Life cycle assessment of a printed circuit board manufacturing plant in Turkey

Repair and recycling of PCBs and their components based on obsolescence index: a domestic electrical appliances case study

Population expansion and improving living standards, particularly in developed nations, have led to an increase in the usage of domestic electrical equipment, worldwide energy consumption, and CO2 emissions per capita. To limit the usage of non-reusable components and the amount of garbage that must be transferred at the end of a product's life cycle, longer-lasting electrical domestic appliances are a pillar of the circular economy. In recent years, the complexity of printed circuit boards (PCBs) used in the manufacture of modern electrical devices has increased, leading to an increase in device failures. This study focuses on the maintenance and recycling of domestic electrical appliance components and printed circuit boards. The proposed methodology for PCB repair is defined as a sequential quadratic programming (SQP) problem implemented in MATLAB environment and successfully tested to a variety of domestic appliances such as refrigerator, dishwasher and washing machine. The possibility of recycling metal parts of electronic components, which were replaced after PCBs' repair was also studied. Metals' percentage concentration of PCB electronic components for three customer's budgets considering metals and valuable metals recovery as given from the corresponding average metal recovery and calculated from different recycling procedures presented in the literature. The results of the proposed procedure in terms of valuable metals gave 38.4078 ppm of silver. We also compared the suggested procedure with other works in terms of environmental perspective considering four measures, namely the gross energy requirement (GER), the global warming potential (GWP), the acidification potential (AP), and the solid waste burden (SWB). In terms of economic perspective and considering the existence of silver (Ag) in the electronic components, the recommended method gave comparable amount of money. Finally, a comparison of different recycling works from a technical viewpoint is also conducted. Moreover, a reparability index of domestic electrical appliances is introduced to further quantify the results of the proposed algorithm.

Life cycle assessment of waste printed wiring board-derived Ag photocatalyst for sustainable fermentable sugar production

An exploratory work involving waste printed wiring board (WPWB)-derived inexpensive silver oxide (Ag₂O)-grafted silica-alumina composite photocatalyst (SAA) using quartz halogen and UVA irradiations (QHUV) (wavelength: 315 nm-1000 nm) has been revealed. The efficacy of the novel SAA photocatalyst was assessed in the synthesis of fermentable sugar (FS) by photo-hydrolysis of pure crystalline cellulose (PCC) in the QHUV-assisted batch reactor (QHUVBR), and the process parameters (5% AgNO₃ doping, 7.5% catalyst concentration, 20 min PH time, and 80 °C PH temperature) were optimized using Taguchi orthogonal array design. The BET analysis of the optimal SAA catalyst possessed high surface area (27.24 m²/g), high pore volume, and pore diameter (0.042 cc/g and 13.1684 nm), respectively, whereas the XRD indicated the presence of significant crystalline phases of Ag₂O. EDS mapping displayed the uniform distribution of silver active sites on silica-alumina support of the optimal SAA photocatalyst. The optimized parametric conditions in QHUVBR resulted in a maximum FS yield of 77.53% which was significantly higher compared to that achieved (34.52%) in a conventionally heated batch reactor (CHBR). Besides, the energy consumption was 75% more in CHBR (600 W) in comparison with QHUVBR (150 W), making the process energy-efficient and cost-effective. The environmental sustainability could be ascertained from the life cycle assessment (LCA) study in terms of low climate change, ionizing radiation, metal depletion, human toxicity, and other potential indicator values.

Alternative Materials for Printed Circuit Board Production: An Environmental Perspective

This article investigates the potential environmental impacts of four-layer printed circuit board (PCB) production from cradle to grave. The study starts with a lifecycle assessment of conventional PCB production. Then, the alternative materials of polyethylene terephthalate (PET), polylactic acid (PLA)/glass fiber composite and paper are investigated for the substrate. A conventional PCB adopts copper as the conductive material and requires an etching process. The environmental impacts of changing the conductive deposition method to an additive method by printing silver nanoparticles is studied. In a conventional PCB, electricity generation contributes 41% of the global warming potential (GWP) and 38% of the abiotic resource depletion (ADP), in the fossil category. By applying an additive manufacturing method, the GWP of PCB manufacturing can be reduced to 14% of that of the conventional method. A sensitivity analysis of silver recycling illustrates that a 40% higher silver recycling rate would decrease the GWP of silver material by about 48–60%. Uncertainty in the energy consumption of PCB production would alter the environmental impacts; however, even with the most conservative energy consumption in a conventional PCB production method, the environmental impacts of the additive method are about five times lower than those of conventional PCB production.

