Blog Post #10 - Jialin Wang

Article Title: Reclaimed Wastewater for Drinking: Safe but Still a Tough Sell

Author of Article: Ker Than
Publication: National Geographic News
Publication Date: January 31, 2012

Link: http://news.nationalgeographic.com/news/2012/01/120131-reclaimed-wastewater-for-drinking/

Image Source

Picture:
The picture to the left shows treated wastewater, or reclaimed water. Reclaimed water is currently being used mainly in agriculture and industry, but filtration technology can make it safe for humans to drink. In fact, many towns are already using recycled water.

Summary: Water usage is a major issue today. Aquifers are running dry because water is being pumped out faster than it can be replenished. Draining water from the ground and surface has serious negative repercussions for the environment. However, recycling wastewater may help to alleviate this problem. Current technologies for treating water are capable of keeping contaminants at a safe level for human consumption. In addition, updating regulations could further decrease the amount of organic and chemical pollutants. There is still the matter of implementation. In some cases, wastewater of one town is owned by the next one downstream. Furthermore, it would be necessary to convince the public that reclaimed water is safe to drink, and to overcome revulsion to the recycled water. Places like Singapore are taking steps in this direction; changing things gradually, and making it more economical to use reclaimed water.

Opinion/Reflection:
Given that treated wastewater is just as clean as the water we currently use, I think it makes sense for it to be used for drinking. After all, human beings are remarkably adaptable, and really, this is a small change, one that could be greatly beneficial. We would take less water from aquifers and other slowly-replenished sources, allowing them to recover and making our water usage more sustainable. This would also be helpful to the wildlife that relies on water sources, such as lakes and rivers, that we currently take water from, as there would be more water to support their ecosystems.

Questions:
1. Would you drink reclaimed water? Why or why not?
2. How can the psycological aversion to drinking reclaimed water be reduced?
3. What effect would making reclaimed water part of our water supply have? On the environment? For people? Something else?

Blog Post #9 - Nick Jaeschke

Nitrates in Drinking Water

Nick Jaeschke

This map illustrates aquifers vulnerability to nitrates, a compound of nitrogen and oxygen that, in great quantities, can be dangerous.

Image URL:http://thewatchers.adorraeli.com/wp-content/uploads/2012/03/nitrates1.png

Summary

Nitrate is a compound consisting of one nitrogen atom and three oxygen atoms. The compound is colorless, odorless, and tasteless. Nitrate has recently been found in water supplies in Colorado. Its MCL is 10 mg/L. Consuming great quantities of nitrates can cause methemoglobinemia. This diseases replaces the hemoglobin, the element in your blood that transports oxygen around your body, with less efficient methemoglobin. This can lead to damage in vital tissue. For most people, consuming nitrates is not that big of a deal, but it can be very bad for babies, since older people have many enzymes that convert methemoglobin back into hemoglobin, while babies have little to none. For livestock, great levels of nitrate can lead to nitrate poisoning in ruminant animals such as cattle and sheep. Once nitrates are in a water supply there are four different ways one can remove it: distillation, boiling the water to leave the minerals behind; reverse osmosis, water is forced through a membrane that filters out nitrates; ion-exchange, replacing the nitrate with another substance such as chlorine; and blending, mixing pure and impure water to lower the concentration levels.

Opinion/Reflection

I was surprised that this form of nitrogen could be so potent. I knew that nitrogen is needed to make new DNA, and that living things can only use specific nitrogen, nitrite. Nitrate is atmospheric nitrogen, and has that triple bond that nitrogen fixing bacteria need to break, but it is unbelievable how much of a difference that one bond makes. I was also interested by the means of removal. Only distillation and reverse osmosis actually remove the nitrates. Ion-exchange only changes the contaminant, and blending just lowers the concentration to safer levels.

Questions

1) The article was written by Chicago citizens. Do significant amounts of nitrate appear in our water supplies? If not, why?

2) Is the presence of nitrates in a water supply an extreme problem? Is the substance that dangerous? Why or why not?

3) Is “blending” safe? Is it ethical? Would you drink water if you knew it was “blended”?

Article Information

Title: Nitrates in Drinking Water

Authors: J.R. Self and R.M. Waskom

Publication Date: Tuesday, March 26, 2013

URL: http://www.ext.colostate.edu/pubs/crops/00517.html