The waste management technologies are critically important when we try to visualize a sustainable society. In the growing world, a huge share of the output of the industrial processes and society living is waste, which has a dramatic impact on the environment. Turning the "linear" production economy to a "closed-loop" no-waste economy is a primary task underlined by sustainable design principles. And new designs and new technologies can have a big role in this process both at the local and national level.
There are two issues in resource management story: (1) resource conservation and (2) pollution prevention. When natural resources are extracted and turned into products via a manufacturing process, they become involved in a linear lifecycle - cradle-to-grave. If there is a constant demand for the product, more resources will be extracted, more product manufactured, and more end-of-cycle refuse generated. The limitation associated with the first issue is eventual depletion of the resource (especially if it is non-renewable). The limitation associated with the second issue is reaching the environmental capacity for holding or absorbing the "death" products. These limitations create potential for crisis, which has to be addressed in order to reach system sustainability.
In this lesson, we will take a look at some technologies that seem promising along those lines.
By the end of this lesson, you should be able to:
Website: Types of Composting(link is external) [3], US Environmental Protection Agency, 2013.
If you have any questions while working through this Lesson, please post them to our Message Board forum in Canvas. You can use that space any time to chat about course topics or to ask questions. While you are there, please feel free to post your own responses if you are able to help out a classmate.
"In order for something to become clean, something else must become dirty…
But you can get everything dirty without getting anything clean." --Imbesi's Law of the Conservation of Filth with Freeman’s Extension (Dictionary of Proverbs, Ed. Kleiser, S.B.N. A.P.N. Publishing 2005)
The starting point for this lesson is a general overview of the waste management industry. The following reading will introduce you to the main issues related to waste generation, disposal, recycling, and related problems.
Solid Waste Technology & Management, Christensen, T., Ed., Wiley and Sons., 2011.
Chapter 1.1. Christensen, T.H., Introduction to Waste Management, pp. 3-16. (See E-Reserves in Canvas.)
After this reading, you should be able to answer the following questions:
So, how is the problem of waste disposal currently handled? There are a number of established technologies that help remove discarded materials out of our sight. Some of those discarded materials are reused in some form, but much larger amount is dumped or buried in the environment, which creates contained pollution. But is it really contained? And is that practice sustainable?
Watch the following video, which tours waste management facilities near San Francisco. That gives you an idea of the scale of waste accumulation in urban areas and shows what it takes to treat it:
This is how numerous facilities around US currently operate. For the most part, it is so-called cradle-to-grave scheme, when discarded products and waste are recycled to typically lower grade material (i.e., down-cycled) or packed in a landfill. According to EPA, more than 50% of generated solid waste in the US is discarded, i.e., disposed of in the landfill. The following material is an EPA document showing some concrete numbers, which demonstrate how developing recycling technologies help reverse the trend in waste generation.
Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 201 [1]2, US EPA 2012.
While reading, look to understand all the diagrams representing the data, and specifically look at the data in Table 1, which gives you an idea on the efficiency of recovery of certain types of waste materials.
Compare Figure 4 with data in the book chapter you read in the beginning of this section (diagram 1.1.5). How does USA rank by waste treatment ratio among European countries?
Answer the following question to check your learning of this section.
What are the five levels of waste management hierarchy? (Input answers below.)
1.
Click for answer.
As we can see from the previous page of this lesson, there are a number of conventional methods of waste treatment which depend on the system scale and type of waste. However, not all of them fit in the sustainability picture. For example, such common methods as incineration or landfilling are not sustainable solutions because, while eliminating problem in one zone (for example, human residence or industrial facility), they create additional pollution in the other (atmosphere, soil, aquifers, natural habitat). The purpose of recycling is to minimize or completely avoid sending waste to landfill or incinerator.
There are two major stages in recycling strategy: collection and processing. Both may consume resources and limit the process efficiency. The main recyclables are metals, plastics, glass, paper, and wood. Those materials are common in consumer products, so the public needs to be involved in the process. Public acceptance is important for the success of recollection of those recyclable materials (for example, public awareness and availability of collection points in public places plays a role – see image above). At the stage of processing, the question of recyclability is often related to the product design. How difficult and expensive is it to retrieve those materials from the product? You need to get those materials separated in a pure form in order to make them reusable in the same or new products.
