Materials In Today's World

Limits of Recycling


Recycling has a number of advantages. Properly done, it reduces the usage of raw materials, energy usage, air pollution, water pollution, and greenhouse gas emissions. There are, however, a number of limits to the effective implementation of recycling. Recycling can involve energy usage, hazards, labor costs, and practices by individuals and countries, which can hamper the efficient implementation of recycling plans. The biggest limit to recycling is that not all materials can be recycled and so materials can only be recycled a limited number of times due to degradation each time through the process. This degradation is referred to as downcycling.

In addition, recycling poses a number of societal and ethical issues. As highlighted in the e-book, e-waste recycling has led to electronic waste from developed countries being shipped to undeveloped countries for recycling. In many cases, this leads to low wages and terrible conditions for workers involved in the recycling process and the release of toxins which are environmental and health risks for the individuals and their surrounding communities. Please watch the following video (5:26) which summarizes the limits of recycling as discussed in your e-book and this website.

To Watch

Limits to Recycling
Click for transcript of Limits to Recycling.

A common definition is that recycling is a process which allows waste materials to be turned into new products and prevents the waste of potentially useful materials. Recycling reduces the use of fresh materials. It acts to reduce energy usage, reduces air pollution from incineration, reduces water pollution from land filling by reducing the need for conventional waste disposal, and has lower greenhouse gas emissions as compared to fresh material production. So, with all of these benefits you must be wondering if there are any limits to a process that can have such a positive effect on the environment. Limits to recycling are often considered in terms of energy, hazards, costs, and practices by individuals and countries. The biggest limits of recycling however, is that not all materials can be recycled or can only be recycled a number of times before they lose their quality. Some materials once used are always going to have to be dumped as we have no method for making them useful again. What sorts of materials do you think can be recycled? See if you can come up with five. Pause the video and continue when ready.

Commonly, these are the materials that are recycled: glass, paper, metal, plastic, textile, and electronics. How many did you get?

Now let's consider the different limitations. First up is the energy aspect. Put simply some materials like paper and aluminum metal agree to have lower processing costs when it comes to recycling them rather than using fresh materials to make new products. However, the recycling of materials like plastics is extremely energy intensive. Before the plastics can be melted and mixed together, they require sorting usually by hand as there are many different types of plastics usually indicated by special marking a number. If a mixture of plastic recycled together now ever contaminate the melt or you get a lower grade of plastic than the originals which is therefore less valuable. This reduction in the quality of recycling product is called downcycling. In addition to this there is the added complication that devices often use mixed materials. Think of a car. There are wide range of recyclable materials the copper wire the aluminum in engine some of the plastics, the glass, and the iron however, what about the alloys? These are mixtures of metals energy will be needed to separate these and so one of the most difficult problems of recycling is the separation of randomly intermixed particles.

Secondly, there are hazards to recycling including the recycling of dangerous metals. Can you think of any dangerous metals? Pause the video and name some. Continue when you are ready.

Some of the metals associated with recycling are lead and mercury. Often these metals can come from the recycling of waste electrical and electronic equipment. In India and China, a significant amount of pollution is generated where informal recycling in an underground economy of these countries has generated an environmental and health disaster. High levels of lead polybrominated diphenyl ethers, polychlorinated dioxins and furans, as well as polybrominated dioxins, have become concentrated in the air, bottom ash, dust, soil, water, and sediments in areas surrounding these underground recycling sites. Many of these chemicals become dissolved in the water that we drink called leachates. Also, plants can take up these chemicals allowing toxic chemicals to enter the food chain. Finally, if the chemicals are airborne there are own problems with us inhaling them.

There are also social issues connected to recycling whilst it may create jobs they are often jobs with low wages and terrible working conditions in developing countries. In areas without many environmental regulations or worker protections, job like ship braking can result in deplorable conditions for both workers the surrounding communities.

Thirdly, is a challenge for you what do you think the cost of recycling depends on? Pause, think, and continue when ready.

A good answer might be that the costs of recycling depend on the efficiency of the recycling program. Governments or local authorities may not recycle because it's cheaper to use landfill. Also, consumers are encouraged to recycle, but this depends on people being involved in pre-sorting their recycling. Some countries or local governments impose charges when this is not done.

Credit: FuseSchool

In the next section, we will discuss the recycling of polymers, in particular, plastics.