Plastic waste is an issue of global concern because of the environmental impact of its accumulation in waste management systems and ecosystems. Biodegradability was proposed as a solution to overcome this problem; however, most biodegradable plastics were designed to degrade under aerobic conditions, ideally fulfilled in a composting plant. These new plastics could arrive to anaerobic environments, purposely or frequently, because of their mismanagement at the end of their useful life. This review analyzes the behavior of biodegradable and conventional plastics under anaerobic conditions, specifically in anaerobic digestion systems and landfills. A review was performed in order to identify: (a) the environmental conditions found in anaerobic digestion processes and landfills, as well as the mechanisms for degradation in those environments; (b) the experimental methods used for the assessment of biodegradation in anaerobic conditions; and (c) the extent of the biodegradation process for different plastics. Results show a remarkable variability of the biodegradation rate depending on the type of plastic and experimental conditions, with clearly better performance in anaerobic digestion systems, where temperature, water content, and inoculum are strictly controlled. The majority of the studied plastics showed that thermophilic conditions increase degradation. It should not be assumed that plastics designed to be degraded aerobically will biodegrade under anaerobic conditions, and an exact match must be done between the specific plastics and the end of life options that they will face.

https://www.mdpi.com/2073-4360/12/1/109/pdf

Degradation of Plastics under Anaerobic Conditions: A Short Review.

The high costs involved in treating wastewater are problems that developing countries confront, mainly in rural areas. Therefore, Constructed Wetlands (CWs), which are composed of substrate, vegetation, and microorganisms, are an economically and ecologically viable option for wastewater treatment in these places. There is a wide variety of possibilities for substrates and ornamental plants that have not yet been evaluated to be implemented in future CW designs. The goal of this study was to evaluate the process of adaptation and removal of wastewater pollutants in CW microcosms using different terrestrial ornamental plants (Lavandula sp., Spathiphyllum wallisii, and Zantedeschia aethiopica). Those plants were sown in two types of substrate: red volcanic gravel (RVG) and polyethylene terephthalate (PET). CWs with vegetation reduced 5-day biochemical oxygen demand (BOD5) by 68% with RVG substrate and 63% with PET substrate, nitrates 50% in RVG substrate and 35% in PET substrate, phosphates 38% in RVG substrate and 35% in PET substrate, and fecal coliforms 64% in RVG and 59% in PET substrate). In control microcosms without vegetation, reductions were significantly lower than those in the presence of plants, with reduction of BOD5 by 61% in RVG substrate and 55% in PET substrate, nitrates 26% in RVG substrate and 22% in PET substrate, phosphates 27% in RVG substrate and 25% in PET substrate. Concerning fecal coliforms 62% were removed in RVG substrate and 59% in PET substrate. Regarding the production of flowers, Lavandula sp. did not manage to adapt and died 45 days after sowing and did not produce flowers. Spathiphyllum wallisii produced 12 flowers in RVG and nine flowers in PET, while Zantedeschia aethiopica produced 10 in RVG and 7 in PET. These results showed that the use of substrates made of RVG and PET is a viable alternative to be implemented in CWs. In addition, the reuse of PET is an option that decreases pollution by garbage. The plants Spathiphyllum wallisii and Zantedeschia aethiopica remarkably contribute in the removal of pollutants in wastewater. Additionally, the use of ornamental plants, with commercial interest such as those evaluated, enables an added value to the CW to be given, which can be used for flower production purposes on a larger scale and favor its acceptance within rural communities.

https://www.mdpi.com/2071-1050/10/5/1594/pdf

Effects of the Use of Ornamental Plants and Different Substrates in the Removal of Wastewater Pollutants through Microcosms of Constructed Wetlands

Addressing tensions in coopetition for sustainable innovation : insights from the automotive industry

Making current chemistry practice sustainable is a relatively new issue in developing countries. The current curricula for chemists' and engineers' education barely consider environmental sustainability as its own component. This make it difficult to train human resources to have consciousness about the implications of synthetizing chemicals with multiple applications while also considering the life cycle of the chemical and its final fate in the environment. For example, during the last Latin American Federation of Chemical Associations meeting in 2016, not a single paper was devoted to sustainable chemistry issues. This paucity is a clear demonstration that educational curricula must progress to include sustainability in order to raise the concern of a new generation of professionals. This issue is also linked to sustainable development goals (SDGs) and that of sustainable production and consumption. One element that may help raise concern of sustainable chemistry may be concentrated in problems that raise public interest, one being plastic pollution initially raised as a marine litter issue, but which is a far more complex problem, since plastic polymers contain a great variety of chemicals that complicate recycling and final disposal, but which brings the opportunity to address the issue of chemicals in the environment through some upstream solutions (i.e., before the plastics can become an environmental concern). Without doubt, we need strong education in chemical synthesis and green chemistry principles to address molecular design and minimize impacts ab initio, in addition to a pursuit of material innovation. It is also necessary to think of customers’ needs, where chemistry meets economy and social sciences, and which can barely be observed in current chemistry and engineering curricula in developing countries. Possible solutions might be generated from an interdisciplinary, problem-oriented perspective.

