"Recycling: yes or not?"

Hi bloggers!

After a while, it is now time to complete the “Recycling: yes or not?” discussion. That will roughly take two more posts, I promise.

The conclusion of the last post introduces what I am going to talk about today: in the next paragraphs, I will analyze the remaining disposal methods. In order to do that, these posts will be mainly based on the “Environmental benefits of recycling – update 2010“ report, edited by the Waste & Resource Action Program (WRAP – www.wrap.org.uk). This document runs a clear excursus across all the waste treatment methods, highlighting the best disposal solution for every different type of waste. Moreover, it is focused on the Municipal Solid Waste and, obviously, it analyzes also landfilling and incineration. Considering that these two disposal options have been already discussed, I will be mostly talking about Composting, Anaerobic Digestion and Pyrolysis in comparison to recycling.

Before analyzing in detail the contents of this report, I would like to get started with a significant sentences available in the summary (page 1):

“The conclusion was clear – most studies show that recycling offers more environmental benefits and lower environmental impacts than the other waste management options”.

Right, the scheme followed by the report is structured according to the different type of waste. For the first one, cardboard, it is shown that landfilling, incineration and recycling are the most common treatment. Same consideration can be found in other works like Arena et al. (2004). As well as WRAP report, the authors actually note that for paper, incineration could be sometimes better that recycling because it allows higher ratios in terms of energy recovery. Considering instead both the water usage (quite high for incineration) and energy request, recycling seems to be the best option. In 2014, Bajpai totally promoted paper recycling instead: indeed, his work points out how paper produced from recycled material requires less energy, prevent virgin material employment and reduce environmental pollution (Bajpai 2004). 

Same conclusions have been traced by a Swedish study. Herein, the authors show how "the potential saving that can be made when going from incineration to recycling is 1.2 million ton CO2 -equivalents" (Finnveden et al. 2005: 225).

Concerning plastics, recycling is overall ranked as the best option in terms of climate change (low impact), energy demand as well as water request (low as for paper). Pyrolysis is also considered as a preferred disposal methods because it is the treatment that shows the lowest toxics effects on human health.

Also Quian et al. (2014) promoted the pyrolysis process: considering before the advantages of recycling, as it helps to protect the environment and reduce the use of natural resources, they illustrated that, with its considerable heating value (Kiran et al. 2000), plastic represents the right ingredient to produce a more calorific fuel.

The problem of recycling plastic consists in its costs: how explained by Eriksson et al. (2005), recycling plastics presents the lowest consequences but, at the same time, the highest outlay. However, the same study explains how the general term “recycling” means reducing the environmental impact as well as softening the demand of energy resources and also limiting the economic expenses.

Anaerobic digestion (AD) and composting are taken into account especially when food and organic waste are involved but this, with few more important bits, will be the topic of the last "Recycling: yes or not" post.

See you soon on RE-cycling!

Recycling: yes or not?

Incineration

Back again on RE-cycling!
Let's restart the debate that I started few posts ago. Today it is time to talk about the incinerations’ impact.

Incineration consequences are involved in two main fields: global warming and human health. In both cases, the original factor that needs an accurate analysis is the gas emissions. Despite the combustion of waste does not release methane, in terms of global warming incineration is problematic because of the amount of CO2, N2O and NH3 emitted ("Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories" IPCC 2000, page 455). Instead, considering humankind health, Daskalopoulos et al. (1997) explain how municipal waste combustion released "polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF)" (Daskalopoulos et al. 1997: 226). These are generally known as toxins and they are considered causes of skin and liver diseases as well as cancer. Moreover, the same authors say that also metal compounds, heavy metals and acids gases are a result of waste incineration and also involved in the human health concerns.

