RE-cycling

RE-cycling
Photo by Andrea Begoni
Showing posts with label IPCC. Show all posts
Showing posts with label IPCC. Show all posts

Tuesday, 16 December 2014

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!

Tuesday, 9 December 2014

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!