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Water Purification to Drink

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楼主
发表于 5-22-2011 10:49:09 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
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(1) Background:
(a) The situation worldwide is kind of bad, and getting worse.  
(i) world population
http://en.wikipedia.org/wiki/World_population
(6 billion in 1999; 7b at present; possibly 9b in 2050)
(ii) Taiwan records annual rainfall of 2,500mm on average. Once in a blue moon (such as a month ago), however, a short period of drought casts its pall and water rationing is required.
(iii)  At Shaanxi Normal University co-eds were coaxed into peeing standing over a urinal in September 2010, principally to save water.
(iv) 中国华中遭遇“五十年不遇大旱.” BBC CHinese, May 22, 2011.
http://www.bbc.co.uk/zhongwen/simp/chinese_news/2011/05/110522_china_drought.shtml

My comment: China every now and then uses dramatic terms such as 年不遇. It is just silly.

(b) Drinking treated waste water (urine is actually very clean).*

* Chinese ate shit unflinchingly. See
John Pomfret, The Life and Times of Book Idiot Zhou; Zhou Lianchun's transformation from brutal Red Guard to successful entrepreneur is the story of the new China. Washinton POst, July 16, 2006
(excerpt from his book Chinese Lessons: five classmates and the story of the new China. Henry Holt and Company, 2006, at page 21: In a torment session, "'Eat shit,' she [mother] screamed at her assailants. "Eat shit!" Zhou [her son, who happily schemed against his mother] was then dispatched to a nearby outhouse to collect shit in a wooden bucket and dilute it with water. The Red Guard chief took a wooden ladle and poured the runny concoction down her throat. She kept quiet after that.")


(i) Kathy Chu, Astronauts drink recycled urine aboard Space Station. USA Today, Mar 3, 2011.
http://www.usatoday.com/money/industries/environment/2011-03-03-1Apurewater03_VA_N.htm

Quote:

"NASA first began recycling urine aboard the International Space Station in 2009,

"Unlike the recycling system that places such as Orange County, Calif., and Singapore use, which involves filtering wastewater through a membrane, NASA distills its water. Basically, heat is applied to separate water from waste.

(ii) Kathy Chu, From toilets to tap: How we get tap water from sewage. USA Today, Mar 3, 2011.
http://www.usatoday.com/money/industries/environment/2011-03-03-1Apurewater03_CV_N.htm
(Windhoek, Namibia; Fairfax Water in Northern Virginia; parts of Orange County, Calif

Quote:

"Once heavily dependent on neighboring Malaysia for its water supply, Singapore is unapologetically recycling sewage and other wastewater in a way that the city-state believes will help make it self-sufficient. * * * By 2060, it expects its purified wastewater to accommodate half of the nation's water demand. * * * Besides what it imports and recycles, Singapore gets water from local catchments and desalination.

"Despite the not-so-pleasant nickname — 'toilets to tap' — given to the technology, only about 10% of household wastewater typically comes from toilets, while the rest comes from showers, sinks and laundry machines, says Michael Markus, general manager of the Orange County Water District (OCWD). Orange County also recycles industrial wastewater.

"In the USA, the Environmental Protection Agency regulates tap water, and its rules for treating the water are generally stricter than those imposed on bottled water, under the purview of the Food and Drug Administration. No federal law governs recycled wastewater for drinking

Note: Takashi ASANO 浅野 孝

(2)
(a) Karin Kloosterman, Drinking Water for China, Israeli Style. Israel21c, May 5, 2011.
http://www.israel21c.org/201105059021/environment/drinking-water-for-china-israeli-style

Quote from three consecutive paragraphs:

"Created in Tianjin, China, the Israeli-built IDE MED desalination plant is the country's largest and greenest one yet, says IDE's CEO, Avshalom Felber. Using a process called multi-effect distillation (MED), the plant is claimed to be 50 percent more energy efficient than any other thermal desalination plant today.

"In IDE MED, salt water from the sea is heated with steam and then circulated through an evaporator to create an end result of fresh water and salt.

"The green element in the design is that the steam used to heat the water before the evaporation process comes from a nearby power plant, making sure that some wasted energy is put to good use.

