Learning to respect our everyday garbage

A’liya Spinner

The Plastic Devourer

On a sloping hill overlooking the Malaysian metropolis of Kuala Lumpur sits a sprawling complex like a resting arachnid. Behind its austere walls is a bustling factory, refinery, nursery, and recycling plant, all housed together and working in tandem. People and machines, too, work together inside, managing the tens of thousands of tons of garbage being shipped in from all around the country every day by a steady string of trucks and boats. This month alone, over a million tons of plastic trash has entered the belly of this sedentary behemoth, only to later reemerge reshaped or composted into newborn forms.

Huge solar panels made from recovered and refurbished glass keep the lights on and machines running; even from the streets of Kuala Lumpur, the factory seems to glow through long hours of the night, never sleeping in its constant digestion. At sunrise, employees return and verify its progress, spreading like symbiotes through its twisting veins of corridors and pipes.

Many are tasked with overseeing the most voluminous job at the facility: the reformation of old plastics. By the indiscriminate truckload plastic garbage is carted into its bowels and dumped into a pit that never fully empties. From there, huge conveyor belts move it pound by pound through scanners that sort it onto different tracks. The bulk is polypropylene plastic, which is dropped again into huge vats of heated dissolving agents, allowed to soak and break apart into liquid form. Corporations from around the world commission this plastic soup; each vat is given a different chemical additive to influence desirable properties of the product, cooled, and molded to the necessary specifications. Within three days, this trash once considered unsalvageably contaminated is now clean and reborn, sent out on a new truck bed for delivery. But not all the plastic brought into the devouring beast is meltable polypropylene. Another stream of sorted trash is taken along belts and pneumatic tubing to a network of huge, humid greenhouses. These are the lungs of the facility, full of towering native trees and flowers that provide fresh air and offset the few sources of carbon emission that remain in the factory’s operations. These trees are not the reason the plastic is coming here, however— the soil is. Designated garbage is dropped into the greenhouse and buried in the tilled dirt by gardeners, where it is almost immediately “preyed” upon by hungry microorganisms that have been engineered to feed exclusively on plastic polymers. As they feast, the microbes compost the plastic, breaking it apart into tiny molecules that they digest before excreting nutrients that enrich the soil for the greenhouse plants. This process takes longer than the vats— over the coming weeks, the plastic waste will slowly deteriorate and disappear— and does not produce materials that can be sold as new plastic to consumers, but without the tireless microbes, the facility would be helpless to process some of what comes through its gaping jaws. And hidden deeper in the compound are nurseries growing new colonies of these organisms, some of which have been edited on the genetic level to be faster, hardier, or more symbiotic with the environment. The refinery is constantly innovating, and the next generation of microbes will only increase in productivity. Perhaps soon they will be ready to be introduced to natural ecosystems that have been previously ravaged by plastic pollution.

Every part of the factory operates in seamless harmony. It is one of many resting, recycling giants across the world, each doing its part to reduce the waste that clogs rivers and poisons the Earth. It never sleeps, it never tires, and as long as there is plastic waste to rescue, refine, and reclaim, it will never go hungry.

A “New” Renewable Resource

The Earth has a pollution problem. Carbon dioxide clouds the atmosphere and heats the planet; clean water becomes increasingly rare as oil spills, runoff, and indecomposable garbage cycle through rivers and oceanic currents. Fracking, deforestation, and soil degradation are some of the most direct ways that human activity causes harm to the ecosystem, but there is another, much more common and underappreciated danger: plastic and everyday household garbage.

Plastic, unlike many other forms of a waste, never naturally breaks down and cannot be processed by the environment. Instead, it breaks apart into microscopic fragments that permanently accumulate in the ground, water, and ecosystem, compounding the problem over time. These microplastics are so concentrated in oceanic gyres that the term “Plastisphere” has been coined to describe the unique microbial life cycles that have become tied to marine plastic. These tiny, indigestible, and inorganic pollutants cause illness in humans, animals, and both agricultural and wild plants. Additionally, the industry for creating new plastics— through mining oil, refining materials, and breaking down ethane—  is one of the most polluting and environmentally damaging processes in the world.

