Construction and Demolition (C&D) wastes are materials produced in the process of construction, renovation, or demolition of structures (buildings and roads). It also includes materials generated as a result of natural disasters (EPA, 2009). Preliminary estimates from the U.S. Environmental Protection Agency (EPA) show that the nation generated more than 160 million tons of building related C&D wastes in 2003. Also, Pennsylvania Department of Environmental Protection (PADEP) estimated that in 2005, Pennsylvania disposed over 2.25 million tons of C&D wastes in its municipal and C&D landfills (PADEP, 2009).Though previous studies have shown that it is cost-effective and environmentally friendly for contractors or construction managers to recycle C&D wastes rather than disposing them in landfills, these previous studies, however, paid little or no attention to detailed cost of recycling C&D wastes in a particular geographical area or region as compared to the availability of market for recycled materials or monetary value of the recycled materials. Hence, the objective of this study was to develop a mathematical model that helps stakeholders in construction business to evaluate the potential cost of recycling C&D waste components in their geographical area or region, and the potential revenue from the recycled materials. The model developed in this thesis will enable private companies or individuals to identify, invest and participate in the recycling of C&D waste components that yield good profits in their region or area. It will also enable Government to identify, sponsor or provide incentives for the recycling of C&D waste components that yield no or less profit in order to reduce environmental pollution and generate jobs. A case study is conducted in Pennsylvania to test the model developed in this thesis and the test has been successful. Based on the mathematical model and logic structure for selecting C&D waste components for recycling, drywall, roofing shingles and wood are identified as the components whose recycling will yield good profit and thus may not need government's support or incentives. Moreover, C&D waste components such as concrete, brick, block and asphalt, have been identified as components whose recycling will not be profitable enough and therefore would require government's support or incentives. The result of the case study also shows that the quantity of non-ferrous metals in C&D wastes are very small and their recycling will not yield any significant profit. / Civil Engineering

The last few decades have seen an explosion in population growth and along with this growth we have also witnessed an increase in demand for products. Although our resources are limited, consumers' needs know no bounds. It is not surprising that we are also increasingly demanding more from our environment. It is therefore imperative that we make better use of our resources and reassess how we construe a product's lifecycle. Instead of a linear perspective, which typically follows a product's lifecycle from mining of raw materials to manufacturing, but then stops when products are trashed, we need to use a circular perspective, where we focus on the entire lifecycle of products, from not just manufacturing to usage, but also from usage to creation of new products through recycling. The focus of this dissertation is on understanding two important processes in the circular economy: that of usage and disposal. I focus on the role that consumers' product valuations play in these processes. In essay 1, I show that consumers value products made from recycled materials more than comparable regular products. I also document why this happens and demonstrate how this affects usage. In essay 2, I investigate the relationship between reuse and product disposal. The circular economy is based on what is now referred to as the 3R approach: reduce, reuse, and recycle. However, I show that consumers are more (vs. less) likely to trash products that they have used extensively (vs. rarely). This then leads to a conundrum: if we encourage consumers to reuse products extensively, it appears that they are more likely to trash them. It is therefore imperative that we understand this relationship better and find interventions to mitigate this negative relationship. / Doctor of Philosophy / The last few decades have seen an explosion in population growth and along with this growth we have also witnessed an increase in demand for products. To create a more sustainable world, it is imperative that we move towards a more circular economy, where we not only minimize waste, but also find ways to extract more use from our resources. One way to do this is to find ways to reuse products after they have reached the end of their lifecycle. The focus of this dissertation is on understanding two important processes in the circular economy: that of usage and disposal (essentially addressing questions about what to do with products that we no longer have a need for). I primarily focus on the role that consumers' product valuations play in influencing these processes. In essay 1, I study how consumers feel about products made from recycled materials. I find that consumers are willing to pay more for products made from recycled materials compared with products made from regular raw materials. The higher willingness to pay emerges because consumers value the process that transforms the recycled materials into brand new products. I also show that this valuation impacts use: consumers use products made from recycled materials more judiciously. In essay 2, I investigate the relationship between product usage and disposal. I find that when consumers use a product more extensively, they are more likely to trash the product compared with other forms of reuse, such as, disposing in the recycling bin, giving it to others, or reselling it. This effect emerges because when consumers use a product more frequently, they believe that the product has less value remaining for others, and a product that confers lower value to others should be trashed.

