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Dutch Town Lays Air-Purifying Concrete 295

Posted by CmdrTaco
from the i-hate-august-news-cycles dept.
eldavojohn writes "In an effort to combat air pollution, a Dutch town has paved some of its streets with air-purifying concrete. It contains a titanium dioxide-based additive that utilizes sunlight to turn car exhaust into harmless nitrates. It was shown to do this in a lab and now the scientists are interested in just how much this will affect the air quality around the road. They will sample the air quality by a normal road and by this newly paved one."
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Dutch Town Lays Air-Purifying Concrete

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  • Offset? (Score:5, Insightful)

    by Recovering Hater (833107) on Wednesday August 06, 2008 @12:12PM (#24498239)
    Because the purifying concrete offsets the pollution incurred from mining the titanium to create the concrete? Am I wrong in thinking I knew an old lady who swallowed a fly? Someone weigh in on this please. Thanks :P
    • Re:Offset? (Score:4, Insightful)

      by Anonymous Coward on Wednesday August 06, 2008 @12:16PM (#24498299)
      This one is obviously about enhancing the air in the city. It is not supposed to solve any large scale problems with the climate. Didn't RTFA.
      • Re: (Score:3, Informative)

        You should have. They're only paving one side of the street with it. This way they can test the air quality on either side of the street and see if there's any difference.
        It's an experiment.
        Couldn't see anyone doing 'testing' in a town in the US without two very big teams of lawyers being involved.
        Yeah innovation!

        • Re: (Score:3, Informative)

          by paanta (640245)
          Government agencies like the DOT does testing all the time. Ever pass a sign on the highway saying you're going to be on experimental pavement for the next 500'?
        • Re: (Score:3, Funny)

          by MrKaos (858439)

          They're only paving one side of the street with it. This way they can test the air quality on either side of the street and see if there's any difference.

          Now we know why the chicken crossed the road!

          bad-duum-tish!!!

    • Re:Offset? (Score:5, Insightful)

      by hardburn (141468) <hardburn@wumpus-cav e . n et> on Wednesday August 06, 2008 @12:18PM (#24498339)

      It might. If it works well enough, it would mean we could either remove catalytic converters from cars (which would increase engine efficiency), or promote the use of small diesels (which can be more fuel efficient but release a lot more NOx), and end up with a net win for smog pollution.

      In other words, it doesn't directly do anything greenhouse gases, but it does allow us to produce less greenhouse gases by using techniques that produce more nitrates.

      • Re:Offset? (Score:5, Insightful)

        by MillionthMonkey (240664) on Wednesday August 06, 2008 @12:55PM (#24499083)

        If it works well enough, it would mean we could either remove catalytic converters from cars (which would increase engine efficiency), or promote the use of small diesels (which can be more fuel efficient but release a lot more NOx), and end up with a net win for smog pollution.

        An exhaust-eating road surface is never going to be as efficient as a guy just chasing your car down the street with a big vacuum cleaner hose. I think we're keeping our catalytic converters.

    • Re: (Score:2, Insightful)

      by rjhubs (929158)
      I supposed it could work because the cost of getting titanium is a one time cost, but the effects of the concrete will continue working over time.
      • Re: (Score:2, Insightful)

        by Born2bwire (977760)

        It would depend on whether or not the titanium dioxide is acting as a catalyst or component of the reaction.

      • Re: (Score:3, Informative)

        by mrchaotica (681592) *

        Actually, there's a recurring cost for the concrete as well: it doesn't last forever, you know! It lasts longer than asphalt concrete, but it'll still need to be repaved after a few decades.

        (At least, it doesn't last forever the way we use it -- if we built like the Romans did, it'd last forever but cost a heck of a lot more.)

    • Re:Offset? (Score:4, Informative)

      by FireStormZ (1315639) on Wednesday August 06, 2008 @12:33PM (#24498669)

      The Titanium is not consumed in this process (merely a catalyst) so it might very well be worth it in the long run..

    • Re: (Score:2, Informative)

      by Bruiser80 (1179083)
      Titanium Dioxide is not a rare compound, just like Aluminum Dioxide isn't. Pure Aluminum or Titanium are rare.

