The SIMWASTE Project is a research project in the Department of Industrial Engineering at the University of Miami. The project is directed by Dr. Nurcin Celik, an assistant professor of Industrial Engineering, who has significant experience with large-scale system simulation and optimization. The project is sponsored by the Hinkley Center for Solid and Hazardous Waste Management.
Prior research conducted during the academic year 2011-2012 focused on developing a simulation-based decision-making and optimization framework for integrated solid waste management and recycling systems, analyzing both their economic and environmental aspects. Miami-Dade County is selected as the starting point for this framework where developed tool provided recommendations to the real system, pursuant to achieving the State of Florida's 75% recycling goal by the year 2020. Miami-Dade County's integrated solid waste management system (DSWM) is detailed in Figure 3 as a mass-flow diagram. The preliminary results obtained from the proposed framework provide the system with a set of near optimal resource allocation recommendations in terms of the amounts and types of the refuse to be distributed amongst current facilities. Experiments have shown that the framework successfully handled rising demand with fixed capacity, while keeping cost increases linear and maintaining capacity feasibility. The framework also successfully analyzed proposed capacity increases, although for the case study, it found them to be of minimal benefit to reduce costs or increase recycling recovery rates. The findings of the experiments also suggest that the framework would be of utility in calculating max-out dates for infrastructure capacity under dynamic demand, and in analyzing changes to retard such max-out dates.
This research is based on injuries and accidents in Florida State solid waste facilities which are rather noticeable in comparison with other states. Moreover, there is no improvement in this rate in recent years. Firstly, reported exposures of worker for facilities in all counties in Florida are collected, and then all injuries and diseases which workers can be exposed to them are categorized. Secondly, major hazards for each category are attained. These analyses are conducted by job type. Bayesian data Analysis method is applied to data; consequently posterior distributions for major hazards are achieved. Posterior distribution shows probability of hazards for the following period. Subsequently, dangerous job-type and its causes can be found. Finally, Suggestions for improvement in health and safety risks in solid waste systems are conducted, so by considering them in facilities, the exposure will be decreased.
In this research, our goal is to develop an agent-based simulation-based decision making and optimization framework for the effective planning of single stream recycling (SSR) programs. The proposed framework will be comprised of two main modules: 1) the simulation module, and 2) the fleet utilities optimization module. The simulation module is where various sources of system uncertainties will be parameterized and incorporated into the simulation model of SSR. Alternatives of SSR with respect to characteristics, cost, environmental impacts, location, materials addressed, types and capacities of the processing facilities needed, government practices, collection frequencies, convenience for public participation factors will also be evaluated at this module. In the fleet utilities optimization module, we will formulate the multi-criteria problem of allocation of limited resources. Then, the optimum combination of parameters will be determined via the embedded optimization mechanism for the state of FL to reach its 75% recycling goal. Here, the optimum solution is considered as the combination of parameter which will lead to highest recycling percentage with minimum cost and maximum benefits. Using the proposed tool, the stakeholders will be able to test several what-if scenarios in their system before reaching to a conclusion.
The objective of this study is to conduct an in-depth analysis and evaluation of advanced solid waste management technologies in order to help Florida achieve 75% recycling rate by 2020. In the scope of this study, the most appropriate advanced solid waste management technology is going to be selected for each county in Florida. Analytical Hierarchy Process (AHP) which is a multi-criteria decision-making tool is going to be used to evaluate the advanced solid waste management technologies. Finally, the recommendations for solid waste management of each county will be provided with the results obtained from the study.
Single stream recycling (SSR) is a system in which all (or almost all) recyclables, including newspaper, plastic, metals, aluminum, glass etc., are placed in a single bin for recycling. Contamination is a growing concern in SSR that significantly increases the cost and energy consumption in paper recycling at material recovery facilities (MRFs) and paper mills. Our earlier work showed that the inbound contamination rate in single stream MRFs is about 15 to 25 percent whereas the same rate is approximately 4 percent in their dual stream counterparts. Assuming the average cost of contamination in the recycling stream of an MRF is approximately $125 per ton, such contamination levels in SSR cost more than $15M per month for Florida facilities alone while saving $15 to $20 per ton on the curbside collection costs compared to multi-stream recycling. Higher levels of contamination also necessitate more energy to purify the recycled paper and make it sellable again. Here, a ton of virgin fiber paper requires about 33 million BTUs of energy to process (with about 5,601 pounds of GHG released) whereas a ton of recycled copy paper requires about 22 million BTUs of energy to process (releasing about 3,533 pounds of GHG) if the paper is recycled via a separate collection mechanism.However, when single stream with a potential of higher contamination levels is considered, these numbers may change drastically due to the additional processes for sorting, separation, and cleaning. For instance, the electricity use of pre-sorted MRF is approximately 4.7kWh to process 1 metric ton of collected materials whereas this number increases to 6.2kWh in single-stream MRFs.
The overall goals of this REMADE foundational project are to 1) identify those factors including collection modes and strategies, demographics (e.g. household participation rates in curbside collection) , input volumes, and technology which affect the contamination of inbound materials and outbound recyclable materials for MRFs designed for single-stream recycling (SSR), 2) identify and evaluate emerging technologies and practices that can further reduce inbound and outbound contamination rates of recycled products from SSR MRFs, and 3) to develop recommendations for best practices for SSR MRFs. For clarity, collection mode refers to SSR, dual-stream recycling (DSR), and multi-stream recycling (MSR); collection strategy includes municipal guidelines as to what may or may not be included in the curbside recycle bin. Identification of the key factors impacting inbound and outbound contamination rates and identification of new and emerging technologies and practices that can reduce contamination rates will enable a higher recycling rate for materials such as paper from MRFs. The project team has conducted a site visit to Rumpke Material Recovery Facility located at 1191 Fields Ave, Columbus, OH 43201.
Acknowledgement: This material is based upon work supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Advanced Manufacturing Office Awards Number DE-EE0007897.
Project Partners: RRS, AF&PA, ISRI
The objective of this study is to conduct an assessment on the contamination rates of material recovery facilities (MRFs) in Florida aiming to determine to which extent broken glass and other non-recyclables are responsible for the contamination of recovered material. Additionally, we will investigate which of the current methods that are applied to the MRFs (i.e., for sorting etc.) lead to reduced contamination rates. Finally, we will utilize on-site sampling and statistical quantitative assessment to evaluate the economics, feasibility, and value of collecting glass containers separately. This study will have significant benefits on multiple stakeholders of solid waste management system, and Floridian community at large from economic, technological, and environmental dimensions.
The objective of this study is to assess the impact of single stream recycling (SSR) on paper contamination in recovery facilities and paper mills to determine to which extent SSR is responsible for the contamination of paper. Analysis of variance (ANOVA) which is a statistical analysis technique is going to be used to assess the recovered fiber materials contamination and its correlation with the SSR programs. Finally, new and promising practices and methods to decrease paper contamination will be investigated.
