Materials Science and Engineering Commons^™

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

Integrating Steel Slag Aggregates Into Asphalt Paving By Harmonizing Availability, Quality, Economics, And The Environment, Timothy R. Murphy

Theses and Dissertations

This thesis provides guidance on how to balance matters related to the environmental stewardship, market sources, origin and uses, material properties, performance, and economic impact of using slag materials in pavements. The literature on this topic provides numerous references on the use of slag materials for specific applications, and this thesis aims to make use of those references along with other data from the author to describe slag materials from a holistic perspective and provide some suggestions for balancing several factors that impact optimal use of this resource within pavement structures. Discussion is given to the increased importance of recycling …

Simultaneous Hydrogen And (Nh4)2So4 Productions From Desulfurization Wastewater Electrolysis Using Mea Electrolyser, Ju-Cai Wei, Lin Shi, Xu Wu

Journal of Electrochemistry

It is preferred to simultaneously recover resource and energy from waster. Sulfur dioxide, SO₂, a common air pollutant, a potential energy resource, is a key link to sulfur nature circulation. SO₂ can be conversed to NH₄HSO₃ and (NH₄)₂SO₃ during the ammonia desulfurization process, which can be used to produce (NH₄)₂SO₄ fertilizer. For high quality (NH₄)₂SO₄ fertilizer and high heat transfer efficiency of the evaporative crystallization, HSO₃- or SO₃2- needs to be oxidized to form SO …

Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar

Williams Honors College, Honors Research Projects

The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.

The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …

Study On Electro-Sorption Of Heavy Metals And Sulfamethoxazole On Activated Carbon Fibers, Wen-Jun Zhao, Bing-Xin Jia, Ya-Nan Zhang, Jiu-Nian Guan, Jiao Qu, Ying Lu

Journal of Electrochemistry

To study the optimal removal condition, adsorption mechanism and comparative analysis of the three typical cationic pollutants, i.e., Zn(II), anionic pollutant Cr(VI) and molecular pollutant sulfamethoxazole (SMX), using self-made upflowed electro-sorption device for adsorptions of above three pollutants by modified activated carbon fiber were researched. The activated carbon fiber (ACF) was modified by hydrochloric acid. The ACF morphology and structure before and after modification were characterized by SEM, BET and FTIR. The characterization results show that the modified ACF had fewer surface impurities than the modified surface and the gully is more obvious, the specific surface area was increased by …

Development And Characterization Of Polyethylene Terephthalate (Pet)-Cotton Natural Fiber-Reinforced Composites From Waste Materials, Israel Alejandro Carrete

Open Access Theses & Dissertations

Unprecedented levels of production and consumption have caused a rapid exhaustion of the Earth's virgin resources, which is coupled with a fast accumulation of contaminants in the form of solid waste, especially in landfills. Two significant landfill constituents come from textile waste and discarded plastic bottles. Since there is a finite amount of space that can be feasibly used for landfills, solutions that make use of these post-consumer products are imperative. This study presents one possible solution by using surface modifications of cotton fibers to produce a natural fiber-reinforced polymer composite (NFRPC) from post-consumer textile waste and polyethylene terephthalate (PET) …

Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part Ii: Development Of The Processes For The Recovery Of Copper From Printed Circuit Boards (Pcb), Zeljko J. Kamberovic

Zeljko J Kamberovic

Rapid technological development induces increase of generation of used electric and electronic equipment waste, causing a serious threat to the environment. Waste printed circuit boards (WPCBs), as the main component of the waste, are significant source of base and precious metals, especially copper and gold. In recent years, most of the activities on the recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled compared to conventional pyrometallurgical processes. In this research essential aspects of the hydrometallurgical processing of waste of electronic and electrical equipment (WEEE) using sulfuric acid …

Hydrometallurgical Process For Extraction Of Metals From Electronic Waste-Part I: Material Characterization And Process Option Selection, Zeljko J. Kamberovic

Zeljko J Kamberovic

Used electronic equipment became one of the fastest growing waste streams in the world. In the past two decades recycling of printed circuit boards (PCBs) has been based on pyrometallurgy, higly polluting recycling technology whic causes a variety of environmental problems. The most of the contemporary research activities on recovery of base and precious metals from waste PCBs are focused on hydrometallurgical techniques as more exact, predictable and easily controlled. In this paper mechanically pretrated PCBs are leached with nitric acid. Pouring density, percentage of magnetic fraction, particle size distribution, metal content and leachability are determined using optical microscopy, atomic …

Optimisation Of Ferriferous Dust And Mud Preparation Acts From Iron And Steel Production On Purpose Of Returning To Primary Processes, Zeljko J. Kamberovic

Zeljko J Kamberovic

In this paper detailed characterization of ferriferous dust and mud which originated from aglomerization, blast- furnace and converter process in Iron-works Smederevo were shown. Optimization of method peletization was conducted in variably conditions (different moinsture content, changing of time of peletization and type of binder). These palets were submitted to examination of resistance on impact and pressure, and their behavior was confirmed returning in sintering process in semiindustrial conditions. Ideally-technological solution for plant preparation of dust and mud in Iron-works Smederevo was recommanded. That solution should contribute to improvement of techno-economic parametars of aglomeration and blast- furnace process, as well …