ABSTRACT
The meeting was long and intense. After all, more than $50 million had been invested in this waste treatment plant, and still, the objective of the treatment, namely, to produce recycling materials with a certain quality, could not be reached. Engineers, plant operators, waste management experts, financiers, and representatives from government were discussing means to improve the plant to reach the goals set. A chemical engineer took a piece of paper and asked about the content of mercury, cadmium, polybrominated diphenyl ethers (PBDEs), and some other hazardous substances in the incoming waste. The waste experts had no problem indicating a range of concentrations. The engineer then asked about the existing standards for the products, namely, cellulose fibers, plastic fraction, and compost. Again, he got the information needed. After a few calculations, he said, “If the plant is to produce a significant amount of recycling material at the desired specifications, it must be able to divert more than 80% of the hazardous substances from the waste received to the fraction that is incinerated. Does anybody know of a mechanical treatment process capable of such partitioning?” Since none of the experts present was aware of a technology to solve the problem at affordable costs, the financiers and government representatives started to question why such an expensive and state-of-the-art plant could not reach the objective. It was the old mayor of the local community, who experienced most problems with the plant because of citizens complaining about odors and product quality, who said, “It seems obvious: garbage in, garbage out; what else can you expect?”