      The original Crown Jewels contained Aluminum because it was a precious metal at the time. A chemical process was developed by Reynold around the 19th/20th century to convert a lot of Aluminum Dioxide into pure Aluminum using a small amount of pure Aluminum.
    • Re:Offset? (Score:4, Informative)

      by infolib (618234) on Wednesday August 06, 2008 @01:38PM (#24499827)

      the pollution incurred from mining the titanium

      This is not titanium, it's titanium dioxide which can be mined from the ground in some places. Wikipedia says that "The relatively high market value of titanium is mainly due to its processing" from oxide. Besides that, it's only needed in the surface, no need to fill the whole concret slab, just the layer that'll wear.

    • Re: (Score:3, Informative)

      by WebCowboy (196209)

      Am I wrong in thinking I knew an old lady who swallowed a fly? Someone weigh in on this please.

      No you're quite right, but not quite for the same reason. Concrete and asphalt already used in the roads are the result of intensive mining, drilling and refining processes already, and titanium can be recoverer/reused, so I'd venture to say that though there would be an added environmental impact to include this "air scrubber" additive that it isn't the biggest factor offseting the benefits to air quality.

      I'd say a more immediate concern is that this doesn't reduce pollution--it only converts it into anou

  • by dedazo (737510) on Wednesday August 06, 2008 @12:15PM (#24498277) Journal

    All passive filters I know require replacement because they get clogged, or the active elements eventually decay. Beyond making jokes about swapping the church bricks five years from now, TFA was a bit light on the details. Does anyone know how does this works, from a chemical perspective?

  • Wonder if there is a way to harvest them from the street.
  • Nitrates? (Score:5, Insightful)

    by ArcherB (796902) on Wednesday August 06, 2008 @12:16PM (#24498309) Journal

    Nitrates? Aren't those bad in their own right? I'm thinking along the lines of fertilizer run-off and the affect it has on algae in oceans. Could this solution create worse problems?

    • by dAzED1 (33635)
      I came in to comment on runoff into oceans as well. There's a huge area in the Gulf of Mexico that is dead - no oxygen, and thus no life, in the water. Now, I don't want to be so simple as to think all nitrates are created equal, but...
    • Re: (Score:2, Informative)

      by jascha.cohen (1130859)
      As i recall from my "environmental studies" class, it's not that nitrates are bad in-and-of-themselves, it's that when they accumulate in an area they can unbalance the system and create problems. Wikipedia has a decent article/overview on the topic. http://en.wikipedia.org/wiki/Nitrogen_cycle [wikipedia.org]
    • Re: (Score:3, Insightful)

      by AKAImBatman (238306)

      Plants need Nitrates to grow. (Nitrates == Nitrogen based chemicals.) So it should actually be positive for the soil rather than negative. I stress *should* because without knowing the exact chemical composition, it's hard to understand if there are any hidden problems with this technique.

      One thing I am worried about, though, is the color of these sidewalks. If they're using titanium dioxide, shouldn't they be a nice brown color? (Think: Coffee, cola, and other brown liquids.) I don't know about anyone else

      • Re:Nitrates? (Score:5, Informative)

        by bcattwoo (737354) on Wednesday August 06, 2008 @12:33PM (#24498661)

        "One thing I am worried about, though, is the color of these sidewalks. If they're using titanium dioxide, shouldn't they be a nice brown color?"

        Actually titanium dioxide is quite white. It is used as pigment for white base paint.

      • perhaps this technique is intended for use with blacktop rather than concrete as suggested by the article?

        I would imagine it wouldn't work very well with asphalt concrete because the asphalt would coat the titanium particles and block the NOx from getting to them.

    • Re:Nitrates? (Score:5, Interesting)

      by hey! (33014) on Wednesday August 06, 2008 @12:41PM (#24498829) Homepage Journal

      Anything is harmful in the wrong place and in the wrong concentrations. Nitrates are, for example harmful to fish in high concentrations.

      Most systems have processes that are limited by the supply of some resource. Ocean ecosystems are nitrogen limited, whereas fresh water systems tend to be phosphorous limited. Thus if the nitrates are washed off into fresh water, they'll cause relatively little immediate damage unless the concentrations are high enough to be toxic. However, if that nitrate is carried downstream to the ocean, the plume of nitrogen rich water entering the ocean can cause blooms of organisms that use up so much oxygen that fin fish suffocate. This happens where the Mississippi enters the gulf.

      So, how and where something like this is used makes a difference. If you imagine all the US cities along the Mississippi and its tributaries using it, and if there is a mechanism by which the nitrates make it into the rivers, then this could make the situation in the Gulf much worse. If you use it in a coastal city and only the runoff from that city affects the local ocean, the amount of nitrogen entering the ocean might or might not have any measurable effect.