According to the International Energy Agency, the global Electric Vehicle (EV) sales are experiencing approximately 24% annual growth and the total market could reach 4 million in 2020 and 21.5 million by 2030. However, the mass production of lithium-ion batteries (LIBs) to power EV creates concerns over environmental impacts and the long-term sustainability of critical elements for producing the major battery components. Although much investment has been made, it is still imperative to develop an effective LIB production and recycling process. This dissertation demonstrates a green and sustainable paradigm for LIBs where the batteries are manufactured and direct recycled to form a closed loop. The water-based cathode electrode delivers comparable cycle life and rate performance to the ones from the conventional organic solvent-based process. The direct recycling process has the advantages to regenerate the cathode material from electrode instead of decomposing into elements. Utilization of a water-soluble binder enables separating the cathode compound from spent electrodes using water, which is then successfully regenerated to deliver comparable electrochemical performance to the pristine one. When scaled up, the degraded cathode material can be directly regenerated by an optimized relithiation thermal synthesis (RTS) method to resynthesize the homogeneous cathode powder of high quality. The key factors and sintering procedures are studied to ensure the performance of the product. The pilot scale test successfully scales up to Kg-level with recycled output materials delivering good electrochemical performance. To automate the direct recycling process and improve the efficiency, machine learning and sensors are utilized in a novel battery disassembly platform. It can classify different batteries based on their types and sizes. The processing temperature is instantly monitored using thermal imager, and the prediction model is trained to give the prediction for measures taken by a closed loop control system. Furthermore, the image recognition is employed for quality control after the cutting process and the defect can be mitigated to ensure effective dismantling of End-of-life (EOL) batteries. The integration of machine learning techniques makes the elaborate dismantling process safer and more efficient. / Doctor of Philosophy / According to the International Energy Agency, the global Electric Vehicle (EV) sales are experiencing approximately 24% annual growth and the total market could reach 4 million in 2020 and 21.5 million by 2030. However, the mass production of lithium-ion batteries (LIBs) to power EV creates concerns over environmental impacts and the long-term sustainability of critical elements for producing the major battery components. In this work, a green and sustainable manufacturing and recycling paradigm for LIBs is ushered and scaled up to pilot-scale test. Compared with the electrodes produced by conventional organic solvent-based process, the water-based electrodes can deliver comparable battery performance, meanwhile reduce the cost as well as the pollution to environment. The spent batteries are successfully regenerated to form the closed loop system with minimal external toxic solvent used. At pilot-scale, Kg-level battery material can be directly regenerated to deliver high-quality cathode powder. It provides the guidance of design parameters for large-scale battery recycling in industry. To automate the direct recycling process and improve the efficiency, machine learning and sensors are utilized in a novel battery disassembly platform. The integration of machine learning techniques makes the elaborate dismantling process safer and more efficient.

The methods of applied behavioral science were used in developing and evaluating a program of resource recovery in a number of local Presbyterian churches. Household aluminum scrap was collected and sold to a local recycling center, and the proceeds were contributed to the established 'Halt Hunger' program of the Presbyterian, U.S., denomination. Behavioral interventions were prompts, proximity of collection container, and feedback; the dependent variable was pounds of aluminum recycled. Results indicated that smaller churches which used frequent prompts tended to have larger collections of aluminum; the location of the collection container did not significantly influence the size of the aluminum collections. Contributing the proceeds from the recycled aluminum to an established church program was reported by participants to be an important incentive for collecting aluminum scrap. Because volunteers collected and transported the scrap aluminum, the program was markedly cost effective. / M.S.

M.S.

