The degradation and toxicity of commercially traded vegetable oils following spills in aquatic environment.

The production of commodity and specialty vegetable oils is increasing every year to fulfill the ever-increasing demand where the trading of oils occurs primarily via sea shipping. Spills of vegetable oil into the aquatic environment may result in detrimental effects on aquatic ecosystems. Environmental degradation of vegetable oil spills occurs mainly via microbial activity, chemical oxidation, wave and wind actions. However, the polymerization of oils can hinder their ability to naturally degrade. Thus, human intervention in the form of both short- and long-term remediation, is desirable to reduce the effects of vegetable oil spills on aquatic ecosystems. Studies have been conducted to determine how the type and concentration of the vegetable oil contamination influence its toxicity on various organisms. Some studies show that the effect of vegetable oil spills is found to be relatively short-lived and to a certain extent increase the survivability of certain organisms. However, the integrated effect of vegetable oil spills on aquatic organisms and their environment is still being researched. This review summarizes the existing knowledge on the reported occurrences of vegetable oil spills, their degradation, and their toxicity towards the surrounding aquatic environment which would be helpful in the knowledge transfer of remediation of vegetable oils.

The nexus between biofuels and pesticides in agroforestry: Pathways toward United Nations sustainable development goals.

The growth of global population continuously increases the demands for agroforestry-derived products, underpinning a sustainable growth of energy matrix in the sectors of food security, transportation, and industrial is momentous. The high demand for the sustainable energy sources has led to an increase in the application of pesticides associated with growing crops for the production of biofuel. In 2019, the global consumption of pesticides was 4.2 million tonnes. Case studies on life cycle assessment (LCA) of pesticides showed that toxicity is the major severe impact of pesticide usage, contributing to human toxicity (∼70%) and freshwater eco-toxicity (>50%). This alarming situation needs a solution as conventional pesticides pose various negative impacts to human and the environment, rendering the biofuel production process unsustainable. In this review, we focus on the interaction between pesticide use, biofuel production, food security for a sustainable balancing in between government benefits, environmental, and human health, aiming to track the implications and impact to the global efforts towards achieving the UN Sustainable Development Goals (SDGs). Even though, there are strict government regulations and legislations pertaining to pesticide use, and policies devised as guidelines for agroforestry sectors to implement and monitor these measures, the discrepancies still exist in between national and supranational entities. To cater the above issue, many efforts have been made to upscale the biofuel production, for example, the United States, Brazil, China and Indonesia have ventured into biofuels production from non-food-crops based feedstock while other developing nations are rapidly catching up. In this perspective, a sustainable nexus between Biofuels-Pesticides-Agroforestry (BPA) is essential to create a sustainable roadmap toward the UN SDGs, to fulfilling the energy, food, and land security. The contribution of technologies in BPA includes genetic modified crops, integrated pest and weed management with controlled release pesticides, use of nano-biopesticides is being reviewed. As a whole, the concept of biofuel processing complex (BPC) and farmers upskilling, together with the effective implementation of efficient policies and Internet of Things (IoT) would be the key to drive the BPA nexus towards fulfilment of SDGs.

Leveraging blockchain concepts as watermarkers of plastics for sustainable waste management in progressing circular economy.

Blockchain-integrated waste management and circular economy are emergent concepts that target minimising waste generation and fluctuations of resource commodity. Blockchain can support a circular economy and green principles by enabling information transparency, reliability and automation. Redesigning plastics by molecular tagging is the way forward to ensure synthetic plastics are kept in an infinite loop and support closed-loop recycling. The involvement of major corporations in product development and blockchain-integrated closed-loop recycling has resulted in several successful green chemical approaches toward circular plastic economy projects. Government policies and legislations are progressively supporting plastic redesigning for improving the plastic circular economy. Nevertheless, a systematic approach is required in addressing blockchain technology and plastic redesigning to effectively leverage circular economy initiatives.

Gasification of refuse-derived fuel from municipal solid waste for energy production: a review.

Dwindling fossil fuels and improper waste management are major challenges in the context of increasing population and industrialization, calling for new waste-to-energy sources. For instance, refuse-derived fuels can be produced from transformation of municipal solid waste, which is forecasted to reach 2.6 billion metric tonnes in 2030. Gasification is a thermal-induced chemical reaction that produces gaseous fuel such as hydrogen and syngas. Here, we review refuse-derived fuel gasification with focus on practices in various countries, recent progress in gasification, gasification modelling and economic analysis. We found that some countries that replace coal by refuse-derived fuel reduce CO2 emission by 40%, and decrease the amount municipal solid waste being sent to landfill by more than 50%. The production cost of energy via refuse-derived fuel gasification is estimated at 0.05 USD/kWh. Co-gasification by using two feedstocks appears more beneficial over conventional gasification in terms of minimum tar formation and improved process efficiency.