      • by Sockatume (732728)
        Indeed, and I suspect the amount of nitrate produced would be pretty high. A quick google puts urban NOx production at the thousands of tonnes per day. Ignoring chemistry for the sake of simplicity, that'd equate to thousands of tonnes of nitrate being produced per day. If my maths is accurate. that's of the same order of magnitude as fertiliser nitrate runoff from the Mississippi to the Gulf of Mexico.
    • Re: (Score:2, Insightful)

      by Hal_Porter (817932)

      Nitrates? Aren't those bad in their own right? I'm thinking along the lines of fertilizer run-off and the affect it has on algae in oceans. Could this solution create worse problems?

      Well they make plants grow and that cuts down on the CO2.

    • Re: (Score:2, Informative)

      I knew somebody would say this... Its not the nitrates that do the harm, its the phosphates... Just a couple weeks ago this was reinforced... Source [slashdot.org]
      • Re: (Score:3, Informative)

        by clone53421 (1310749)

        Of [epa.gov]
        course [epa.gov]
        nitrates [wi.gov]
        are [state.wi.us]
        harmless! [state.ne.us]

    • Nitrogon oxides eventually end up as nitrates, the TIO just speeds up the process.

    • by amper (33785)

      Yes, this is a problem. Take a look at any of the information available online about nutrient contamination of the Chesapeake Bay.

      http://www.fws.gov/chesapeakebay/nutrient.htm [fws.gov]

    • by Krishnoid (984597)

      Well, at least they're cheaper than day rates.

      -Theo, The Cosby Show (and others)

  • How green? (Score:5, Insightful)

    by Smivs (1197859) <smivs@smivsonline.co.uk> on Wednesday August 06, 2008 @12:16PM (#24498317) Homepage Journal

    This sounds like a great idea if it works, but surely producing concrete is a far from 'green' process. I wonder how long the concrete has to be in place to neutralise the polluting effect of manufacturing it in the first place.

  • Exact location (Score:4, Informative)

    by oever (233119) on Wednesday August 06, 2008 @12:20PM (#24498403) Homepage

    The road is here [google.com] according to a Dutch source [nieuwsbank.nl].

    • Ironic.
      I live in, according to various sources, the most air polluted area of the Netherlands. The whole neighborhood is undergoing re-pavement as we speak. And where do they place these tiles?
      Right.. in one of the more greener cities of the country.
      Seems to me it should have been a no-brainer to where to test these tiles.
  • Is industrial development and research at a point now where we don't have to worry about suddenly discovering an airborne carcinogenic byproduct from the reaction in about 10 years?

    If this is both safe and effective, it's a major breakthrough.

  • by Anonymous Coward on Wednesday August 06, 2008 @12:23PM (#24498459)

    The scientists driving around to check their air sampling monitors negates any positive effect produced by the concrete.

  • harmless nitrates ? (Score:5, Informative)

    by cinnamon colbert (732724) on Wednesday August 06, 2008 @12:26PM (#24498515) Journal

    not to mention all the side products that are produced, msot of which i am willing to bet havenot even been identified, much less studied

    J Environ Qual. 2008 Feb 11;37(2):291-5. Print 2008 Mar-Apr.Click here to read Links
            When does nitrate become a risk for humans?
            Powlson DS, Addiscott TM, Benjamin N, Cassman KG, de Kok TM, van Grinsven H, L'Hirondel JL, Avery AA, van Kessel C.

            Soil Science Dep, Rothamsted Research, Harpenden, Herts, UK.

            Is nitrate harmful to humans? Are the current limits for nitrate concentration in drinking water justified by science? There is substantial disagreement among scientists over the interpretation of evidence on the issue. There are two main health issues: the linkage between nitrate and (i) infant methaemoglobinaemia, also known as blue baby syndrome, and (ii) cancers of the digestive tract. The evidence for nitrate as a cause of these serious diseases remains controversial. On one hand there is evidence that shows there is no clear association between nitrate in drinking water and the two main health issues with which it has been linked, and there is even evidence emerging of a possible benefit of nitrate in cardiovascular health. There is also evidence of nitrate intake giving protection against infections such as gastroenteritis. Some scientists suggest that there is sufficient evidence for increasing the permitted concentration of nitrate in drinking water without increasing risks to human health. However, subgroups within a population may be more susceptible than others to the adverse health effects of nitrate. Moreover, individuals with increased rates of endogenous formation of carcinogenic N-nitroso compounds are likely to be susceptible to the development of cancers in the digestive system. Given the lack of consensus, there is an urgent need for a comprehensive, independent study to determine whether the current nitrate limit for drinking water is scientifically justified or whether it could safely

    • >Moreover, individuals with increased rates of endogenous formation of carcinogenic N-nitroso compounds are likely to be susceptible to the development of cancers in the digestive system.