The production of second generation biofuels -- cellulosic ethanol from renewable lignocellulosic biomass has the potential to lead the bioindustrial revolution necessary to the transition from a fossil fuel-based economy to a sustainable carbohydrate economy. Effective release of fermentable sugars through biomass pretreatment followed by enzymatic hydrolysis is among the most costly steps for emerging cellulosic ethanol biorefineries. In this project, two pretreatment methods (dilute acid, DA, and cellulose solvent- and organic solvent-lignocellulose fractionation, COSLIF) for corn stover were compared. It was found that glucan digestibility of the corn stover pretreated by COSLIF was much higher, along with faster hydrolysis rate, than that by DA- pretreated. This difference was more significant at a low enzyme loading. Quantitative measurements of total substrate accessibility to cellulase (TSAC), cellulose accessibility to cellulase (CAC), and non-cellulose accessibility to cellulase (NCAC) based on adsorption of a non-hydrolytic recombinant protein TGC were established to find out the cause. The COSLIF-pretreated corn stover had a CAC nearly twice that of the DA-pretreated biomass. Further supported by qualitative scanning electron microscopy images, these results suggested that COSLIF treatment disrupted microfibrillar structures within biomass while DA treatment mainly removed hemicelluloses, resulting in a much less substrate accessibility of the latter than of the former. It also concluded that enhancing substrate accessibility was the key to an efficient bioconversion of lignocellulose. A simple method for determining the adsorbed cellulase on cellulosic materials or pretreated lignocellulose was established for better understanding of cellulase adsorption and desorption. This method involved hydrolysis of adsorbed cellulase in the presence of 10 M of NaOH at 121oC for 20 min, followed by the ninhydrin assay for the amino acids released from the hydrolyzed cellulase. The major lignocellulosic components (i.e. cellulose, hemicellulose, and lignin) did not interfere with the ninhydrin assay. A number of cellulase desorption methods were investigated, including pH adjustment, detergents, high salt solution, and polyhydric alcohols. The pH adjustment to 13.0 and the elution by 72% ethylene glycol at a neutral pH were among the most efficient approaches for desorbing the adsorbed cellulase. For the recycling of active cellulase, a modest pH adjustment to 10.0 may be a low-cost method to desorb active cellulase. More than 90% of cellulase for hydrolysis of the pretreated corn stover could be recycled by washing at pH 10.0. This study provided an in-depth understanding of biomass saccharification for the production of cellulosic ethanol for cellulose hydrolysis and cellulase adsorption and desorption. It will be of great importance for developing better lignocellulose pretreatment technologies and improving cellulose hydrolysis by engineered cellulases. / Master of Science

This dissertation examines the relationship among practices and policies of waste/ing and economic structures to make visible the implications of vehicle disposal policies for environmental policy and theory. Consequently, I attempt to build upon the small body of literature that is now critically engaging with waste production and resulting actions/inaction in the form of policies of management. In doing this I use waste as a lens to examine the interrelationships among environmental degradation and economic and political structures. Further, I examine these phenomena in relation to a physical object, the automobile, to add materiality to abstract notions of waste as it relates to both the political and the economic. Through vehicle recycling policies, I analyze how underlying economic structures in contemporary capitalism result in specific responses to the "problems" of waste as well as how the related responses, or "solutions" perpetuate an un-ecological industrial system which severely restricts the possibilities of making substantial change in the production of environmental harms. / Ph. D.

Deep-pit caged layer waste which had accumulated for about 2-yr was collected from beneath hens housed on wire mesh cages, was mixed with chopped corn forage and ensiled in 2 kg cardboard containers double lined with polyethylene bags and sealed to study fermentation characteristics and microbial analyses. Proportions of corn forage and caged layer waste, wet basis, were 100:0, 80:20, 70:30, 60:40, 50:50 and 40:60. Corn forage and caged layer waste in ratios of 100:0, 70:30, 60:40 and 50:50 mixtures, were ensiled in 210 liter metal drums doubled lined with polyethylene bags, to study fermentation characteristics, microbial analyses, chemical composition and to conduct a metabolism trial. For both types of silos the pH of the ensiled mixtures increased (P<.01) as level of waste increased. Lactic acid was higher (P<.01) for waste containing silages, compared to corn silage. Total coliforms, fecal coliforms, salmonella, shigella and proteus were decreased or eliminated by ensiling. Dry matter, crude protein, and ash increased (P<.01) with waste levels. In a sheep metabolism trial, 30 wethers were fed diets consisting of the five silages in large silos, also, corn silage with sufficient soybean meal added to increase the crude protein content to that of 70:30 silage was used as a fifth diet. Digestibility of dry matter and organic matter was higher (P<.01) for the corn silage diet, compared to the corn forage-waste silage diets, but the differences were small for organic matter. Within corn forage-waste silages a linear decrease (P<.05) was recorded in dry matter digestibility as caged layer waste increased. Apparent digestibility of dry matter, crude protein, organic matter, neutral detergent fiber (NDF), and acid detergent fiber (ADF) was higher (P<.01) for corn silage supplemented with soybean meal, compared with 70:30 corn forage-waste silage diet. Higher (P<.01) N utilization was obtained for sheep fed the corn silage diet, compared with those fed the waste treated silages. No difference (P<.05) in N retention was recorded when sheep were fed 70:30 corn forage-waste silage diet or corn silage supplemented with soybean meal. / Master of Science

