ABSTRACT
The meeting was long and intense. After all, more than $50 million had been invested in this mechanical waste-treatment plant, and still the objective of the treatment, namely to produce recycled materials of a given 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 its goals. A chemical engineer took a piece of paper and asked about the content of mercury, cadmium, 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 compost and cellulose fibers. 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 residue for landfilling. 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 mayor of the local community, who experienced most problems with the plant because of citizens complaints about odors and compost quality, who said, “It seems obvious: garbage in, garbage out. What else can you expect?”