      My memory of organic chemistry is that consumption of nitrites, not nitrates, results in formation of endogenous N-nitroso compounds, but I may be wrong.

    • Well, you'd rather have it in the air?

  • Two problems (Score:3, Insightful)

    by snarfies (115214) on Wednesday August 06, 2008 @12:26PM (#24498517) Homepage

    1) From TFA: "'With one rain shower everything is washed clean,' the institution said in a statement." Ah, but exactly WHAT is washed to WHERE, eh? Are we just trading off air pollution for water pollution?

    2) How durable is this new substance? How much pollution can the road suck up before it wears out? Will it need to be resurfaced and/or replaced every year? Two years?

    • by phorm (591458)

      Sounds to me like the nitrates will accumulate and then be washed away. They in themselves might not be so beneficial in concentrated form, but perhaps if they installed gutters the nitrates could then be used elsewhere. In many cases I believe that nitrates etc are beneficial for enriching plant soil, etc, we just don't want it creating massive amounts of unpleasant algae in the local watersheds.

      • by MightyYar (622222)

        we just don't want it creating massive amounts of unpleasant algae in the local watersheds.

        "From Smog to the Bog"

  • This isn't that new (Score:3, Informative)

    by Devon Dan (1012105) on Wednesday August 06, 2008 @12:27PM (#24498533)
    This stuff isn't that new. It definately has been sold for quite a while under the name TX Active [ http://www.italcementigroup.com/ENG/Media+and+Communication/News/Corporate+events/20060228.htm [italcementigroup.com] ]. They used it to make the Air France head quarters at Charles de Gaulle Airport a few years back. http://www.physorg.com/news67012896.html [physorg.com]
    • by j_snare (220372)

      You know, reading these two kinda puts the article from the summary in perspective. They have even less information about how it works than it does! Still, thanks for finding these, maybe we can find some more information based on the additional information here.

  • by bill_kress (99356) on Wednesday August 06, 2008 @12:31PM (#24498613)

    Maybe we could do even better.

    Hmm, since we're being green anyway, lets eliminate some of the cars--then perhaps we could make the concrete softer to walk on.

    We could use some other color but grey--yuck. Maybe green to represent the fact that it purifies the air.

    Being softer, it would be nice if it had some kind of self-patching mechanism...

    As long as it's going to be self-patching, let's get really sci-fi and have it create itself using some kind of a system involving materials from underneath itself in some kind of a synthesis process.

    Damn, I'm thinking way too far ahead--our science will never get to the point where it can do this stuff. Guess I'll have to be happy with air-purifying concrete.

    • by MightyYar (622222)

      I know you are joking, and it was actually pretty funny...

      But grass makes a terrible surface for any high-traffic area. Look at what they have to do in New York's Central Park just to keep grass on all the lawns. They have to fence off areas, reseed, re-sod, fertilize and poison the holy hell out of everything.

  • Meh... (Score:5, Interesting)

    by Thelasko (1196535) on Wednesday August 06, 2008 @12:33PM (#24498665) Journal
    Chicago is putting in water purifying concrete. [iht.com]
  • for the Beijing Olympics this year.

  • by quanminoan (812306) on Wednesday August 06, 2008 @12:35PM (#24498713)

    I did some research for school over in Hong Kong for a few months and worked with the Hong Kong Polytechnic University Civil Engineering Dep. They used titanium dioxide coatings on bricks and highway noise barriers - actually in use in Hong Kong. They also have attached titanium dioxide nanoparticles to textiles to make filtering clothing:

    http://www.polyu.edu.hk/cpa/polyu/hotnews/details_et.php?year=all&news_id=255 [polyu.edu.hk]

    http://www1.polyu.edu.hk/hotnews/details_e.php?year=all&news_id=964 [polyu.edu.hk]

    It's great to see it catching on...

  • by clone53421 (1310749) on Wednesday August 06, 2008 @12:39PM (#24498783) Journal

    Harmless... [wikipedia.org]

    In freshwater or estuarine systems close to land, nitrate can reach high levels that can potentially cause the death of fish. While nitrate is much less toxic than ammonia or nitrite, levels over 30 ppm of nitrate can inhibit growth, impair the immune system and cause stress in some aquatic species.[citation needed] However, in light of inherent problems with past protocols on acute nitrate toxicity experiments, the extent of nitrate toxicity has been the subject of recent debate.