Some skeptical questions we can often hear from the public are: Is recycling really worth it? Would the energy spent on recycling collection, transportation, and processing offset the benefits of the process? Would the emissions associated with that recycling exceed the overall environmental impact of the original trash? Those questions are good to contemplate on and the answers would require a deeper look into the lifecycle of materials.
To refute those commonplace skeptical arguments, the Environmental Protection Agency (EPA) provides some clear evidence on the benefits of recycling to the planet. Here are just a few facts:
It is important to realize that recycling is far from being a universal remedy to the world’s pollution problems, however most experts say it is an important component in the systemic response to the environmental global change, pollution, and other serious issues of this century. [Howard, B.C., 5 Recycling Myths Busted, National Geographic [9] 2018].
Recycling indeed helps to save energy, resources, and prevent greenhouse gas emissions on the lifecycle scale. You can look up more numbers on the Popular Mechanics website [10] which compares recycling rates for aluminum, glass, newsprint, and some plastics, and links those data to market trends.
As seen from this information, an important factor responsible of viability of recycling business is the cost of the new material production. For example, production of virgin aluminum by bauxite mining is so energy-demanding that recycling of drink cans is very economically attractive. On the contrary, glass recycling, while technically simple, does not bring such high benefits, just because making new glass from silica sand is a relatively cheap technology.
Another factor that affects the viability of recycling system is collectability. Plastic recycling is quite profitable, with 76% energy savings compared to new plastic production. However, the case of polystyrene containers shows that if there is no technology to efficiently separate them from other plastics, process fails.
The bottom line here is that recycling heavily relies on development of new advanced technologies and approaches for material processing (without quality loss), collection, and sorting recyclables.
Unfortunately, many cases of recycling only help postpone permanent waste generation. This happens if an original material gradually loses its quality while being recycled and cannot return to the same manufacturing process. It has to be reprocessed to lower-grade products, which are not necessarily recyclable. For example, recycling of polyester soda bottles results in obtaining polymer fibers, which may be supplied to a carpet manufacturer. Carpet, however, is not easily recyclable since it is a more complex product. Polymeric fabrics are combined with other organic products and adhesives to make the final product. Separation of pure components after its use is not feasible; hence, the used carpet becomes a landfill material. This way of recycling, when a material lives a few lives but becomes less and less usable or pure or safe along its way to the landfill, is often termed "downcycling". In terms of sustainability, it means being "less bad", but still not good enough.
At this point, it would be appropriate to look at different concepts in material recycling.
Open-loop recycling basically means that a material is not recycled indefinitely and is eventually excluded from the utilization loop and becomes waste. The diagram in Figure 5.1. shows a material flow through the linear (open-loop) system. In this representation, stocks are shown with rectangular boxes, and transforming processes are shown by hexagon boxes.
In Figure 5.1. below, we see that natural resources extracted from the environment are transformed into a product via manufacturing process. After its use, the product may be discarded as one of the outputs: (a) whole product that is not needed anymore, (b) whole product that became obsolete (although still functional), (c) non-functional or old product because of its limited lifetime, (d) recyclable / reusable parts or scrapped materials, and (e) non-recyclable refuse. Those outputs enter one of the post-use channels – reuse, recycle, and garbage disposal, the latter contributing to the landfill. Reuse channel is usually limited, just postponing garbage disposal. Recycling loop results in producing another material, which is typically of lower grade and purity than the original material. It may be transformed further into a different product, which after use creates similar outputs. In the long run, a small part of the original resource may be stuck in the loop, but the majority of it becomes disposed of.
The bottom line is: even if recycling and reuse are involved, eventual down-grading renders material non-usable, and it contributes to waste generation in the end of the lifecycle. Open-loop recycling postpones disposal and slows down extraction of new natural resources, but does not provide an ultimate solution to the problem.
Closed-loop recycling is a more sustainable concept, which means that recycling of a material can be done indefinitely without degradation of properties. In this case, conversion of the used product back to raw material allows repeated making of the same product over and over again.
