Biological degradation of plastics: a comprehensive review.

https://scholarlypublications.universiteitleiden.nl/access/item%3A2978611/view

Microplastics in freshwater and terrestrial environments: Evaluating the current understanding to identify the knowledge gaps and future research priorities.

https://bura.brunel.ac.uk/bitstream/2438/18351/1/FullText.pdf

An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling.

Polymers in sensor applications

Each year vast amounts of plastic are produced worldwide. When released to the environment, plastics accumulate, and plastic debris in the world's oceans is of particular environmental concern. More than 60% of all floating debris in the oceans is plastic and amounts are increasing each year. Plastic polymers in the marine environment are exposed to sunlight, oxidants and physical stress, and over time they weather and degrade. The degradation processes and products must be understood to detect and evaluate potential environmental hazards. Some attention has been drawn to additives and persistent organic pollutants that sorb to the plastic surface, but so far the chemicals generated by degradation of the plastic polymers themselves have not been well studied from an environmental perspective. In this paper we review available information about the degradation pathways and chemicals that are formed by degradation of the six plastic types that are most widely used in Europe. We extrapolate that information to likely pathways and possible degradation products under environmental conditions found on the oceans' surface. The potential degradation pathways and products depend on the polymer type. UV-radiation and oxygen are the most important factors that initiate degradation of polymers with a carbon-carbon backbone, leading to chain scission. Smaller polymer fragments formed by chain scission are more susceptible to biodegradation and therefore abiotic degradation is expected to precede biodegradation. When heteroatoms are present in the main chain of a polymer, degradation proceeds by photo-oxidation, hydrolysis, and biodegradation. Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.

/pdf/pathways-for-degradation-of-plastic-polymers-floating-in-the-110uao8lbz.pdf

Pathways for degradation of plastic polymers floating in the marine environment

Algae have recently received growing attention given its prospects as a source of renewable energy and its potential for CO2 capture. Algae culture is of increasing value given that: (i) algae can be cultivated on non-agricultural land using wastewater, (ii) algae can provide a high yield on a per unit of light irradiated area, (iii) algae growth requires CO2 and nutrients that can be obtained from wastewater and fossil fuel combustion and (iv) algae contains high oil and starch making possible the production of high quality biodiesel. Thus, algae culture can contribute to CO2 fixation, wastewater treatment and can be a source of bioenergy. This article presents a critical review, focusing on various microalgae species that consume CO2 and nutrients from wastewater, and provide high quality biofuel. In this respect, a number of relevant topics are discussed in this review: (a) the media for algae culture, (b) the photobioreactor, (c) the associated wastewater treatment processes, (d) the CO2 capture mechanism and (e) microalgal harvesting. This review also considers various aspects of the biomass processing such as (a) lipid extraction, (b) thermodynamics of the produced biomass conversion, (c) biomass gasification, (d) biodiesel production, (e) catalysts, (f) reaction pathways/mechanisms and (g) reaction kinetics.

Integrated CO2 capture, wastewater treatment and biofuel production by microalgae culturing—A review

Carotenoids from microalgae: A review of recent developments.

Microbial degradation and deterioration of polyethylene – A review

With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

Amarjeet S. Bassi

Papers

Integrated CO2 capture, wastewater treatment and biofuel production by microalgae culturing—A review

Carotenoids from microalgae: A review of recent developments.

Microbial degradation and deterioration of polyethylene – A review

A Review of Plastic Waste Biodegradation

Biodesulfurization of refractory organic sulfur compounds in fossil fuels