Product system implications at end-of-life: An Economic and environmental assessment

While there are many opportunities to make adjustments in how products are produced and consumed to reduce environmental impact, this dissertation focuses on product reuse and proposes a framework to evaluate the economic and environmental effects of proposed interventions in the product system that encourage end-of-life product to be guided toward environmentally preferred reuse or recycling paths. A novel aspect of the approach requires characterizing the product system structure to distinguish between those interventions that maintain the interaction dynamics amongst product system actors (producers, consumers and government), and those that alter the product system structure, enabling unintended consequences. The consumer printing sector serves as the backdrop to demonstrate our framework over three essays. This sector was chosen because inkjet cartridges have a variety of end-of-life paths available in the United States, but the majority is still routed to the municipal waste stream after a single use. The first essay utilizes Life Cycle Assessment to quantify the environmental impact of an inkjet cartridge compared to remanufactured and multiple refilling alternatives. Results confirm that inkjet cartridge reuse provides environmental improvement over new inkjet cartridges. However, inclusion of how consumers go about purchasing and disposing of inkjet cartridges in the functional unit revealed changes in consumer behavior can have more bearing on environmental impact than what product alternative was purchased. The second essay uses economic modeling to show that it is possible to raise social welfare and maintain the original manufacturer\u27s profit by strengthening the firm\u27s intellectual property rights in exchange for the firm implementing greener physical product attributes. The third essay considers the economic and environmental effects of a product take-back regulation that may encourage recycling in a collective implementation or remanufacturing of the durable printer in an individual producer implementation. While take-back only applies to the printer market, we investigate the spillover effects to the cartridge market that resides within our product system model. While a collective take-back scheme minimizes environmental harm, welfare is also minimized. Whereas, under an individual take-back scheme, environmentally preferred remanufacturing of returned durable products may lead to a reduction in environmental harm while increasing welfare

Towards Increased Recovery of Critical Raw Materials from WEEE– evaluation of CRMs at a component level and pre-processing methods for interface optimisation with recovery processes

Increasing recovery of critical raw materials (CRMs) from waste electrical and electronic equipment (WEEE) is a strategic priority to mitigate supply risks. Today, CRM recovery rates are generally low, with increases requiring new recovery processes and interface optimisation with pre-processing to ensure appropriate material flows for efficient recovery are generated. Here, results from an industrial trial to increase CRM recovery from WEEE are presented to inform development of pre-processing strategies which generate such material flows. Au, Ag, Co, Ga, Mg, Nb, Ru, Pd, Ir, Y, Nd, Sb, Ta and W are identified with XRF in components of a range of WEEE samples including within individual printed circuit board (PCB) components. CRM distribution in PCBs is mapped by visual inspection with reference to this data. Cost-effective methods to disassemble WEEE; isolate CRM bearing components, and upgrade/concentrate CRMs are evaluated for industrial adoption. A guillotine is found most suitable for LCD disassembly and separation of Au edge-contacts from PCBs, while cryocracking is best for isolation of internal components of digital media devices. Thermal PCB disassembly with a solder bath for simultaneous SMD removal and subsequent sieving to sort SMDs thereby concentrating CRMs for recovery is a promising approach. Microwave ashing of PCBs to concentrate CRMs is promising although off-gas treatment would be required. Recovery potential of identified CRMs from material streams generated is found to be poor due to lack of suitable recovery infrastructure except for precious and platinum group metals in PCBs, but available pyrometallurgical recovery permanently dissipates other CRMs present

Nasopharyngeal colonization with nontypeable Haemophilus influenzae and recurrent otitis media

University of Chicago Press, Harabuchi, Y. ; Faden, H. ; Yamanaka, N. ; Duffy, L. ; Wolf, J. ; Krystofik, D. ; Williamsville, T.,Journal of Infectious Diseases, 170(4), 1994, 862-866. publisherThe relationship between nasopharyngeal colonization with nontypeable H. influenzae and recurrent otitis media was assessed in 157 children followed prospectively from birth through 12 months of age. Forty-nine (31%) became colonized. Nasopharyngeal secretory IgA (sIgA) reactive with the P6 outer membrane protein was detected in all colonized children. Reduction or elimination of the organism was associated with a better mucosal immune response (560 +/- 864 units/ng/mL of sIgA) than was persistence in the nasopharynx (121 +/- 81; P = .04). Forty colonized children (82%) and 61 noncolonized children (56%) developed otitis media (P = .004); colonized children were four times more likely to be classified as otitis prone (P = .003). The frequency of otitis media episodes was directly related to the frequency of colonization (r = .42, P < .01). These results demonstrate a strong relationship between nasopharyngeal colonization patterns and otitis media. The mucosal immune response may be important in elimination of potential pathogens from the respiratory tract