A few things to consider:
The other part of closed-loop recycling concept is biodegradable disposal. Everything that cannot be recycled or comes as a by-product in the manufacturing process should return to the environment with no harm. The diagram in Figure 5.2 summarizes the above considerations. While starting from the same extraction, manufacturing, and use stages, the outputs in the closed-loop scheme become equally usable resource for the manufacturing chain. Greater fraction of materials should be designed for recycling and reuse. The refuse that is inevitable is biodegradable and brings no harm when returned to the environment.
In any sustainability scenario, closed-loop approach is the goal. But it would take radical changes and innovative thinking at the level of product and process design.
To a greater extent, this closed loop thinking is advocated in the book of William McDonough and Michael Braungart “Cradle-to-Cradle”. The authors suggest that every product and all packaging should have a complete closed-loop cycle mapped out for each component, i.e., pathways should be identified for each component to either be recycled indefinitely or to return to the natural ecosystem.
When closed-loop resource management is successfully implemented, we ideally should have zero waste produced, as all products at the end of their lifecycle become assimilated by either technical or natural systems to their benefit. In a wider context, zero waste thinking also covers zero emission and zero water pollution. Such targets seem ambitious and require careful life cycle analysis of all steps.
Zero waste concept responds to the principle #6 of sustainable design, "Eliminate the concept of waste. Evaluate and optimize the full life-cycle of products and processes, to approach the state of natural systems, in which there is no waste" [The Hannover Principles., 1992]
"Zero waste philosophy encourages the redesign of resource life cycles so that all products are reused. No trash is sent to landfills and incinerators. The process recommended is one similar to the way that resources are reused in nature." [Source: Wikipedia Zero Waste Article [11] - read this Wikipedia article to learn more about the historical development of this concept].
Zero-waste strategy supports sustainable development through the following pathways:
Source: Zero Waste Alliance
It should be noted, however, that zero-waste concept is not equivalent to closed-loop recycling in technical sense. It involves and relies heavily on the design of systems for reuse of products and resources without additional energy and labor expenditures, which are usually required for classic recycling.
The following reading materials contain more information about what materials are recyclable and what happens to them afterward. The article is not freely accessible online, so it is only included as supplemental reading. You may be able to check out a hardcover copy of the Encyclopedia from a local library.
Book Chapter: Lawrence, S.R. et al., Recycling Technology [12], McGraw-Hill Encyclopedia of Science and Technology, 2007, 10th, ISBN 9780071441438, v. 15, pp. 262 - 270
This article provides quite a complete list of materials subject to recycling. It also gives you an idea what methods are used to process those materials and also what further manufacturing chains or markets they enter afterwards. Take a note of those connections.
Book Chapter: McDonough, W. and Braungart, M., Cradle to Cradle. Remaking the Way We Make Things, North Point Press. New York, 2002. Chapter 4: Waste Equals Food, pp. 92-117. This document discusses the concept of sustainable development.
This is a really engaging reading that will make you understand the closed-loop philosophy better. A nice illustration of what design challenge may involve is described on p.105 in the DesignTex case.
We understand that recycling materials from the waste stream helps to conserve resources. But the question often arises: How much material can be actually recovered, and is it worth spending energy and labor for it, or it is easier to extract fresh material from the environment? A useful metric to characterize technical performance of a recycling line is recycling efficiency. The general approach to estimate efficiency is as follows:
Consider the case of recycling Pb-acid batteries. Input will include lead metal (Pb) together with liquids and other solids contained in a battery and also the external jacket. Let us count recovered Pb as useful output, but any chemicals that cannot be salvaged and must be disposed off are not included. Then efficiency of lead recovery can be estimated as: η = mPb(out) / mi(in) x 100%
Let us imagine that a small recycling facility treats 13,000 kg of old batteries per year. If the amount of the recovered lead is for example 7,000 kg per year, then
η = 7,000 / 13,000 × 100% = 54%
That means that the other 46% of material supplied to the recycling process is lost or discarded (e.g., non-recyclable acid and other chemicals, slag, etc.). Note, the above numbers are randomly picked and used merely for example.
100% efficiency is possible only in the ideal case when no waste is sent to the landfill or incineration.