Innovations in plastic clean-up are providing hope of new, efficient ways to collect and properly dispose of these compounds from impacted communities. However, the question remains: how can we prevent more plastic from piling up in rivers, forests, and urban junkyards, when single-use and industrial plastic have become such a foundation of our society? One of many solutions may be to change the way we perceive plastic. Although many plastics are recyclable, only 1% of plastic waste undergoes recycling— we treat it as single-use, easily disposable material. But plastic itself has the potential to become its own renewable resource. Companies such as PureCycle— founded by material scientist Dr. John Layman— are making that idea a reality. PureCycle is the leading recycler of polypropylene plastic, a commonly used but difficult to “reprocess” material that’s been known to trap unpleasant odors and contaminants. At the PureCycle facility, however, polypropylene is broken apart into a clean, “virgin” state through a low-energy, solvent-based mechanism. This returns it to a safe and usable state; however, because it is not being produced from raw materials, it lacks some of the variability that makes new plastic such a valuable commodity (able to be stiff, flexible, translucent, etc…) Fortunately with the help of Milliken & Company’s senior polymer scientist

Dr. Scott Trenor, PureCycle has developed chemical additives that allow their recycled polypropylene to take on a wider variety of properties. This makes it more desirable for other companies looking to purchase sustainable plastics, and creates a renewable, “closed loop” system for plastics. Of course, a single PureCycle plant only currently processes around 120 million pounds of plastic in a year (out of the 120 billion pounds produced), and much more, worldwide effort is required. But the factory does represent operating proof that even “contaminated” plastics can be transformed into a malleable, renewable resource.

Another solution may be to change the materials from which plastic is made. Modern plastics are cheap to produce and extremely durable, which makes them ideal for packaging and fabrication. But that durability also prevents them from ever breaking down in landfills or water systems. Researchers at UC Berkeley have created a unique solution to this problem: self-destructing plastics. This plastic comes with microscopic “packets” of plastic-devouring enzymes added during creation that function similarly to the pigment beads used to give plastic products their color. These enzymes are kept safe (and dormant) by monomer shells that naturally degrade under ultraviolet light. However, when the plastic compound is exposed to heat and water, the shells break down more rapidly and the enzymes are free to attach to plastic polymers, breaking them down into simpler, eco-friendly forms over the course of a few weeks. According to the research team, the addition of these enzyme capsules does not hinder the adaptability of commercial plastics, and their integration directly into the molecular makeup makes them much more effective at breaking apart plastic waste than when the same enzymes are added to the surface of preformed plastics. Widespread integration of these enzyme-treated plastics would allow waste to be easily recycled when used— they may even be home-compostable by placing trash in warm water for extended periods of time, reducing the need to collect and sort waste at a special facility.

Other companies are considering simpler methods of switching up materials: moving away from petroleum polymers altogether. In combination with “post-consumer recycling” of traditional plastics, a new sustainability effort is focusing on plant-based materials to generate virgin plastics. Using seaweed, sugarcane, and cornstarch, plastic can be produced from renewable plant matter. Some of these compounds behave exactly like petroleum plastics and are not biodegradable, despite perhaps misleading packaging— but others will decompose into safe compounds under the right conditions. Because of this, plant-based plastics are not a complete solution to pollution, and should only be used concurrently with post-consumer recycling initiatives. Rather, these organic sources allow plastic manufacturers to limit their uses of petroleum and fossil fuels, reducing some of the pollutants associated with the very creation of plastic products at their source.