However, comparing incineration to landfilling, it is easily noticeable that:
1. gaining and using energy from incineration is easier rather that from landfilling. Indeed, as highlighted in “Incineration of Municipal Solid Waste” report (DEFRA 2013), from incineration there is a substantial gain of usable energy in terms of heat and electricity.
Even though successful attempts have been done, energy recovery from landfilling is in fact a quite expensive procedure and it is mainly discussed as a possibility rather than a convenient and actual opportunity (Lombardi et al. 2006).
2. intuitively, incineration reduces the volume of waste. This means that less rubbish is thus dispatched to the land. Moreover, the residual bottom ash can also be reused in other engineering fields like road building (Incineration of Municipal Solid Waste, DEFRA 2013).
3. as explained in the UK Government report “Waste GHG Inventory Summary Factsheet”, the emissions from landfill represent the biggest amount of Green House Gases concerning the waste management (incineration does not produce CH4). In 2010, 89% of UK waste disposal gases came from land and just a minor part from incineration.
4. finally, another evidence is that water and soil pollution are mainly related to the leachate derived from the landfilled waste. Water contamination coming from incineration is minimal (Daskalopoulos et al. 1997).

Keeping in mind the energy recovery concept, I would say that with this post we have learnt why landfilling is at the bottom of the “Waste Hierarchy” and why the incineration is located in a slightly better position.
At this stage, we have to keep climbing the hierarchy as well as keep comparing the different disposal method each other. In the next few posts I should be able to conclude the current discussion and hopefully I will have fully explained the RE-RE-RE importance.

So...see you soon on RE-cycling!

Recycling@UCL

Green UCL

Hi everyone!
I am writing a new post because this morning I received an important email so, before carrying on with the most important discussion of this blog (“Recycling: yes or not?”), I decided to talk about the “Green UCL”. The subject of the email that I got is “Are you ready for the Christmas Switch Off?” and it clearly sounded like something to talk about.

Together with the “Green Champions” and the “Environmental Sustainability Team”, “Green UCL” works in order to create a more sustainable university, striving for a more and more green, clean and healthy world. Green UCL organizes frequent events and activities aimed to promote and make aware students (and people) about the sustainable issue.
The most important activity planned for December 2014 is exactly the “Christmas Switch Off” (figure 1), organized to save energy, hence carbon and money, during the Christmas holidays.



Figure 1: "The Christmas Switch Off" poster

The idea arises considering that, during the near winter break, lots of machines and devices will be left on. Therefore, the “Christmas Switch Off” represents an intuitive, simple but important tip aimed to prevent an unnecessary waste of energy. The same event was organized during the last Eastern Holidays and the result was awesome: the saved-energy would have been enough to make 2 million cups of tea! If you need a list with all the things that could and should be switched off have a look at the "checklist and resources" link.
There is also a sort of contest that runs together with the switch off event: anyone is invited to send photos while switching off lights, radiators, projectors or whatever and, for the most original one, there is a book voucher or a chocolate award.

Obviously, Green UCL also cares about the recycling within the university. On December 4th, for instance, the facebook page was updated with a post related to new UCL recycling signage and its meaning (figure 2).

  

Figure 2: facebook screenshot of Green UCL page

To get involved with Green UCL follow this link.
Twitter: @GreenUCL – facebook: facebook.com/greenucl

So, the next post will restart the “Recycling: yes or not?” discussion. Stay tuned to read about the incineration process and its links with the other disposal methods.

See you soon on RE-cycling!

Recycling: yes or not?

Landfilling

Hi everyone!

I hope that this idea to split the discussion in several and focused posts is useful. Therefore, avoiding long introductions, today it is time to talk about landfilling consequences.

Landfilling waste produces a considerable amount of gases, of which Methane and Carbon Dioxide are the most common. The thing is that CH4 and CO2 belong to the GHGs group (Greenhouse Gases) so, their production is strictly connected to the global warming issue (2014 IPCC's "Synthesis Report", page 4, 43 and 116 and 2014 DEFRA report "Energy from Waste", paragraph 37).

A work conducted by Daskalopoulos et al. (1997) shows concrete data about the amount of Methane and Carbon Dioxide in UK due to waste landfilling: the former is the 63.8% of the total volume while the latter is the 33.6%. Thereafter, besides global warming, the most relevant problems linked to landfilling are intuitively detailed by the authors as water pollution, risk of explosion (due to gas accumulation) and health problems (Daskalopoulos et al. 1997: 214 and 215). The same bad consequences can be found in other papers: El-Fadel et al. (1997) actually include also air pollution and vegetation damage.

