Anonymous asked in Science & MathematicsChemistry · 4 months ago

How do you dispose of sulphuric acid drain cleaner?

I have strong sulphuric acid drain cleaner at home, which I no longer need.

How do I dispose of it safely?


10 Answers

  • 4 months ago
    Favorite Answer

    extreme dilution is probably the easiest way (does not really get rid of the acidity but it makes it weaker so less of a problem).  Neutralization with a base is probably the most effective way, but the reaction might be vigorous so you have to be very careful.

    Oh, and don't forget: do as you oughter, add acid to water.

  • david
    Lv 7
    4 months ago

    You probably have a quart (~1 liter) or less so safe disposal should be very easy.   ---  put 2 times that volume of water into a bucket -- into the water, now add the acid to dilute it.  Now get a few pieces of gravel and add carefully to the bucket.  Gravel is basically calcium carbonate.  It will 'bubble' as it reacts.

         CaCO3  +  H2SO4  -->  CaSO4  +  H2O + CO2(g)

    if all the gravel disappears, add more gravel.  

    When the bubbling stops and there is extra gravel left, then it is safe to pour it anywhere .. if you pour down a drain, be careful to not let any gravel go down the drain.

  • 4 months ago

    Being an acid your dilute it in the extreme.  Pour the acid into a large quantity of water. Then pour the resultant solution into more water . 

     However, remember all carbonates react with acids.  So if you have chalk (CaCO3) or, washing Soda (Na2CO3) or Baking Powder (NaHCO3) , they will all react with sulphuric acid forming the sulphate salt, water and carbon dioxide. Hence the acid is disposed. 

  • Mike A
    Lv 7
    4 months ago

    It is produced to pour down the drain. Although you refer to it as "strong" it is only likely to be 60% by weight so dilution will not present too much of a problem. We all can find a dirty drain somewhere so use it.

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  • 4 months ago

    Pour acid into water, NEVER water into acid.

    Concentrated sulfuric acid has a big heat of dilution; if you pour water into con sulfuric it can boil and spatter con sulfuric on you.

    Dilute the acid then add baking soda until it stops fizzing. Excess baking soda will not hurt.

    It is legal under RCRA to neutralize waste that is hazardous only by reason of pH then discharge it to a sewer. So doing as I direct would be legal for a business, as well as environmentally sound for a home.

    Do not use lime as that will make calcium sulfate, aka gypsum or plaster, which could plug your drains. Sodium sulfate is very soluble.

    Source(s): chemical engineer, did a lot of environmental compliance work
  • 4 months ago

    See if your state has an agency that handles hazardous waste. 

  • Anonymous
    4 months ago

    Follow disposal instructions which should be on the container.  If there are none, do this:

    Carefully/slowly pour a small portion of acid into a bucket half-filled with water. while stirring (e.g with old stick).  Pour mixture down drain.  Repeat till container is empty.

    Do NOT add water to acid as heat is generated and the mixture can boil/spit.  This means being very careful when you rinse out the container. (You could immerse the empty contsiner into a bucket full of water.)

    Rinse out bucket.

    Avoid splashing. Use eye protection/gloves if you want to err on the safe side.

  • ?
    Lv 7
    4 months ago

    Mix it with a strong base compound to neutralise it

  • 4 months ago

    Put it down the various drains & toilets in small batches followed by plenty of water!

    That is where it is intended to be used & it will do no harm - just avoid contact with metal surfaces or plating and use protective gloves & glasses etc. while handling it or flushing it away.

  • 4 months ago

    read the label, there should be directions there. 

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