The demand for Lithium-ion batteries (LIBs) has been growing exponentially in recent years due to the proliferation of electric vehicles (EV). A large amount of lithium-ion batteries are expected to reach their end-of-life (EOL) within five to seven years. The improper disposal of EOL lithium-ion batteries generates enormous amounts of flammable and explosive hazardous waste. Therefore, cost-effectively recycling LIBs becomes urgent needs. Lithium nickel cobalt manganese oxides (NCM) are one of the most essential cathode materials for EV applications due to their long cycle life, high capacity, and low cost. In 2008, 18.9% of Lithium-ion batteries used NCM cathode material worldwide while this number increased to 31% six years later. An environment–friendly and low-cost direct recycling process for NCM has been developed in this project. The goal of this project is to recycle the EOL NCM and yield battery-grade NCM with equivalent electrochemical performance compared to virgin materials. In order to achieve this goal, four different heat treatment conditions are investigated during the direct recycling process. From the experimental results, the charge and discharge capacities of the recycled material are stable (between 151-155 mAh/g) which is similar to that of the commercial MTI NCM when sintered at 850 °C for 12 hours in the air. In addition, the cycling performance of recycled NCM is better than the commercial MTI NCM up to 100 cycles. / Master of Science / The demand for Lithium-ion batteries has been growing exponentially in recent years due to the proliferation of electric vehicles. A large amount of lithium-ion batteries are expected to reach their end-of-life within five to seven years. The improper disposal of end-of-life lithium-ion batteries generates enormous amounts of flammable and explosive hazardous waste. Therefore, cost-effectively recycling Lithium-ion batteries becomes urgent needs. Lithium nickel cobalt manganese oxides are one of the most essential cathode materials for electric vehicles applications due to their long cycle life, high capacity, and low cost. In 2008, 18.9% of Lithium-ion batteries used Lithium nickel cobalt manganese oxides cathode material worldwide while this number increased to 31% six years later. An environment–friendly and low-cost direct recycling process for Lithium nickel cobalt manganese oxides material has been developed in this project. The goal of this project is to recycle the end-of-life manganese oxides cathode material. In order to achieve this goal, four different heat treatment conditions are investigated during the direct recycling process. From the experimental results, the cycling performance of recycled NCM is better than the commercial MTI NCM.

Fifteen curbside recycling programs in the United States, from communities representing a variety of economic, geographic and political situations, were reviewed in this study. Case studies were analyzed and discussed with respect to four areas of interest to program planners: administration, operations, promotion and evaluation. No objective rating of the programs was attempted, but approaches were reviewed with respect to their ability to satisfy the goals of the programs. Comparisons of participation rates, waste diversion rates, and costs were used cautiously because of the inconsistencies in how the data were developed from program to program. Administrative approaches found in the case studies included: (a) complete ownership of the collection and processing system by municipalities; (b) contracted service by private waste management firms; (c) contracted or subsidized service by non-profit organizations; and (d) combinations of municipal, private, and non-profit services. Operational systems were examined with respect to the effectiveness of the service in stimulating participation, given the practical, political, and budgetary constraints. Variables of operation are closely related and include: (a) which materials are collected; (b) the degree of materials separation required; (c) the type of collection vehicle(s) used; (d) collection frequency and coincidence with garbage collection; (e) the provision of in home containers; and (t) the extent of post-collection materials processing. Four categories of promotional techniques used in curbside recycling programs were discussed: (a) publicity and education; (b) personal contact; (c) economic incentives; and (d) ordinances mandating source-separation. The impacts of these techniques on participation in the case study programs were discussed. Techniques for evaluating the efficacy of curbside recycling programs were also discussed. Participation rates, waste diversion rates, and cost were reviewed with respect to current usage and recommendations were made for increasing their usefulness as indicators of the success of programs or program elements. / Master of Science