Source: adopted from the method described in the EU Commission Regulation 6/11/2012
Food waste accounts for 14.5% of all generated waste in the US according to EPA report, and only a small portion of it is recovered (1.6%). At the same time, food waste contains loads of nutrients that can be returned to the environment, but it should be done the right way. Disposing of the organic waste in the landfill results in the generation of methane, which can pose a threat or contribute to the greenhouse effect. Hence, developing composting technologies is an important part of a sustainable waste management system.
Compost is a stable organic mixture resulting from the breakdown of organic components; it is typically dark brown or black and contains humus which provides a soil-like, earthy smell. Compost is widely used as fertilizer and soil amendment in agriculture. It is created by piling organic wastes (garden waste, leaves, food waste, manure) with bulking agents (e.g., wood chips) to provide an environment for anaerobic bacteria and fungi to manage the chemical decomposition process. Compost is stabilized through maturation and curing process.
According to US EPA, there are a number of benefits of the composting process. These include:
Certain physical conditions need to be provided for proper composting process. There are different types of processes, which are overviewed in the following reading.
EPA Website: Types of Composting [3], US Environmental Protection Agency, 2013.
Watch this short video that illustrates an industrial-scale composting facility in the UK. This is only one of the ways to do it. Which type of composting (from those listed by EPA) is this facility using?
While having obvious benefits, composting is far from being environmentally clean. When organic components are mixed and concentrated during waste collection, they create aggressive gases and liquid effluents, which should be carefully controlled. In the diagram in Figure 5.3. The side inputs and outputs accompanying the composting process are shown. The pre-composting weighing and pre-processing stages generate liquid leachate, gas exhausts, and solid residue as by-products. The composting stage requires input of air and water, while generating more potentially polluting exhaust and effluents. Some of the residue is reusable, but some is not and need to be disposed of as non-recyclable waste.
Criteria that usually play a role in environmental and economic assessment of composting process are: energy use, transportation, land use, air quality. An example of multi-criteria analysis is presented in the “composting versus landfill case study, referenced below:
Book Chapter: Solid Waste Technology & Management, Christensen, T., Ed., Wiley and Sons., 2011. (See E-Reserves via Canvas.)
Chapter 3.2. Christensen, T.H., LCA in Waste Management: Introduction of Principle and Method, Section 3.2.4.1. pp. 153-155.
Please study this example, and while reading try to get answers to the following questions:
Book Chapter: Solid Waste Technology & Management, Christensen, T., Ed., Wiley and Sons., 2011
Chapter 9.2. Krogmann, U., Korner, I., Diaz, L., Introduction to Waste Management, pp. 533-565.
Interested in more technical details of composting technology? Refer to this reading material, which contains much of the technical information needed for specialists in this area.
This book is available online through PSU Library system.
There are reasons to separate the electronics waste stream:
Electronics recycling, computers for instance, is essentially a process of breaking down the final product back to components (some of which can be reused) and initial raw materials (such as copper, gold, silver, other metals, plastics). Because of significant load of technological product with heavy metals and toxic compounds (e.g., mercury, cadmium, lead, flame retardants), discarded electronics are classified as hazardous waste. Hence, recycling also requires strict measures of environmental safety.
The following article provides a concise overview of current practices to handle electronic waste in the United States and specifically investigates the health implications and policies required to mitigate the negative impacts. The article contains statistic data on specific parts and components in electronics that are subject to recycling and shows their linkage to chemical resource lifecycles:
Seeberger, J., et al., Special Report: E-Waste Management in the United States and Public Health Implications [17], Journal of Environmental Health, vol. 79, pp. 8-16 (2016).
This paper is available online through the Penn State Library system. Students registered for the course can also access it in Canvas.
Try to find the answers to the following questions, while reading:
There are companies and government programs that take on the challenge of responsible recycling of electronic products; for example, watch this short video about how Liquid Technology helps companies manage their e-waste while protecting the environment from hazardous materials:
However, currently existing programs of sorting / disassembly are hardly sufficient. The problem is that current computer and other electronic products are not designed to be recycled. End-of-life disassembly and recovery of pure materials is a tedious and expensive process. Few companies manage to build an effective infrastructure for electronic recycling. Even if responsible recycling practices exist, they hardly keep up with growing market for electronics and accelerating e-waste accumulation pace.
