Reverse combustion from nanoparticles

Copper nanoparticles ( spheres) embedded in carbon nanospike

An accidental discovery was made, when a catalyst made of carbon, copper, nitrogen and applied voltage to trigger complicated chemical reaction that reverses the combustion process. Using nanotechnology-based catalyst which contains multiple reaction sites, the solution of carbon dioxide dissolved in water turned into ethanol with a yield of 63%! Usually, this type of electrochemical reactions results in a mix of several different smaller products. Though it is difficult to go from carbon dioxide to ethanol with a single catalyst, researchers discovered that the catalyst’s novelty lies in its nanoscale structure, consisting of copper nanoparticles embedded in carbon spikes. This approach avoids the use of expensive or rare metals such as platinum that limit the economic viability of many catalysts. By arranging common materials with nanotechnology, researchers were able to limit side reactions and end up with the desired product. The initial analysis suggests that the spiky textured surface of catalysts provides ample reactive sites to facilitate the CO₂ to ethanol conversion. Since materials are low cost and the fact that this reaction occurs at room temperature in water, it is possible that the approach could be scaled up for industrially relevant applications, such as, storing excess electricity generated from variable power sources such as wind and solar.

Song, Y., Peng, R., Hensley, D. K., Bonnesen, P. V., et al. (2016), High-Selectivity Electrochemical Conversion of CO₂ to Ethanol using a Copper Nanoparticle/N-Doped Graphene Electrode. ChemistrySelect. doi:10.1002/slct.201601169

The Next Bug Thing

Bugs might not be the first option that pops into your head when you get hungry, but it could certainly be an environmentally sustainable alternative to consuming meat. A report from the Journal of Agricultural and Food Chemistry examines how the nutrient content from certain insects can measure up to the nutrient content from beef (particularly, iron), opening the possibility of an alternative for our dietary needs. 

Some Eastern and South American cultures have seen their fair share of critters in their diets. Around 1,900 different species of insects are documented as a food source around the globe. Insects have been established as a source of protein, but recent findings show that iron is also another nutrient that bugs can give us. Iron is often lacking from non-meat diets, causing multiple complications (such as iron-deficiency anemia or poor pregnancy outcomes). 

The research analyzed the most commonly eaten insects for their mineral contents and used a lab model of human digestion to estimate how much of each nutrient would get absorbed. Grasshoppers, crickets, mealworms and buffalo worms were some of the chosen insects, and they showed varying levels of iron, calcium, copper, magnesium, manganese, and zinc. Surprisingly, minerals like calcium, copper and zinc are more readily available for absorption than the same minerals from beef. 

Figure 1. Different levels of Iron uptake depending on the type of insect, compared to the iron uptake from meat. Credit: American Chemical Society 

Reference: 
 Gladys O. Latunde-Dada, Wenge Yang, Mayra Vera Aviles. In Vitro Iron Availability from Insects and Sirloin Beef. Journal of Agricultural and Food Chemistry, 2016; DOI:10.1021/acs.jafc.6b03286

What is up with the algal toxins?

By: Lesly Hernandez

Recently harmful algal blooms have been increasing worldwide. They are a threat to aquatic species and might also be harmful to humans’ health. Some cyanobacteria produce microcystins (MC) which is a toxin that inhibit the activity of protein phosphatases. MC is accumulated by different aquatic animals which then transfer the toxic to other animals after consumption. The research describes the movement of algal toxins from aquatic food webs into riparian food webs by measuring the MC concentrations in different animals (mayfly, nidges, caddisflies, spiders, and Prothonotary Warblers). They also analyzed the concentrations between aquatic and terrestrial prey to check if growth rates are affected by the exposure to MC. The highest toxin concentrations were found in spiders and in the livers of nestling warblers. Aquatic insects had twenty times higher levels of MC than terrestrial prey which explains how riparian consumers are exposed to the toxins. Furthermore, MC levels did not correlate with warbler body condition or growth rate. The research shows that algal toxins are not only present in aquatic life but also in other food webs. We have to do something to stop the algal toxins from being passed on from aquatic systems to terrestrial food webs. More research needs to be done to improve the understanding of risks to humans and other living organisms that consume products that have algal toxins.

Figure 1. Concentrations of the algal toxin MC among terrestrial insects, aquatic emerging insects and riparian consumers from the James River Estuary in Virginia (Moy et al., 2016, http://pubs.acs.org.tamiu.idm.oclc.org/doi/pdf/10.1021/acs.est.6b02760).

Reference

Moy, N. J., J. Dodson, S.J. Tassone, P.A. Bukaveckas, and L. P. Bulluck. 2016. Biotransport of Algal Toxins to Riparian Food Webs. Environmental Science & Technology. 50:10007-10014                                                                                        

The Return of the Waste

Author: Grecia Guardiola

Figure 1. A boy holding a glass of water contaminated with arsenic and another one with potable water. 

Spain and India have long surpassed healthy levels of arsenic in their drinking water. This is highly alarming, since arsenic is known to be poisoning and can eventually lead to organ failure. In this experiment, two techniques were tested in order to understand and compare their effectiveness in their removal of arsenic. The first technique was adsorption, which used activated alumina as an absorbent, while the second d technique was an ion-exchange that used resins. Both techniques were noted to have trade-off; as arsenic was removed from the water, a hazardous pollutant containing the spent absorbent or resin was released (et al. Dominguez-Ramos 2014). Thus, these techniques increased environmental damage, as opposed to decreasing it. What is interesting though it the fact that activated alumina did not create as much solid waste as resins. This study advanced environmental sustainability by highlighting the importance of proper waste management and promoted future research to test other techniques (et al, Dominguez-Ramos).

