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The Photosynthetic CO2 Race − Plants vs. Algae

Algae store CO2 but also release it. Some of us may know that. However, so far it was unknown that algae may release additional CO2 due to global warming. That’s what researcher Chao Song and his colleagues of the University of Georgia in Athens, GA, found out.

As they published in the journal Nature Geoscience, the metabolism of algae and other microbes is accelerated by higher water temperatures in large streams. This could lead to some rivers releasing more CO2 than they do now. This could, in turn, further accelerate global warming. Although photosynthesis in algae would accelerate, plants along the river banks would be even faster. Decomposition of the plant material would immediately release the so fixed CO2. With extra nutrients from plants, competing microorganisms would overgrow the river algae or the algae would degrade the plant material themselves.

To calculate the CO2 net effect, scientists monitored temperature, dissolved oxygen, and other parameters in 70 rivers worldwide. Then they used their data for computer models. These models suggest that over time, accelerated photosynthesis in some rivers may not keep pace with plant growth. This net increase of 24% of the CO2 released from rivers could mean an additional global temperature increase of 1 °C.

However, the computer model still lacks some data. For example, the sedimentation rates are not taken into account. In addition, not all banks grow plants. Many rivers pass only sparsely vegetated land. As always, more research is needed to get better answers.

(Photo: Wikipedia)

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Cobalt Nanocrystals Make Lithium-Ion Batteries Age More Slowly

In todays Li-ion batteries, cobalt oxide cathodes improve performance and durability. While, such cobalt cathodes show the same performance as nickel oxide cathodes, they come at a higher price. Nickel cathodes, in turn, crack and dissolve quickly, which reduces their lifespan. Nevertheless, nickel cathodes are very popular because they are so cheap.

Now, the research team led by Jaephil Cho of the Ulsan National Institute of Science and Technology in South Korea has developed a cathode made of more than 80% nickel. The researchers reported in the journal Energy & Environmental Science that a cathode coated with nanocrystals of cobalt aged more slowly than conventional nickel cathodes. After recharging 400 times at room temperature, the battery was able to retain 86% of its original capacity.

The novel nickel cathodes could help meet the growing demand for rechargeable batteries in electric vehicles if cobalt prices rise in the future.

(Photo: Wikipedia)

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Decarbonizing Planet Earth – Nuclear vs. Renewable

Adding to the controversial scientific debate whether renewable or nuclear energy decarbonize the atmosphere quicker, Lovins et al of the Rocky Mountain Institute in Basalt, Colorado, argue that renewable energy is doing a better job. In their recent study, published in Energy Research & Social Science, they analyzed 17 years of recent energy resource development worldwide to support their conclusion. Their paper stands in contrast to numerous previous studies, including a 2016 report published by Cao et al in Science, claiming that nuclear power is better suited for fast decarbonization. However, the nuclear waste problem still remains unresolved.

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Starting up Power-to-Gas Reactors

In their paper “Effect of Start-Up Strategies and Electrode Materials on Carbon Dioxide Reduction on Biocathodes“, which was recently published in Applied and Environmental Microbiology, Saheb-Alam et al. teach us how to start-up bio-electrical systems for CO2 conversion to methane gas. They compared pre-acclimated with pristine electrodes and found that there is no difference in start-up time. Their findings stand in contrast to previous observations where pre-acclimation has indeed helped to improve reactor performance. For example, LaBarge et al. found that electrodes acclimated with methane-forming microbes, called Methanobacterium, do reduce start-up time.