Unfortunately, there are businesses that find it more profitable to export the electronic waste overseas to developing countries. This practice, highly non-sustainable on the global scale and harmful to local population and environment, is an ugly illustration of shifting the environmental burden from one part of the global system to another:
For example, this video contains graphic illustrations of such irresponsible “recycling”.
So, what are possible sustainable solutions to address the root of the e-waste problem?
"Instead of assuming that all products are to be bought, owned, and disposed of by “consumers”, products containing valuable technical nutrients – cars, televisions, carpeting, computers, and refrigerators, for example – would be preconceived as services people want to enjoy. In this scenario, customers would effectively purchase a service of such a product for a defined user period – say, then thousand hours of television viewing, rather than the television itself. They would not be paying for complex materials that they won’t be able to use after a product’s current life. When they finish with the product, or are simply ready to upgrade to a newer version, the manufacturer replaces it, taking the old model back, breaking it down, and using its complex materials as food for new products." [McDonough and Braungart, 2002]
Currently in the US, many states have active policies to regulate the e-waste. Different models suggest imposing fees to finance e-waste recycling onto various entities – consumers, manufacturers, municipalities. There are also different mechanisms to facilitate collection and processing of the e-waste. Some examples are given in the following reading:
Want to learn more? This following article provides a detailed overview of materials to be recovered from the consumer electronics and methods involved in management of this growing waste stream:
Solid Waste Technology & Management, Christensen, T., Ed., Wiley and Sons., 2011. Chapter 11.2. “Waste Electrical and Electronic Equipment”, Bigum, M. and Christensen, T.H., pp. 960-968.
This book is available online through PSU Library system.
Apparently, present-day computers are not perfectly designed for end-of-life recycling. Can we estimate the efficiency of recycling of an average desktop computer?
According to the approach outlined in Section 5.3 of this lesson, can you calculate the efficiency of recycling of an average desktop computer based on the following data?
Input / Output | Component | mass | |
---|---|---|---|
input | mass of the computer placed in the recycling bin | 6000 g | |
useful output | mass of salvaged old components for reuse | fan | 100 g |
wires | 300 g | ||
power supply | 1000 g | ||
memory chips | 100 g | ||
cpu | 200 g | ||
optical drive | 500 g | ||
mass of salvaged raw materials for making new components | Cu | 200 g | |
Al | 300 g | ||
steel | 600 g | ||
Precious metals (Au, Ag) | 1 g | ||
recyclable plastics | 900 g |
Click for answer.
Efficiency can be estimated as
h = total mass of all useful output materials / total mass of material submitted for recycling = =(100+300+1000+100+200+500+200+300+600+1+900) g / 6000 g x 100% = 70% ]
Solar power is probably the fastest-growing market in the world. According to Solar Energy Industries Association [22] (SEIA), in the past decade, solar power industry experienced an average annual growth rate of ~59%. An estimated 500,000 solar panels were installed globally every day in 2015. If we think of rooftops, a typical American home would require 28 to 34 solar panels to cover its power consumption. The U.S. Department of Energy forecasted that by 2050, the U.S. will have cumulatively installed 700 GW of solar, or hundreds of billions of PV modules [Mulvaney, 2015].
But here is the question: What will happen to the billions of those solar panels now spreading across the globe at the end of their useful lives?
On the average, solar photovoltaic (PV) modules have a useful lifespan of 25-30 years, so with the current growth rates, the first peak of PV waste can be expected around 2030. And there is still some time to plan ahead. Now, as we know how externalities have magnified due to the lack of foresight with fossil fuels, there is an opportunity to do things right with solar.
As the photovoltaic panels contain a variety of valuable metals and materials, which are mined and refined at increasing rates, it is imperative to create recycling methodologies, infrastructure, and policies to maintain the flow of those materials within the industry. This important action would address two problems – waste regulation and resource depletion.
What are the current US domestic programs designed to address the growing PV waste flow? Until recently, the regulations on PV waste did not exist in the USA, except California. However, things have to change soon. In lieu of introduction to this problem, the video below talks about some of the emerging options and initiatives, many of which utilize the successful experience of the European recycling programs:
These two short articles outline some options for PV recycling available in the US and in Europe. For example, “PV Cycle, a European solar panel recycling association, developed a mechanical and thermal treatment process that achieves 96% recovery rate for silicon-based photovoltaic panels.” This sounds quite impressive! “The remaining 4 percent is utilized in an energy recovery process, using a waste-to-energy technology.”