    In most cases of excess nitrate concentrations in aquatic systems, the primary source is surface runoff from agricultural or landscaped areas which have received excess nitrate fertilizer. These levels of nitrate can also lead to algae blooms, and when nutrients become limiting (such as potassium, phosphate or nitrate) then eutrophication can occur. As well as leading to water anoxia, these blooms may cause other changes to ecosystem function, favouring some groups of organisms over others. Consequently, as nitrates form a component of total dissolved solids, they are widely used as an indicator of water quality.

    What could possibly go wrong, though? It's not like roadways are "surfaces" that might "runoff" into storm sewers or waterways.

    • Harmless... [wikipedia.org]

      What could possibly go wrong, though? It's not like roadways are "surfaces" that might "runoff" into storm sewers or waterways.

      We'll call it Mostly Harmless then.

  • air treatment (Score:3, Interesting)

    by FudRucker (866063) on Wednesday August 06, 2008 @12:43PM (#24498847)
    why not get some crop dusters and fit them to release a fine powder of this air cleaning agent at high altitude above cities that have smog & air pollution problems?

    what will it do to ground water and lakes & rivers? maybe clean them too?
  • What? (Score:2, Insightful)

    by Dunbal (464142)

    As a biologist I take exception to the phrase "harmless nitrates"!

          It may not have anything to do with greenhouse gasses, but more nitrates in rivers and ground-water is the last thing humanity needs.

  • Great. Now the nitrates are washed off by rainwater where it gets into the groundwater. The Dutch already have a significant problem with nitrate polluted groundwater due to farm animal wastes. The country has about 15 million people (versus about 8 million in Georgia) living in an area about a fourth the size of Georgia. They share the land with 4.7 million cattle, 13.4 million pigs, 44 million laying hens, 41 million broilers, and 1.7 million sheep. Altogether, those animals produce three to four times mo
  • The province I live in is currently going nuts over nitrate levels in the groundwater, high levels are a possible cause of cancer and can damage a person's health in other ways too.

  • by GPS Pilot (3683) on Wednesday August 06, 2008 @01:05PM (#24499283)

    the additive binds the nitrogen oxide particles emitted by car exhausts and turns them into harmless nitrates. "With one rain shower everything is washed clean," the institution said

    Hmm... the New York Times says [nytimes.com] nitrates are "a dangerous and increasingly widespread pollutant... reaching dangerous levels in groundwater".

    It seems environmentalists hold wildly diverging opinions on this.

    If the NYT is correct, it's fortunate that this "air purifying concrete" is not likely to be very effective. You see, only a small percentage of the NOx molecules are going to come in contact with the road surface (which makes them eligible for conversion to nitrates). The titanium dioxide in the concrete is not able to reach out and grab NOx molecules floating one meter or even one millimeter above the road. I predict the air quality measurements will show very little difference, and the media will never report on this idea again.

  • by SamP2 (1097897) on Wednesday August 06, 2008 @01:08PM (#24499347)

    Nitrates don't need to be harmless, nor there needs to be zero side effects. All that's needed is that the combined damage produced by any side effects must be less than the damage produced by the excess carbon dioxide in lieu of said concrete.

    Funny how any time there is a proposed innovation to solve a problem, there are always nitpickers who point out side effects without considering their proportion compared to the original problem being solved. A solution either offers a net benefit, or it doesn't.

  • Please educate yourselves before posting dumb comments about nitrates.....

    http://en.wikipedia.org/wiki/Nitrogen_fixation [wikipedia.org]

  • Put this titanium dioxide-based additive in the exhaust systems?
  • old news. (Score:2, Informative)

    by nimbius (983462)
    this has been around since 2002. westminster and japan had it first. its called a noxer block http://en.wikipedia.org/wiki/Noxer_block [wikipedia.org]
  • With the way this concrete works, hopefully it will not get too hot, and make the world's largest Dutch Oven.

    ...

    Okay, even I'm ashamed of that one.. Hehe, Dutch Oven..
  • old news (Score:3, Informative)

    by Goldsmith (561202) on Wednesday August 06, 2008 @02:01PM (#24500175)

    In 1972 it was discovered that titanium dioxide is a strong oxidizer when exposed to light. The following years saw this applied to paints used in hospitals, coatings on windows and building concrete.

    This is old technology which has been in use in Japan for many years. Yes, it does work.

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