Note:
(i) About Us. Israel21c, undated.
http://israel21c.org/general-content-about-us-category/about-us
("ISRAEL21c is a non-profit educational foundation with a mission to focus media and public attention on the 21st century Israel that exists beyond the conflict")
(ii) IDE Technologies Ltd
http://www.ide-tech.com/
("founded in early 1960s"; based at Kadima, Israel)

(b) Relevant reports from Economist magazine.
(i) Another Green World; Like Easter Island, Ascension Island has lessons for the planet—cheerful ones. Economist, Dec 16, 2010
http://www.economist.com/node/17722704
(From a pile of rocks, the island is transformed into a paradise, which hosts US and British military bases)

My comment:
* Please read only the first five paragraphs of the section headlined "Building a new Eden."
* "The Island is named after the day of its recorded discovery, Ascension Day."
http://en.wikipedia.org/wiki/Ascension_Island
(ii) A special report on smart systems | Making Every Drop Count; Utilities are getting wise to smart meters and grids. Economist, Nov 4, 2010
http://www.economist.com/node/17388318
(By the mid-2000s London had one of the leakiest water-supply systems in the rich world. Every day nearly 900m litres of treated water were lost and 240 leaks had to be fixed. London has replaced old water pipe and put sensors and actuators (devices to control a mechanism) in them--pipes--which "not only automatically deal with leaks but also schedule work crews and send text messages to affected customers")

Note: The portion of this article that concerned Singapore is:
* Singapore is starting implementing the smart system of sensors and actuators;
* "The city-state’s desalination plants are also among the world’s most efficient. All this means that the island—smaller than Luxembourg and home to nearly 5m people as well as an economy nearly as big as that of Hong Kong—is able to meet more than 60% of its water needs on its own. But it wants to go even further: 50 years from now it hopes to be self-sufficient."
(iii) Dated May 20, 2010 Economist had a special report on water whose summary is as follows.

Water  |  The world's Most Valuable Stuff; Mostly because of farming, water is increasingly scarce. Managing it better could help. Economist, May 20, 2010
http://www.economist.com/node/16163366
("Desalination looks more hopeful, since new technologies are being developed and prices are falling. But it is still expensive, especially in terms of energy use, which is why at present it provides only 0.4% of the world’s fresh water")

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沙发
 楼主| 发表于 5-22-2011 16:15:58 | 只看该作者

Re: Water Purification to Drink

本文通过一路BBS站telnet客户端发布

A Chinese comments: "问题是北方冬季这些RO 处理的水量严重下降,需要加热水温,这又是一块大成本."

(1) I have never been to China--or read China's media except People's Daily now and then).

Bohai does fereeze up in winter:
He Na and Zhao Ruixue, In Bohai, All at Sea on the Ice. China Daily, Jan 27, 2010.
http://www.chinadaily.com.cn/china/2010-01/27/content_9381068.htm

Still seawater can be drawn under the ice cap for reverse osmosis (RO).

(2) Problem is Temperature Correctiuon Factor (TCF).

(a) Reverse Osmosis Systems Flow Rate Changes With Temperature. APS TechNotes, APSWater, undated.
http://www.apswater.com/article.asp?id=181&title=Reverse_Osmosis_Systems_Flow_Rate_Changes_With_Temperature

There are various TCF formulas out there. In other words, they are not the same--not even similar (why? I do not know).

(b) Dow Chemical Company has a detailed explanation.

FILMTEC Membranes - Effect of Temperature on Permeate Water Quality. July 13, 2009 (Answer ID 1241).
https://dow-answer.custhelp.com/app/answers/detail/a_id/1241/related/1/~/filmtec-membranes---temperature-correction-factor-(tcf)

My comment: Skip text (because I could not understand it, either) and go directly to the links below it (text):

(i) "Additional Information:

Factors Affecting RO Membrane Performance (65KB PDF)"

In the PDF document, read
* Definitions at page 1 for "Rejection" and--more important, "Permeate" (which basically means the water that passes through the RO membrane).
* text for
Figure 2. Effect of Feedwater Pressure on Flux and Salt Rejection
Figure 3. Effect of Feedwater Temperature on Flux and Salt Rejection

(ii) "FILMTEC Membranes - Operating Temperature Limit"
("[Q:] Can I operate FILMTECTM membranes at a temperature greater than 45°C (113°F)?
[A:] Elements are not designed to support the temperature higher than 45°C  (113°F).")


【 在 choi 的大作中提到: 】
: (1) Background:
: (a) The situation worldwide is kind of bad, and getting worse.  
: (i) world population
: http://en.wikipedia.org/wiki/World_population
: (6 billion in 1999; 7b at present; possibly 9b in 2050)
: (以下引言省略...)

--
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