Web Article: Lozanova, S., Are Solar Panels Recyclable, Earth 911, 2018. URL: https://earth911.com/eco-tech/recycle-solar-panels/ [4]
Web Article: Marsh, J., Recycling Solar Panels in 2018, EnergySage, 2018. URL: https://news.energysage.com/recycling-solar-panels/ [5]
There are a number of recyclable components included in PV module – some of those are rare, and some of those are toxic and thus require a proactive plan for recycling. Crystalline Si PV modules, in addition to silicon, contain materials such copper, aluminum, silver, and glass. CdTe PV modules contain cadmium, steel, and copper. Metal components are usually much more expensive than non-metal materials, and extracting them during recycling process and reusing in manufacturing brings sensible economic benefits. Materials such as silicon wafers are critical to recycle, as a substantial amount of energy is spent to purify them for use in PV modules. Thin-film modules contain such elements as tellurium, indium, gallium, and molybdenum, which are in limited supply in the Earth’s crust. Indium is the element that will face resource use competition between solar and flat-screen displays. [Williams, B., 2016]
The following webinar (International Solar Energy Society - ISES) presents an extended overview of PV recycling practices, policies, and current research innovations around the world. The first talk is more on the legal background and policies existing in different countries. The second presentation explores the way to incorporate PV panel reuse practice in circular economy. The last presentation in the webinar goes deeper into the weeds of the recycling process itself. You will see the actual equipment used for the mechanical, chemical, and thermal extraction of materials from the discarded panels.
If you want more insight in the process of recovering of specific elements and design of the material flow, this article provides a comparative analysis of recycling of two types of PV panels - Deutsche Solar and First Solar - including LCA considerations and cost analysis.
Journal publication: Kim, S., Jeong, B., Closed-Loop Supply Chain Planning Model for a Photovoltaic System Manufacturer with Internal and External Recycling, Sustainability 2016, 8(7), 596.
URL: https://www.mdpi.com/2071-1050/8/7/596 [29]
The presented analysis and modeling shows that using the external recycling facilities as material source, the PV manufacturers can save on some costs. Joining a recycling association decreases the total cost of c-Si panels by 55.28% and CdTe panels by 2.28%.
Do you know what programs and policies for electronic and PV recycling exist in your town, city, or area? Do residents and business choose to use them? Why yes or why not?
Mulvaney, D., Act Now To Handle The Coming Wave Of Toxic PV Waste, Solar Industry Mag 2015. Accessible from URL: https://solarindustrymag.com/ [30]
Williams, B., Photovoltaic (PV) Recycling, Final Project, EME 807 Technologies for Sustainability Systems, Renewable Energy and Sustainability Systems (RESS) Program, Penn State University, 2016.
Reuse is the second level of the national solid waste management hierarchy. Reuse is simply repeated using a product or component in its original form. For example, using a glass milk bottle multiple times within the producer – customer chain (instead of using a plastic bottle).
Reuse also means that materials and products are redistributed from one who no longer needs them to those who can still find use in the items. The benefit of reuse is not only in conservation of valuable natural resources, but also in getting materials and products to disadvantaged people and organizations.
US EPA provides grant funding to Reuse Development Organization Inc. (ReDO), a non-profit organization whose mission is "to promote reuse as an environmentally sound, socially beneficial, and economical means for managing surplus and discarded materials. The ReDO company website [31] provides some background on the issue.
Here are a few examples of successful material reuse programs, which attempt to divert the flow of useful resources from the waste stream:
This week, in Lesson 5, you are learning about various methods to minimize waste and to avoid putting that additional burden on the environment. Recycling is often thought of as a smart way to deal with waste – something we have to do to reduce the mess that has already been made. However, the same as with green chemistry principles, thinking is being shifted now from dealing with consequences of dealing with the root cause. In fact, recycling should become a part of the product design, so that its efficiency is maximized, and maximum of valuable material included in the product is recovered. In this case, more focus is put on salvaging the resource, rather than just keeping stuff off the landfill.
