[peppercorn (OP)]

Hungary battles to stem torrent of toxic sludge

http://www.bbc.co.uk/news/world-europe-11475361

The torrent of toxic red sludge is a by-product of Bauxite mining and is heavily loaded with Iron Oxide.
It is already polluting major waterways and could get into the River Danube.

I wondered how people (as well as ecology) will be effected by this highly caustic sludge?

[tommya300]

Long Range effects, may be camouflaged by some other stressful event.

Gulf oil spill, now this spill, all the terrorist need to do is just sit back the world will crumble from all these other events.
 The margin of error academic publications/engineering guesstimating handbooks need to be upgraded.
Waste reservoirs should be limited to a small quantity.
 When this quantity is being neared production stops, the waste toxitity needs to be neutralized and the safe removal of the substance needs to be handled before any other production is to be continued.

[Bored chemist]

The lagoons are a waste treatment system; they let water evaporate so there's less of the stuff to deal with and they let the caustic absorb CO2 from the air, converting it to the less hazardous sodium carbonate.

Obviously, it's a problem when they go wrong- the same as for any industrial process.

[peppercorn (OP)]

The scale of this man-made 'flood' is just staggering.
I wondered about how villagers who were not drowned but stayed trapped, waist-deep in sludge for 6 hours or more, will fair in the longer term.

The lagoons are a waste treatment system; they let water evaporate so there's less of the stuff to deal with and they let the caustic absorb CO2 from the air, converting it to the less hazardous sodium carbonate.

Does that make this stage of the 'Al' process a CO2 sink then?

[imatfaal]

The margin of error academic publications/engineering guesstimating handbooks need to be upgraded.

Tommy - my experience in the shipping industry is that the margins of error and acceptable tolerances would be fine if the spirit in which they were used was good and risk averse.  However tolerances are often used to make commercial savings.  As an example - the tolerance for steel thickness in shipbuilding used to be very generous because manufacturing processes were not accurate enough.  However, those steel processes are now computer controlled to a high degree of precision - and the steel is now made to within a few fractions of a millimetre of the desired thickness.  The problem arises in that the steel is now specced at damn close to the minimum rather than at the recommended thickness in the knowledge that the sophisticated processes can deliver within the tolerance.  The saving in cost is significant (steel is charged per metric tonne) and the rules adhered to; but it is quite clear that spirit is wrong and potentially weak ships ply the ocean waves.

[Mazurka]

I understand that the nomimnal volume of the lagoon was about 1 million cubic metres - and that around 700,000 escaped making it bigger than than the last big waste dam failure in Europe (Aural Gold mine at Baia Mare in Romania) and comparable to the Merriespruit disaster in South Africa - although both of these were cyanide rich wastes.

The effects of Baia Mare spillage are still discernable 10 years later.  The effects will depend on the throughness of the clean up - and I guess how extensive this is will emerge in coming weeks.

I also understand that the dams at this and 2 other sites retaining the remaining 40-50 million cube of similar slurry are being undergoing emergency strengthening works at the moment

[LeeE]

I think this event, whilst undoubtedly tragic for those concerned, is being a little hyped by the media.  As dam failures (and related accidents) go (and they're a lot more frequent than many might think - have a look at http://en.wikipedia.org/wiki/Dam_failure for a list of dam failures and related accidents) this one wasn't one of the biggest and hardly "staggering".

For info

...and is heavily loaded with Iron Oxide

means that there's a lot of rust in it, which is not regarded as toxic.  This is not to say that the sludge isn't toxic, but the toxicity is not due to the Iron Oxide content.

And re

all the terrorist need to do is just sit back the world will crumble from all these other events

...WTF bring terrorism into it?  What has terrorism to do with any of this?

[tommya300]

The margin of error academic publications/engineering guesstimating handbooks need to be upgraded.

Tommy - my experience in the shipping industry is that the margins of error and acceptable tolerances would be fine if the spirit in which they were used was good and risk averse.  However tolerances are often used to make commercial savings.  As an example - the tolerance for steel thickness in shipbuilding used to be very generous because manufacturing processes were not accurate enough.  However, those steel processes are now computer controlled to a high degree of precision - and the steel is now made to within a few fractions of a millimetre of the desired thickness.  The problem arises in that the steel is now specced at damn close to the minimum rather than at the recommended thickness in the knowledge that the sophisticated processes can deliver within the tolerance.  The saving in cost is significant (steel is charged per metric tonne) and the rules adhered to; but it is quite clear that spirit is wrong and potentially weak ships ply the ocean waves.

I seen a documentry about a Steel cable bridge being built. The thing stuck in my mind about the tolerance of the cable design. The specifications were grossly "Over Designed" with no intention. It was found later the that the lotment of cable manufacture at a later date was altered by the manufacture, reducing the specification. This was not a purchased request, yep a ripoff. Since the original spec was so over killed it did not make a difference, since the find was after the fact it was being used already. Safety was not an issue.

Savings in some cases at the expence to others can be a flip of a coin.

[tommya300]

I think this event, whilst undoubtedly tragic for those concerned, is being a little hyped by the media.  As dam failures (and related accidents) go (and they're a lot more frequent than many might think - have a look at http://en.wikipedia.org/wiki/Dam_failure for a list of dam failures and related accidents) this one wasn't one of the biggest and hardly "staggering".

For info

...and is heavily loaded with Iron Oxide

means that there's a lot of rust in it, which is not regarded as toxic.  This is not to say that the sludge isn't toxic, but the toxicity is not due to the Iron Oxide content.

And re

all the terrorist need to do is just sit back the world will crumble from all these other events

...WTF bring terrorism into it?  What has terrorism to do with any of this?

Terror nothing, slap me,  just relating disasters and the need not to have to exert any outside force to create them we will impose it on ourself.