of WRAP was keen for councils to look at the end market and the potential to produce saleable material.
Ms Crichton, ROTATE manager at WRAP, said: “Quality underpins the sustainability of the whole recycling chain, it is the lynch pin which the whole economy depends on and quality means that we can sell in higher value markets.”
In a call for more training, Ms Corin pointed out that by teaching staff to spot and not collect contaminated material would be beneficial in the long run and insinuated that the problem was something faced by both source segregated and commingled collections.
She said: “There is still no guarantee that kerbside sorting will have anything to do with quality, it is to do with training, if I can see the half eaten curry that came in, then so can the crew.”
Bryson
Contrary to Ms Corin's claims, Eric Randall, of waste service provider Bryson Recycling, stated that kerbside collected boxes could lead to less contamination.
He claimed that contamination of recycled product collected source segregated was under 0.5% in the end product and under 10% in the material collected. He compared this to MRFs which, he claimed, had contamination rates of between 4 and 30% in its feedstock.
However, using evidence from a study carried out in the American state of Minnesota, Bruce Terrell, of joint venture company Community Waste, said neither system was assured of generating a more quality product than the other.
Mr Terrell said that, in the Minnesotan study, over 85% of end market users said blanket statements cannot be made about either commingled or source segregated collections as both were capable of “producing extremely good and extremely bad material”.
Technology
Ms Corin said that the waste industry could combat contamination in another way with the development of the sorting machinery being used in MRFs. She claimed that the introduction of robotic arms to pick material in MRFs should be investigated as an idea in a move towards fully automating facilities.
Using the example of assembly line machinery capable of painting cars, Ms Corin said that the introduction of such a system could reduce labour costs at MRFs and machinery currently being used to sort commingled recyclables was still at a developmental stage.
“The technology is still evolving, if anyone saw a paper mill 100 years ago the principle that they were using was essentially the same but it is now much more sophisticated,” she said.
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