Environmental and economic performance analysis of recycling waste printed circuit boards using life cycle assessment

Recycling precious elements from the electronic waste could be an environmental friendly way to avoid likely ecological damages caused by leaching of heavy metals and toxic elements as well as an economically attractive option to recover valuable materials that would otherwise be wasted. This research assessed the environmental and economic performance of recovering nine metal elements (aluminum (Al), copper (Cu), gold (Au), lead (Pb), nickel (Ni), silver (Ag), tin (Sn), zinc (Zn), and iron (Fe)) and two non-metal materials (resin and glass-fiber) from the waste printed circuit boards (PCBs), one of the vital components of electronic-waste (e-waste). SimaPro software was used to assess the environmental performance of recycling waste PCBs. Data were collected from recycling plants in Taichung City, Taiwan, and Eco-invent database was also used in the study. The impacts of metal recycling from PCBs were compared with the impacts caused by the mining of respective metals from their natural ores. Among the analyzed elements, only the recovery of Au from waste PCBs proved to have less environmental impacts than the mining from the natural ore. Among 16 environmental impact categories (ILCD midpoint 2011+ method of impact analysis) considered in the present study, cancer and non-cancer human toxicity were the most affected categories followed by minerals, fossils, and resource extraction. However, the economic analysis showed that the recycling of all elements from waste PCBs had a net positive benefit. When considering both the environment and economic performance, the recycling of Au proved to be a beneficial option.

Sustainability

This review on Sustainability covers selected 2018 publications on the focus of sustainability. It is divided into the following sections: (a) Water quantity; (b) Water quality; (c) Climate change and resilience; (d) Planning and ecosystem evaluation; (e) Life cycle assessment (LCA) applications; (f) Sustainable management; (g) Sustainability and asset management; (h) Sustainability in wastewater treatment; (i) Sustainable water and wastewater utilities; (j) Sustainable water resource management.

Life cycle assessment of a large water treatment plant in Turkey

The objective of this study is to assess the environmental sustainability of a large water treatment plant through life cycle assessment (LCA) approach. This study is a pioneering one that explores the environmental impacts of a water treatment plant in Turkey by using the data collected from an actual plant. Decision makers of the treatment plant under investigation, operators of similar installations, and the scientific researchers that work on LCA of water treatment facilities are defined as the target audience. GaBi software is used for the LCA model, and CML 2001 method is adopted to calculate the results given per 1 m³ water ready to be distributed to the city. The plant serves about 2,600,000 people generating a maximum potable water flow rate of 400,000 m³/day. In the facility, 0.57 kWh of electricity is required to obtain 1 m³ of water. Of this total electricity consumption, 85% is allocated to inlet and outlet pumping stations. The results denote that the environmental impacts are dominated by electricity consumption that in turn depends on the energy source/s adopted. Sensitivity analysis on energy sources reveals the following outcomes: In case of using hard coal as energy source rather than grid mix, impacts are increased apart from freshwater aquatic ecotoxicity potential, ozone layer depletion potential, and abiotic depletion potential elements. Once solar panels are used instead of grid mix, values for all impact categories except abiotic depletion potential elements and human toxicity potential are lowered. The usage of wind turbines in place of grid mix results in 29 to 84% reductions in all investigated impact categories. The best option to decrease the environmental impacts is attained when energy is generated using wind turbines. As pumps having 90% efficiency replace the pumps with 60% efficiency, reductions ranging from 15 to 24% on all impact categories are obtained. The work performed for this study should be further pursued to obtain more representative inventory data for countries with scarce LCA studies.