References

Dominguez-Ramos, A., Chavan, K., García, V., Jimeno, G., Albo, J., Marathe, K. V., Yadav, G. D., and A. Irabien. 2014. Arsenic Removal from Natural Waters by Adsorption or Ion Exchange: An Environmental Sustainability Assessment. Ind. Eng. Chem. Res. Doi:1010.1021/ie4044345

Recycle your monitors!

     

 

       Liquid Crystal Display (LCD) is the most commonly used in television, computer monitors, and other common display panels today. It is very efficient due to its many advantages of light quality, small volume, and low power consumption, but does carry a life span of only 3-8 years. Nowadays everyone owns at least one television in their homes, and after a handful of years we are sitting with a very large quantity of LCD panels ready to be disposed of or due for treatment. In addition to this, LCD panels mainly contain inorganic materials (glass substrate) and organic materials (polarizing film and liquid crystal). The organic materials should always be recycled first due to the contents disadvantage to of the indium recycling process. This study was done to find a the most efficient and environmentally friendly way possible to obtain acetic acid from the was panels by using a sub/supercritical water treatment. The study showed a high percentage of organic materials were being removed presenting the current technology to be very efficient. A good percentage of acetic acid was also obtained, which provides important fossil energy based chemical product. The study also resulted the supercritical water was acting as an ideal solvent, a requisite reactant as well as an efficient acid-base catalyst, which is quiet significant according to the “Principle of Green Chemistry.” In conclusion, this study showed the organic matters in LCD panels to be recycled without any environmental pollution, and it provided for new opportunities to alternate fossil-based chemical products for sustainable development in the matter of converting “waste” into “fossil-based chemicals.”

R.Wang, Y. Chen, and Z. Xu. 2015. Recycling Acetic Acid Polarizing Film of Waste Liquid Crystal Display Panels by Sub/Supercritical Water Treatments. Critical Reviews in Environmental Science and Technology. 49: 5999-6008.

Silver's Shape Does Matter!

By: Melissa Bracero

Figure 1: Set of TEM images of silver nanomaterials. A) Spherical silver nanoparticles. B) Silver nanocubes. C) Silver nanowires. 

Silver, a commonly used nanomaterial, is used in plenty of consumer goods like athletic clothing, toys, food storage containers, and wound wrappings. There has been a lot of work in studying toxicity of silver nanomaterials, but not enough in studying shape-based toxicity. In this experiment, spherical silver nanoparticals, silver nanocubes and silver nanowires are tested through multiple methods. These include silver nanomaterial synthesis, nanomaterial characterization, plant toxicity measurements using Lolium mutiforum, bacterial tests (3 different bacteria) and statistical analysis. Each silver shape had same surface coating and the size was kept constant, in order to properly compare to each other. The results showed that shape of nanomaterials can affect toxicity. Silver nanocubes are less toxic towards plants than spherical silver nanoparticles, but had similar bacterial toxicity. This article suggests that effective shape engineering could allow for desired properties of silver nanomaterials, all while avoiding unwanted side effects in the environment. However, shape is not the only factor that contributes to the final toxicity of nanomaterial in the environment. Yet, having shape control and an understand of shape-depended properties of silver nanomaterials is an area that can bring many surprises to science.

Reference

 

Gorka, D. E., Osterberg, J. S., Gwin, C. A., Colman, B. P., Meyer, J. N., Bernhardt, E. S., . . . Liu, J. (2015). Reducing Environmental Toxicity of Silver Nanoparticles through Shape Control. Environmental Science & Technology Environ. Sci. Technol., 49(16), 10093-10098. doi:10.1021/acs.est.5b01711

Is industrual waste industrial loss?

    Is industrual waste industrial loss?


        By: Carlos A. Resendiz

        Industrial production pushed forward society by the large production of consumption goods. But what happens with the waste produced? How many waste is produced consequently of these goods? Is there a balance is the production of these goods sustainable for planet earth? Large amount of waste is produced by the process of industrialization. The production in masses have a negative impact in the environment. The wastes can be summed as wastewater, solid materials, byproducts, and waste gases. In China, this is not an issue anymore. China has incentivized the reuse of industrial wastes as primary source of production. ‘‘Comprehensive Utilization of Resources (CUR)’’ policy give rise to the recycle of waste materials for industrial production. Recent studies compared life cycle inventories for the same product from baseline and CUR- certified production to determine the benefits of this policy. The results showed a positive impact in the reduction of pollution due to industrial waste. More than 50 million tons of solid waste, reduction of 161 petajoules of energy, and 23 million tons of CO₂ is the result for this change to ‘‘Green Industrial Production’’. This should be example for more nations in order to decrease the pollution rates due to industrialization around the world. China has started the change, more nations should follow these steps in order to develop a more sustainable global environment.

Fig 1. Sketch of how the industrial waste is recovered 

by ''Greening Industrial Production through waste recovery''

Reference

Zhu, J., & Chertow, M. R. (2016). Greening Industrial Production through Waste Recovery: “Comprehensive Utilization of Resources” in China. Environmental Science & Technology Environ. Sci. Technol., 50(5), 2175-2182. doi:10.1021/acs.est.5b05098