Plastic is an environmentally harmful organic polymer that is present everywhere. The production of plastic material often results in the release of CO2, which exacerbates the Greenhouse effect. Within the last five decades, global plastic consumption rose from 5 to 100 million tons per year.[1] Most of this consumption is completely unnecessary and a waste of valuable resources, such as the 600 billion plastic bags that are being redundantly produced annually. Additionally, there is no integrated solid waste management, meaning that plastic waste is neither collected properly nor disposed of in an appropriate manner to avoid the negative impacts on the environment and public health. A good example of this is that out of the produced 14 million tons of Styrofoam only 1% is recycled every year![2] The massive amount of plastic waste that remains unrecycled partly ends up in the oceans. There, it accumulates through two underwater vortexes. One of these plastic accumulations is as big as central Europe and is called “Great Pacific Garbage Patch.” The main problem with this is that plastic cannot be degraded like natural resources. It is very durable and its decomposition can take up to 1000 years.[3] Plastics can be divided into macro- (> 5 mm in diameter) and microplastics (≤ 5 mm in diameter), each of which require different approaches for applications. Macroplastics can be found in plastic bags, bottles, car materials, etc. Microplastics, on the other hand, are present in various everyday products, like peelings and creams, and find their way into the wastewater treatment plants through bathroom drains, and house and industrial sewage. Research is already underway to develop some new techniques to convert macroplastics into fuels without harming the environment. This offers a very promising approach, as the plastic can serve for the production of resources that are in high demand.[4] As for treating microplastics, iGEM Berlin 2015 is constructing a modular filtering machine which can be applied in wastewater treatment plants to degrade microplastics in biodegradable compounds. You might be asking, why don’t the wastewater treatment plants filter the plastic? They actually do; however, microplastics are generally separated insufficiently, which is why they enter our natural environment. Consequently, they are taken up by many organisms, including the ones, to malnutrition. Also, the uptake of microplastics by organisms causes mechanical injuries, as well as an obstruction of the digestive system. Toxic compounds, such as DEHP, could leach out from microplastics and affect the flora and fauna of rivers and seas. And even more importantly, microplastics can also affect human beings through the food chain. A research group showed back in 2013 that one microplastic particle smaller than 1 mm can be found per 25 cm3 in depths that range from between about 1000 to 5000 meters. This is a very disturbing fact because the microplastis have reached the very deep sea![5]

References:
[1] Converting Waste Plastics Into a Resource
[2] Plastik als Umweltproblem!
http://www.plastic-planet.de/hintergrund_plastikalsproblem.html
[3] How Long Does It Take a Plastic Bottle to Biodegrade?
http://www.postconsumers.com/education/how-long-does-it-take-a-plastic-bottle-to- biodegrade/
[4] Converting Waste Plastic to Ultra-Clean, Ultra-Low Sulphur Fuel
http://www.plastic2oil.com/site/home
[5] Microplastic pollution in deep-sea sediments
http://www.sciencedirect.com/science/article/pii/S0269749113004387