Sustainable chemistry challenges from a developing country perspective: Education, plastic pollution, and beyond

https://dialnet.unirioja.es/descarga/articulo/6276484.pdf

La cultura organizacional y su influencia en la sustentabilidad empresarial. La importancia de la cultura en la sustentabilidad empresarial

Waste management and environmental impact of absorbent hygiene products: A review:

As part of the actions that the Universidad Autonoma Metropolitana, campus Azcapotzalco, has developed in order to promote sustainability, in October 2003 began the waste management program “Separaccion por un mejor UAMbiente”. This paper explains the methodology used to built the program, the results of the first stage (recovery of recyclable waste in open areas) and the start of the second stage, which is focussed in segregation of recyclables in offices. Until now 7099 kg of PET bottles, 12 829 kg of multilayer packaging, 171 kg of aluminium cans, 10 487 kg of glass, 26 361 kg of paper and 20 500 kg of cardboard, for a total of 77 447 kg of waste, have been recovered and sent to recycling.

/pdf/la-gestion-ambiental-en-una-institucion-de-educacion-24t7xfw5n5.pdf

La gestión ambiental en una institución de educación superior asociada a las prácticas de separación y recuperación de residuos

Los plasticos son una de las corrientes de residuos que ha despertado mayor interes en los ultimos anos, debido a su continuo crecimiento y a sus efectos ambientales, que incluyen la saturacion de sitios de disposicion final y afectaciones en los ecosistemas, a los que llegan debido a un manejo inadecuado. En esta investigacion se analizan y comparan la generacion de residuos plasticos no industriales, las medidas legislativas abocadas a la minimizacion de sus impactos y las tendencias de valorizacion. La generacion de residuos plasticos oscila entre el 9 y el 14 % de la masa de residuos solidos urbanos, con una tendencia a aumentar en forma directa con el producto interno bruto de los paises y en las grandes zonas metropolitanas. Con el fin de dar un manejo integral a estos residuos los paises han adoptado medidas que incluyen legislaciones especificas, normas, sistemas de acopio y de informacion. Un caso relevante, por sus connotaciones ambientales, es el de las bolsas de plastico; las medidas adoptadas a este respecto incluyen su prohibicion o la sustitucion por bolsas biodegradables. En cuanto a la valorizacion, se detecta un incremento en el reciclaje, a traves del acopio formal e informal. Las medidas establecidas, especialmente en America Latina, han tenido un impacto aun limitado, debido principalmente a la falta de articulacion entre las mismas, la produccion de plasticos y el sistema de gestion de residuos.

/pdf/generacion-legislacion-y-valorizacion-de-residuos-plasticos-18xkh0tcdc.pdf

Generación, legislación y valorización de residuos plásticos en iberoamérica

The changes in the regulations regarding solid waste management in Mexico City during 2009 and 2010 promoted the use of oxo-biodegradable plastic bags. These kind of materials can be biodegraded after oxidation by temperature, UV radiation, friction or a combination of them. The standard ASTM method (5338) to asses biodegradability of plastics requires the use of mature compost, in closed reactors with a constant flow of air and a temperature of 58 oC. This work assessed the feasibility of testing degradability of oxo-biodegradable plastic films in a controlled composted process, which uses organic waste and local environmental conditions. The system, built in 200 L reactors, showed the feasibility to compost oxo-biodegradable plastics. After 45 days the films showed degradation, assessed by fragmentation, a decrease in elongation at breaking

/pdf/propuesta-metodologica-para-la-evaluacion-de-la-3zwy8y14jn.pdf

Rosa María Espinosa Valdemar

Papers

Waste management and environmental impact of absorbent hygiene products: A review:

La gestión ambiental en una institución de educación superior asociada a las prácticas de separación y recuperación de residuos

Generación, legislación y valorización de residuos plásticos en iberoamérica

Propuesta metodológica para la evaluación de la degradabilidad de plásticos mediante composteo