The presence of microplastics in the environment has increased due to anthropogenic activities; it is estimated that 15 million kilograms of plastic waste accumulate in the ocean annually. Pollution permeates every inch of the ocean from microplastics in the food chain to plastic water bottles floating on the surface. This monolith of ocean pollution is made up of all kinds of marine debris and contains 1.8 trillion pieces of plastic, covering an area twice the size of Texas. The objective of this review is to show advances in the study of emerging problems, specifically in the presence of microplastics in water and soil and their potential effects on health. In addition, microplastics have synergy with residual contaminants that exist in the water such as textile waste, organic matter, pathogens, etc. This causes damage to aquatic organisms as it makes nutrient transfer more complex in many of these species. There is a report that estimates that liabilities related to plastic pollution will cost the industry 100,000 million dollars due to lawsuits for damages and losses, of which 20,000 million will occur in the United States. The study of the presence of microplastics in the environment can generate indicators of the current effect to generate public policies that try to control the growth of this pollutant in the environment. It is important to discuss all the routes of generation of microplastics, distribution, and cosmetics involved in fast fashion with glitter and to evaluate the physical, chemical, biological, and toxicological effects on the environment, proposing the path and future to be followed regarding this research topic.
Global population growth requires the use of various natural resources to satisfy the basic needs of humanity. Fossil fuels are mainly used to produce electricity, transportation and the artificial air conditioning of habitats. Nevertheless, countries around the world are looking for alternative energy sources due to the decrease in the availability of these fuels and their high environmental impact. The mixture of hydrogen and carbon monoxide (H2 + CO), commonly called syngas, is a high-value feedstock for various industrial applications. By varying the composition of syngas, especially the H2/CO molar ratio, it can be used to produce methanol, fuels or synthetic natural gas. However, when this ratio is very low, the separation of this gas usually represents a great problem when making the energy balance, which is why it is proposed to adapt a combustion process in chemical cycles, taking advantage of the energy of this gas, reducing the energy impact of the process. During the present project, mass and energy balances were developed for combustion in chemical cycles, using ilmenite as a carrier, integrating heat exchangers to take advantage of the residual energy at the output of the process, to preheat the inlet current in the regenerator. Here, a comparative was made at different temperatures of the air stream and evaluating the mechanism of the ilmenite when a syngas stream is used as fuel.
Currently, energy generation based on fossil fuels is producing negative environmental impacts; two of the main symptoms of these impacts are water pollution and climate change. Consequently, the search for new technologies to satisfy the energy demand must have the goal to minimise possible impacts to the environment. There are alternatives with biofuels and, among them, biodiesel. The cheapest reaction pathway for biodiesel production is the transesterification of triglycerides by methanol in the presence of sodium hydroxide; however, this option can contaminate large volumes of water used in the final leach of the biodiesel product. Therefore, a feasible way of producing this biofuel while simultaneously minimising leaching water will be environmentally friendly and will improve economical savings. The present study developed an experimental design in order to minimise the addition of NaOH during biodiesel production by the basic homogeneous pathway. The best operating conditions were 46 °C, methanol in situ 7.5% v/v and NaOH 0.035 M. These conditions allowed to reduce the leaching water amount by 25% compared to techniques reported in the literature; however, the yield to biodiesel decreased from 98 wt.% to 87 wt.% when a model waste oil was used instead of virgin oil.