By Samantha Zaluski
Today, fresh water is becoming more and more valuable. The world is covered mostly by salt water, which is not useful for drinking. A practical and economical process of desalinization of salt water is still under development. The primary article, from Environmental Science & Technology, “A New Method for Water Desalination Using Microbial Desalination Cells”, by Bruce E. Logan and others was published on July 24, 2009. This article is about using organic matter and bacteria to remove salt from salt water while producing power. The article “Bug power makes salt water sweet” by Ewen Callaway in New Scientist was posted on August 24, 2009. The article discusses how Logan’s team developed a new way to desalinate water. Although the two articles discuss the same experiment and findings, they are very different in style and breadth of discussion of results.
The style of Logan’s article is very organized and technical and uses a realistic and factual tone. It is split up into sections: Abstract, Introduction, Materials and Methods, Results and Discussion. Logan uses scientific terms such as “cathode”, “anode”, “cation exchange membranes” and “anion exchange membranes”. His audience would primarily be scientists, who would understand this vocabulary. The primary article discusses the chemistry of the process in great detail. The style of Callaway’s article is more informal and is written in a hopeful and optimistic tone. He uses terms such as “positive and negative charges” and “semi-permeable membranes”, more suitable for his intended audience of non-scientists who are interested in science. Callaway’s article starts with an introduction then discusses the results of the experiment and ends with speculation on the future of these findings. The two articles are different in that Logan’s article is written in a scientific and technical style and Callaway’s is informal and optimistically speculative. They are similar in that they both are written in an organized manner. Both styles are suitable for their intended audiences.
The discussion of the results in the primary article is thorough and detailed. How the voltage generated and level of desalination varied over the cycle of desalination was graphed. The results for three different salt concentrations and their level of accuracy are stated: “88 ± 2% (5 g/L), 94 ± 3% (20 g/L), and 93 ± 3% (35 g/L)” (Logan, 2009). They found that the max voltage was 600 mV during microbial desalinization with a initial salt concentration of 20 g/L and a 200ohm resistor. They observed almost 100% charge transfer efficiency between electrons harvested and NaCl removal. Logan says “About 90% of the salt was removed from the water over a single desalination cycle, and there was no need to pressurize the water or use an external source of electricity” (Logan, 2009). As well, Logan's article lists and discusses the numerous limitations of the research and its results. The discussion of the results in the secondary article is general and summarized and very brief. Callaway says “The device removed between 88 and 94 per cent of the salt from various salt-water solutions, including one that approximated seawater” (Callaway, 2009). The secondary article does mention the limitation that Logan's experiment did not demonstrate an economical method of desalination. The two articles are similar in that they both state the evidence and discuss how Logan’s team came up with the results. They are different in that the primary article details not only the results but their accuracy and limitations, whereas the secondary article summarizes the results in a single sentence, and really only discusses a single limitation, which is cost.
These two articles are slightly similar in organization but are very different in language, tone and discussion of the results. The secondary article was very successful at summarizing the primary article for its readers, but before concluding that an economical desalination process will be developed on the basis of Logan's research alone, the reader would definitely need to carefully read the discussion section of the primary article, where all the limitations of the research are thoroughly detailed.
References:
Callaway, Ewen . “Bug power makes salt water sweet” New Scientist. 24 August 2009 Retrieved October 5, 2009 http://www.newscientist.com/article/dn17667-bug-power-makes-salt-water-sweet.html
Logan, Bruce E. and Team. “A New Method for Water Desalination Using Microbial Desalination Cells”. Tsinghua University, Beijing, China, and Engineering Environmental Institute, Penn State University, Pennsylvania. DOI: 10.1021/es901950j. July 24, 2009 http://pubs.acs.org/doi/full/10.1021/es901950j?cookieSet=1
Your discussion of the vocabulary used in the two articles was interesting; it's true that the two different audiences (a scientifically educated one, and a more general one) may come from different backgrounds which could understand less the scientific words. This is the same for the organization, and amount of detail, and everything else, you highlighted well what the difference in audience does to the content. Interesting.
ReplyDeleteI thought you did a really good job of comparing the two articles. It was very effective the way you used the most dramatic examples from the two sources. I thought that the author of your secondary article did a good job of explaining how such a complicated procedure is done. He didn't include unnecessary scientific details and language but stated the procedure so that anyone could understand. (which proves the different purposes of the sources)
ReplyDeleteI found it interesting how you captivated the different perspectives of the scientist vs non-scientist. The only part of your article I found a bit confusing was the structure. It might be a little easier from an outsider point of view if your ideas had a bit more flow. Other than that it was great, I too enjoyed your discussion on the different terminology used.
ReplyDeleteYour review was excellent in its comparison of the two articles. The format was clear, each idea introduced and concluded in a way that made it easy to understand and follow. However, in my opinion, the second body paragraph of your work should describe less evidence (it contains many examples from the text) instead discussing the implications of how the method and limitations were presented in each article. Good work on the argument regarding audience and the style of the articles.
ReplyDelete