Author Archives: Michelle Rose Rubio

About Michelle Rose Rubio

Michelle Rose Rubio holds a Masters degree in Environmental Engineering from the University of the Philippines. She also has a Bachelors degree in Chemical Engineering and has worked on several research projects involving wastewater treatment. As a former freelance writer, she has written numerous reports on various topics related to science and engineering. Previously a university instructor on Mathematics and Chemistry, she is now a full-time environmental volunteer based in Qatar and an advocate of environmental sustainability.

Everything You Need to Know About PVC Recycling

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PVC is one of the most widely used plastics worldwide. A major problem in the recycling of PVC is the high chlorine content in raw PVC and high levels of hazardous additives added to the polymer to achieve the desired material quality. As a result, PVC requires separation from other plastics before recycling. PVC products have an average lifetime of 30 years, with some reaching 50 or more years.  This means that more PVC products are reaching the end-of-life and entering the waste stream, and the amount is likely to increase significantly in the near future.

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PVC Recycling Methods

Currently, PVC plastic is being recycled by either of the two ways:

  • Mechanical recycling – This involves mechanically treating the waste (e.g. grinding) to reduce it into smaller particles.  The resulting granules, called recyclate, can be melted and remolded into different products, usually the same product from which it came.
  • Feedstock recycling – Chemical processes such as pyrolysis, hydrolysis and heating are used to convert the waste into its chemical components.  The resulting products – sodium chloride, calcium chloride, hydrocarbon products and heavy metals to name a few – are used to produce new PVC, as feed for other manufacturing processes or as fuel for energy recovery.

In mechanical recycling, because no chemical reaction is involved, the recyclate retains its original composition. This poses a recycling challenge because PVC products, depending on their application, contain different additives.  For example, rigid PVC is unplasticized whereas flexible PVC is added plasticizers because this additive increases the plastic’s fluidity and thus, its flexibility. Even products used for the same application may still differ in composition if they have different manufacturers.

When different kinds of PVC waste are fed to a mechanical recycler, the resulting product’s composition is difficult to predict, which is problematic because most PVC products, even recycled ones, require a specific PVC content.  In order to produce a high-quality recylate, the feed ideally should not be mixed with other kinds of plastic and should have a uniform material composition.Material recycling is therefore more applicable for post-industrial waste than for post-consumer waste.

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Feedstock recycling is seen to be complementary to conventional mechanical recycling as it is able to treat mixed or unsorted PVC waste and recover valuable materials.  However, a study showed that feedstock recycling (or at least the two that was considered) incurred higher costs than landfilling, primarily due to the low value of the recovered products. This provides little incentive for recyclers to pursue PVC recycling.  This may change in the future as more stringent regulations to protect the environment are enacted.  Some countries in Europe have already banned PVCs from landfills and PlasticsEurope is targeting a “zero plastic to landfill” in Europe by 2020.

Post-industrial waste is relatively pure and comes from PVC production and installation, such as cut-offs from laying of cables or scraps from the installation of window frames.  These are easily recycled since they can be collected directly from processors or installers or even recycled by producers themselves as raw material to manufacture the same product.

Post-consumer waste contains mixed material and has been used for different applications.  These are products that have reached the end-of-life or are replaced due to damage, like pipes from underground, window frames being replaced for renovation and electric cables recovered from demolition. These would require further sorting and cleaning, adding cost to the recycling process.  The recyclate produced is usually of lower quality and consequently of decreased economic value.

Recent Developments

Europe is leading the way for a more sustainable use of PVC with programs, such as RecoVinyl and VinylPlus, where recycling is advanced as one of the ways to use resources more efficiently and to divert as much waste as possible from landfills. Recovinyl, created in 2003, is an initiative of the European PVC industry to advance the sustainable development of the PVC industry by improving production processes, minimise emissions, develop recycling technology and boost the collection and recycling of waste.

Having been successful in all of its goals, including an increase in recycling of PVC across Europe to over 240,000 tonnes a year, in 2011 the PVC industry redefined the role of Recovinyl as part of the ambitious new ten-year VinylPlus sustainable development programme. VinylPlus works in partnership with consumers, businesses, municipalities, waste management companies, recyclers and converter, as well as the European Commission and national and local governments. The goal is to certify those companies who recycle PVC waste and those accredited converting companies who purchase recyclate to manufacture new products and applications.

Even if some types of PVC recycling are not feasible or economically viable at present, it will likely be reversed in the future as governments, manufacturers, consumers and other stakeholders create programs that innovate and find ways to achieve a sustainable future for the PVC industry.

Composting in Qatar: An Overview

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Composting in Qatar is mainly done at the Domestic Solid Waste Management Centre (DSWMC) in Mesaieed, which houses the largest composting facility in the country and one of the largest in the world.  The waste that enters the plant initially goes through anaerobic digestion, which produces biogas that can power the facility’s gas engine and generators, followed by aerobic treatment which yields the final product.

Two types of compost are generated: Grade A (compost that comes from green waste, such as yard/park trimmings, leftovers from kitchen or catering services, and wastes from markets) and Grade B (compost produced from MSW).  The plant started its operation in 2011 and when run at full capacity is able to process 750 tons of waste and produce 52 tons of Grade A compost, 377 tons of Grade B compost, liquid fertilizer which is composed of 51 tons of Grade A compost and 204 tons of Grade B compost, and 129 tons of biogas.

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This is a significant and commendable development in Qatar’s implementation of its solid waste management plan, which is to reduce, reuse, recycle and recover from waste, and to avoid disposing in landfills as much as possible.  However, the large influx of workers to Qatar in the coming years as the country prepares to host the World Cup in 2022 is expected to substantially increase solid waste generation and apart from its investments in facilities like the composting plant and in DSWMC in general, the government may have to tap into the efforts of organizations and communities to implement its waste management strategy.