This way of thinking becomes even more urgent when we realize that for new emerging technologies, we need significant amounts of earth’s minerals that are actually limited. Those critical minerals and materials become strategic stocks for industries producing electronics, batteries, clean energy, aerospace, and other technologies that are going through massive scale-up. Design of closed recycling loops for those minerals is also a strategic task for manufacturers, if they plan staying in business for prolong period of time. For example, recycling metals such as Li, Co, Ni, Mn, rare-earth metals, graphite will be critically important for meeting the demands for energy storage and renewable energy. Thus, recycling becomes not only a key part of waste management, but also an integral link in the so-called circular economy.
Circular Economy [36] is a relatively new term, which I wanted to put on your radar in this lesson. It builds upon the zero-waste concept, but actually goes beyond that. While encompassing stages of product design, and recycling technology, it also assumes establishing new sustainable supply chains for critical materials and strong partnerships among all players in the circle.
The concept of circular economy is not something we suddenly invented. In the nature, we see cyclic processes for matter and energy transformation functioning for millennia. This is the system where waste (as we understand it in society) does not exist! One good example to give here is a tree!
The tree absorbs water and nutrients from the soil and grows branches, leaves, fruits, and seeds. The fruits and seeds become food for animals and birds. Leaves are engaged in the photosynthesis producing oxygen, which is used for breathing by organisms. When leaves fall to the ground and decompose, the resulting organic matter enriches the soil, which sustains the growth of other plants, and the tree itself. And then the cycle starts all over again.
Speaking of biomimicry: can we design a technical supply chain system in which all the outputs from one segment of the system become the inputs to another segment of the system, just like it happens in biological environment?
Please watch this short video to learn more about the circular economy concept:
"Circular Economy in Detail", Ellen Macarthur Foundation, URL: https://archive.ellenmacarthurfoundation.org/explore/the-circular-economy-in-detail [36], Accessed: 2021.
On the website linked above, scroll down through the presentation slides to learn the key principles and definitions of the circular economy concept. Think of an example of the process or product that is already using these principles to effectively save the mineral resources. Think of another example - a process that urgently needs innovation to prevent fast resource depletion. Usually, resource depletion problem rises upon the scale-up of a particular process.
This lesson contains a significant amount of information on existing and developing methods of resource conservation and waste treatment. This information is mainly related to dealing with municipal waste and does not cover special types of waste such as nuclear or agricultural waste. Wastewater and sewage treatment is a separate topic that will be addressed in the next lesson. The general thought that summarizes this lesson is that treatment of waste is a dirty and expensive business - it is better to prevent it than clean it up. New technologies that would change the situation to a more sustainable world must involve transformative design innovations that increase the recyclability and biodegradability of the waste stream outputs. Life cycle thinking and modeling will help to identify the best scenarios for sustainable actions.
Type | Assignment Directions | Submit To |
---|---|---|
Reading | Complete all necessary reading assigned in this lesson. | |
Discussion |
Clean-up Innovations. 1. Search the web for innovative ideas aimed at efficient waste disposal or removal. 2. Post the link to the story or source. 3. Briefly explain the principle of technology or approach. 4. Express your own opinion on the promise of this idea. This search can be related to any scale of waste disposal or cleanup (from industrial to small household or community wide). Let us stick to the solid waste area (wastewater treatment is a separate topic). It can be both a technological system or simply a strategy, but it should provide a way to make our living environment cleaner. |
Canvas: Lesson 5 Module |
Activity |
For this assignment, choose one of the two research articles (available via PSU Library or as PDF in Module 5 in Canvas): 1. Jin, H., Frost, K., Sousa, I., Ghaderi, H., Bevan, A., Zakotnik, M., and Handwerker, C., Lifecycle Assessment of Emerging Technologies on Value Recovery from Hard Disk Drives, Resources, Conservation, and Recycling, 157 (2020), 104781. 2. Hu, Q., et al., Biochar Industry to Circular Economy, Sciences of the Total Environment, 757 (2021), 143820. Instructions:
For more details, please see Lesson 5 Dropbox and Worksheet in Canvas. Deadline: Wednesday (before midnight) |
Canvas: Lesson 5 |
Solid Waste Technology & Management, Volume 1 & 2, Christensen, T., Ed., Wiley and Sons., 2010.