Thoughtful Implementation

The plastic crisis is an urgent one, and may make both everyday households and eco-conscious corporations eager for a quick solution. As previously mentioned with bioplastics, we must be careful when investing resources into these marketed sustainable solutions. For example, although they are touted as compostable, some biopolymers will only break apart in highly specific, industrially-heated conditions which are not available in many cities. And when mingled with “normal” plastic, these plant-produced materials can actually contaminate the recycling process of unequipped facilities, leading to all plastic waste ending up in the landfill. Mass production of these bioplastics may inevitably be harmful to the sustainability effort by misleading consumers into believing their plastic trash can be thrown out and reclaimed by nature— which is unfortunately not true for the vast majority of plant-derived plastics. Reducing petroleum consumption is a good first step; allowing falsely-branded “eco friendly” bioplastics to clog recycling facilities and landfills is not the solution we want to strive for.

But there are some bioplastics that do decompose, or at the least, require less processing to recycle. These biodegradable plastics can be an important aid in disrupting the “linear” lifespan of plastics, and shift focus to both circular recycling and economic goals. However, these, too, need to be used responsibly. Getting enough “first-generation” biomass— corn, wheat, and sugar grown for the explicit purpose of biodegradable plastic— would require 54% of the world’s yearly corn yield, and 60% of Europe’s freshwater withdrawal to replace all petroleum plastics. Using “second-generation” materials— the parts of the agricultural industry considered inedible and thrown away— has the benefit of both using otherwise discarded biowaste and not needing any new crops, but requires additional processing to turn low value chaff into usable plastic. These refineries may end up costing more in energy expenditure and labor than would otherwise be saved.

Then, of course, there is the issue of the preexisting plastic in our environment. Not only do we need a cyclical system for new plastics, but old plastics cluttering landfills and never breaking down must also be integrated back into our renewable system. Solutions, therefore, cannot only focus on designing eco friendly plastics, but in sustainably recycling those plastics that we have already created. In turn, these recycling processes must not be energetically costly or polluting to operate, and must be made available to even low-income communities and countries that need them the most. 

What might come next?

The strategies thus far discussed are ones that have already been lightly implemented, or are at least proven effective. No plastic recycling or bioplastic initiative has truly moved beyond infancy, but as climate and environment consciousness increases, so too will our reliance on this strategy of circular manufacturing. As this shift from petroleum polymers and single-use plastic unfolds in the future, what new technologies might arise that we have not yet implemented? In the field of bioplastics, genetic engineering may be a solution to problems of usability or production cost. Many plastics containing beads of plastic-eating enzymes have limited shelf-lives, or require regulated temperature and moisture conditions to avoid “activating” too soon, making them less commercially viable. These enzymes, however, have the proven potential to be engineered to be less sensitive to fluctuations. Not only that, but fungi enzymes,

waxworm bacteria, and soil microbes have all demonstrated varying modes and methods of decomposing plastic waste. Diversifying the enzymes employed in conjunction with a plastic product’s anticipated use, climate, and lifespan may allow companies to “tailor” their biodegradable plastics to be as efficient as possible.

Many engineered microbes have been experimented on for purposes beyond laying dormant in plastic, as well. Some are already employed decomposing thousands of small “pellets” of plastic in France; however, these pellets must be shaped through heating and freezing to be digestible by the organisms, which is time-consuming and requires lots of energy expenditure. In the future, such microbes might be programmed to be even more self-sufficient and plastic-reliant, and will not require their food be pre-processed. Someday they may even be independent and prolific enough to mix with the soil of landfills, where they can break down existing heaps of plastic while adding nutrient-rich byproducts back into the ground.

Nearly all futuristic solutions discussed by researchers and dreamers alike employ the help of nature itself in recycling and reinventing plastic. Alongside the more immediately obtainable steps— streamlining refineries such as PureCycle’s to run on clean solar or wind energy, continuing to curb the contamination of plastics in the water systems, and reducing our daily consumption— the bioengineering of microbes, bioplastic source plants, and the plastics themselves may be a crucial step in new age recycling. Even as we degrade nature, it is nature itself that may yet be the key to correcting our past mistakes and cooperating for a cleaner future.