In addition to the gases, both these papers talk about the leachate, which is the liquid result of the waste degradation. Leachate does not have a big influence in terms of global warming as much as gas does, but it is widely taken into account when it is related to water and soil pollution.
Again, the same list is highlighted in a really interesting report edited by DEFRA in 2011: "Applying the Waste Hierarchy: evidence summary" describes, for each different kind of waste (paper, aluminium, plastic and so on), what the favourite disposal methods are: landfilling is again the last favoured option and the reason is because of the high health, environment and climate change impacts that it brings.
Finally, there is one more aspect to account for: land availability. We have to consider that also the waste production is consequently growing together with the population. Therefore the landfill sites are getting full and there is an actual need to find new places to install new sites and new rubbish. A study conducted by King et al. (2006) tackles this issues and shows how the available land space is predicted to finish. Moreover, the three researchers lead their work explaining how, also in the land availability context, the general concept of recycling is the key tool to treat waste in the next future.

After this brief summary about landfill implications, I have to keep following up the “Waste Hierarchy”: as explained in the previous post, I want to reach to top of the triangle starting from its base. The next step is thus related to incineration, which will be the topic of the next post.

See you soon on RE-cycling!

Recycling: yes or not?

An introductive chat

It has been a while since I’ve post a new piece of writing so today I want to keep talking about the issues I left in ice at the end of “Digging the Topic – part 3”. Basically, I want to understand whether or not the recycling process is important and, if yes, why. I am aware that the answers can be easily taken for granted, but the aim is to tackle this topic with a scientific approach. Then, considering that it will be probably a long discussion, I am going to split it in different posts. "Recycling: yes or not?" will be the title of every post while the subheading will address every single post.

I believe that the right starting point consists in talking about the disposal method that do not include energy recovery. Why? Because landfilling and incineration are widely evaluated as the worst existing waste disposal options and, at the same time, they represent the most widespread waste treatment. Figure 1, taken from the 2011 EU’s publication "Generation and treatment of municipal solid waste", refers to the European situation and it schematically shows how much common landfilling and incineration are when compared to all the other main waste disposal. Indeed, in 2009, these two treatments were used to treat more than half of the total amount of European waste (278 on a total of 492 kg for each inhabitant).

 Figure 1: schematic waste treatments usage according to the EU's website

(y=kg procapita; x=years). Click to enlarge.

Surely, the image shows also how that landfilling operations decreased between 1995 and 2012 as well as recycling increased but, according the Directive 2008/98/EC of the European Parliament and of the Council, this positive trend must be only a starting point. As I mentioned in the previous post called “2020 is getting closer and closer” the European Community advised both that landfilling must be further reduced and that, by 2020, the recycling ratio needs to reach the 50% in weight (nowadays England is at 43%).

Giving this discussion a worldwide perspective, a huge challenge is for the developing countries. An example comes from an interesting work about the waste typology and disposal methods in 6 Asian country. Indris et al. (2004) explain how important is the waste debate in those countries where the amount of rubbish is prominently growing together with the population. Ignoring the discussion about the different kind of waste, the authors show striking data like China’s landfilling percentage, which reached 96% in 2011. In other countries, like Taiwan and Malaysia, is also highlighted how landfilling and incineration are the most common used methods for getting rid of most of the rubbish. Summarizing, this paper is highly useful because it tells us the importance of gaining a wider knowledge about waste disposal in those countries where the amount of waste is getting higher and higher. The concern is aimed to prevent environmental and health issue that frequently arise from a bad waste management know-how.

I think that this sounds as a good introduction post to the following discussion. My aim consists in exploring the advantages of the recycling by understanding first all the concerns and limitations related to the other disposal methods. I will start thus from the bottom of the “Waste Hierarchy” (click here to refresh your mind about it) and, through the less favourite disposal methods, I will hopefully show why the “RE-RE-RE” are located at the top of the triangle. Hence, the next posts will be dealing with few considerations about landfilling and incineration.

See you soon on RE-cycling!