McDonough, W. and Braungart, M., Cradle to Cradle. Remaking the Way We Make Things, North Point Press. New York, 2002.
The Hannover Principles. Design for Sustainability, William McDonough Architects, 1992 [42].
Links
[1] https://www.epa.gov/sites/production/files/2015-09/documents/2012_msw_fs.pdf
[2] https://www.jstor.org/stable/26330534?seq=1
[3] https://www.epa.gov/sustainable-management-food/types-composting-and-understanding-process
[4] https://earth911.com/eco-tech/recycle-solar-panels/
[5] https://news.energysage.com/recycling-solar-panels/
[6] https://www.youtube.com/user/cplai
[7] https://www.youtube.com/embed/HjNv_iTsXn8
[8] http://commons.wikimedia.org/wiki/File:Recycling_in_Curitiba.JPG
[9] https://www.nationalgeographic.com/environment/2018/10/5-recycling-myths-busted-plastic/#close
[10] http://www.popularmechanics.com/science/environment/recycling/4291576
[11] http://en.wikipedia.org/wiki/Zero_waste
[12] http://www.accessscience.com.ezaccess.libraries.psu.edu/content/recycling-technology/757456
[13] https://www.archives.gov/
[14] https://www.youtube.com/user/chemdotinfo
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[16] http://www.flickr.com/photos/mosmancouncil/3361174611/sizes/l/
[17] https://search-proquest-com.ezaccess.libraries.psu.edu/docview/1822385250?pq-origsite=360link
[18] https://www.youtube.com/user/Liquid8Technology
[19] https://www.youtube.com/embed/kzMYEZmEPyE
[20] https://www.youtube.com/user/redemtech001
[21] hhttps://www.youtube.com/embed/qtT2EZ_d3Xk
[22] https://www.seia.org/solar-industry-research-data
[23] https://www.oregon.gov/odot/pages/index.aspx
[24] https://www.flickr.com/photos/oregondot/3049031707/in/photolist-5Dr5Uc-9asxgn-UzXKdo-piAZLv-aS6GAB-TqDQZi-aRqZKk-5FVki8-aD3Tsi-dmSCPy-gNAgd6-5diQVW-d5ogP-akCadg-pwi95i-fMGDzR-4REM1v-aCYkHS-5FZAeU-8nmnGf-5kq3h1-JJDduP-jaTGgf-95Vn6v-cjt8jE-aURJqc-8E9G29-5iQQmg-61AkM8-3jf1La-6Q7FiQ-fxk8dw-o2UJGh-99MMwG-2x6mJ1-5kkLhM-e9ixPb-e7jWAT-89w8ho-3iMkJg-6U6wJL-9ATXSX-aYjKCp-8E9FSj-8yoY5b-75TNoR-cU4Qz9-HkqM2m-97Hfv8-5SwhJK
[25] https://www.youtube.com/c/SolarPowerWorldOnline
[26] https://www.youtube.com/embed/W6PfFPNxn2I
[27] https://www.youtube.com/c/InternationalSolarEnergySocietyISESFreiburg
[28] https://www.youtube.com/embed/uzyAtULvIfI
[29] https://www.mdpi.com/2071-1050/8/7/596
[30] https://solarindustrymag.com/
[31] http://loadingdock.org/redo/Benefits_of_Reuse/body_benefits_of_reuse.html
[32] http://soles4souls.org/
[33] http://www.liftcil.org/programs/reuse.html
[34] http://soles4souls.org
[35] http://blogs.rochester.edu/thegreendandelion/2012/07/strong-innovation-cooling-pack-reuse-program/
[36] https://archive.ellenmacarthurfoundation.org/explore/the-circular-economy-in-detail
[37] https://www.pexels.com/photo/two-brown-trees-1632790/?utm_content=attributionCopyText&utm_medium=referral&utm_source=pexels
[38] https://www.pexels.com/@jplenio
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[41] https://www.youtube.com/embed/7b9R82vrA40
[42] http://www.mcdonough.com/wp-content/uploads/2013/03/Hannover-Principles-1992.pdf