Future Outlook

Thankfully, several organizations recognize the importance of composting in waste management and are raising awareness on its benefits.  Qatar Green Building Council (QGBC) has been actively promoting composting through its Solid Waste Interest Group.  Last year, they were one of the implementers of the Baytna project, the first Passivhaus experiment in the country.

This project entails the construction of an energy-efficient villa and a comparative study will be performed as to how the carbon footprint of this structure would compare to a conventional villa.  The occupants of the Passivhaus villa will also be made to implement a sustainable waste management system which includes composting of food waste and garden waste, which is meant to lower greenhouse gas emissions compared to landfilling.

Qatar Foundation is also currently developing an integrated waste management system for the entire Education City and the Food Services group is pushing for composting to be included as a method to treat food and other organic waste.  And many may not know this but composting can be and has been done by individuals in their own backyard and can even be done indoors with the right equipment.

Katrin Scholz-Barth, previous president of SustainableQatar, a volunteer-based organization that fosters sustainable culture through awareness, skills and knowledge, is an advocate of composting and has some great resources on how to start and maintain your own composting bin as she has been doing it herself.

A simple internet search will also reveal that producing compost at home is a relatively simple process that can be achieved with minimal tools.  At present, very few families in Qatar are producing their own compost and Scholz-Barth believes there is much room for improvement.

As part of its solid waste management plan as stated in the National Development Strategy for 2011-2016, Qatar aims to maintain domestic waste generation at 1.6 kg per capita per day.  This will probably involve encouraging greater recycling and reuse efforts and the reduction of waste from its source.

It would also be worthwhile to include programs that will promote and boost composting efforts among institutions, organizations and individuals, encouraging them with the fact that apart from its capability of significant waste diversion from landfills, composting can also be an attractive source of income.

Note: The article is being republished with the permission of our collaborative partner EcoMENA. The original article can be viewed at this link.

Recycling of EPS Foam Packaging

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Municipalities and organisations around the world are facing a growing problem in disposal and recycling of EPS foam packaging and products. EPS foam (Encapsulated Poly-Styrene) packaging is a highly popular plastic packaging material which finds wide application in packaging of food items, electronic goods, electrical appliances, furniture etc due to its excellent insulating and protective properties. EPS foam (also known as polystyrene) is also used to make useful products such as disposable cups, trays, cutlery, cartons, cases etc. However, being large and bulky, polystyrene take up significant space in rubbish bins which means that bins becomes full more quickly and therefore needs to be emptied more often.

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Polystyrene is lightweight compared to its volume so it occupies lots of precious landfill space and can be blown around and cause a nuisance in the surrounding areas. Although some companies have a recycling policy, most of the polystyrene still find its way into landfill sites around the world.

Environmental Hazards of EPS Foam

While it is estimated that EPS foam products accounts for less than 1% of the total weight of landfill materials, the fraction of landfill space it takes up is much higher considering that it is very lightweight.  Furthermore, it is essentially non-biodegradable, taking hundreds perhaps thousands of years to decompose.

Even when already disposed of in landfills, polystyrene can easily be carried by the wind and litter the streets or end up polluting water bodies. When EPS foam breaks apart, the small polystyrene components can be eaten by marine organisms which can cause choking or intestinal blockage.

Polystyrene can also be consumed by fishes once it breaks down in the ocean.  Marine animals higher up the food chain could eat the fishes that have consumed EPS, thus concentrating the contaminant.  It could be a potential health hazard for us humans who are on top of the food chain considering that styrene, the plastic monomer used in manufacturing EPS has been classified by the US National Institutes of Health (NIH) and the International Agency for Research on Cancer (IARC) as a possible human carcinogen.

Styrene is derived from either petroleum or natural gas, both of which are non-renewable and are rapidly being depleted, creating environmental sustainability problems for EPS.

Trends in EPS Foam Recycling

Although the Alliance of Foam Packaging Recyclers have reported that the recycling rate for post-consumer and post-commercial EPS in the United States have risen to 28% in 2010 from around 20% in 2008, this value is still lower than most solid wastes.  According to USEPA, auto batteries, steel cans and glass containers have recycle rates of 96.2%, 70.6% and 34.2% respectively.

Because it is bulky, EPS foam takes up storage space and costs more to transport and yet yields only a small amount of polystyrene for re-use or remolding (infact, polystyrene accounts for only 2% of the volume of uncompacted EPS foams). This provides little incentive for recyclers to consider EPS recycling.

Products that have been used to hold or store food should be thoroughly cleaned for hygienic reasons, thus compounding the costs.  For the same reasons, these products cannot be recycled to produce the same food containers but rather are used for non-food plastic products.  The manufacture of food containers, therefore, always requires new polystyrene.  At present, it is more economical to produce new EPS foam products than to recycle it, and manufacturers would rather have the higher quality of fresh polystyrene over the recycled one.

The cost of transporting bulky polystyrene waste discourages recyclers from recycling it.  Organizations that receive a large amount of EPS foam (especially in packaging) can invest in a compactor that will reduce the volume of the products. Recyclers will pay more for the compacted product so the investment can be recovered relatively easier.

There are also breakthroughs in studies concerning EPS recycling although most of these are still in the research or pilot stage.  Several studies have found that the bacteria Pseudomonas putida is able to convert polystyrene to a more biodegradable plastic.  The process of polystyrene depolymerization – converting polystyrene back to its styrene monomer – is also gaining ground.