Spock
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Ferric Ammonium Citrate Disposal
I have 150 ml of ferric ammonium citrate solution that I need to dispose of. It's grown mold and I need to head back to school for the semester. I'd
prefer to avoid dumping it straight down a drain as it's toxic to fish. I'm thinking to add sufficient sodium hydroxide to precipitate all the iron
out as Fe(OH)3, which being rust, shouldn't be any issue to dispose of. Does this seem like a reasonable disposal method?
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phlogiston
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You don't mention the concentration.
I don't think you need to be overly worried about its toxicity to aquatic life. All of the ions in solution are common in the environment already,
except citrate, but that too will be easily and quickly broken down by microorganisms in the environment. Iron salts are used on a large scale to
fertilise plants. Our local gardening store sells multi-kilogram bags of iron salts for the garden.
If you really want, you could do as you propose, but you should expect some ammonia gas to evolve as well, especially if you add an excess of
hydroxide. Do it outside when there is some wind.
Furthermore, the iron hydroxide precipitate will form a gel, not a clean powder. If you were planning to remove it by filtration, it will take very
long.
[Edited on 13-1-2019 by phlogiston]
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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unionised
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The purpose of the citrate in the compound is to keep the iron in solution as a complex.
One way to dispose of it would be to put it into a soft drink.
https://en.wikipedia.org/wiki/Irn-Bru
The mold might be a bigger hazard than the ferric ammonium citrate.
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CharlieA
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Isn't rust ferric oxide, not ferric hydroxide?
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j_sum1
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Rust is a pretty generic term for mixed iron oxides and hydroxides and complexes.
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DavidJR
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Just pour it down the drain. Honestly, it's pretty innocuous stuff.
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woelen
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Indeed, just down the drain with it, or flush it away in the toilet.
Iron(III) is not an issue at all, it is a very common ion in nature.
Citrate also is common, in tropical regions it is present in all kinds of fruits.
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MrHomeScientist
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I usually take "rust" to mean red iron oxide, Fe2O3. But actual rust is probably a complex mixture of oxides, hydroxides, and
carbonates.
The way I think about disposal is get your chemicals into the least soluble form possible, then dispose in regular trash. This goes to an incinerator,
which will calcine everything into even less soluble forms. So your iron hydroxide, for example, would burn into iron oxide anyway.
There are exceptions, of course. Don't throw away arsenic or mercury 
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DavidJR
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Quote: Originally posted by MrHomeScientist  | I usually take "rust" to mean red iron oxide, Fe2O3. But actual rust is probably a complex mixture of oxides, hydroxides, and
carbonates.
The way I think about disposal is get your chemicals into the least soluble form possible, then dispose in regular trash. This goes to an incinerator,
which will calcine everything into even less soluble forms. So your iron hydroxide, for example, would burn into iron oxide anyway.
There are exceptions, of course. Don't throw away arsenic or mercury
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Since when is 'regular trash' incinerated?
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fusso
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I had threw some solution containing Fe3+ and oxalate down the drain too, no worries.
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MrHomeScientist
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| Quote: Originally posted by DavidJR | | Quote: Originally posted by MrHomeScientist | I usually take "rust" to mean red iron oxide, Fe2O3. But actual rust is probably a complex mixture of oxides, hydroxides, and
carbonates.
The way I think about disposal is get your chemicals into the least soluble form possible, then dispose in regular trash. This goes to an incinerator,
which will calcine everything into even less soluble forms. So your iron hydroxide, for example, would burn into iron oxide anyway.
There are exceptions, of course. Don't throw away arsenic or mercury
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Since when is 'regular trash' incinerated? |
It is here. It's how our area handles "recycling," through a Waste-To-Energy (WTE) facility. An excerpt from one of their emails:
| Quote: | A WTE facility, unlike an incinerator which just burns waste, extracts energy from the waste. A WTE facility is basically an electrical power plant
that utilizes waste as a fuel source, versus coal or natural gas. With over 500 facilities, WTE facilities are fairly common in Europe. In the United
States, which only has 71 WTE facilities, they are still somewhat of a rarity. In the County, almost all of the combustible household and commercial
waste is processed at the WTE facility and is converted into electrical energy.
In addition to the electrical power generated from the combustion process, all of the metals, both ferrous and non-ferrous, are extracted from the ash
residue and recycled.
As a general rule, unless the WTE facility is inoperable or is operating above rated capacity, the County landfill is only used as a repository for
the ash residue left over from the combustion process or for the disposal of non-burnable materials that cannot be processed at the WTE. This
dramatically increases the life of the landfill. The County landfill was opened in 1987 and was expected to reach capacity in 2019. Because of the
operation of the WTE facility, the last landfill life estimate extends the date that the landfill is expected to reach capacity out to 2047.
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Pretty cool stuff, really. I assumed that other areas had incinerators at least, if not WTE facilities. You should of course consider your own area's
local waste handling procedures to inform your own personal ones.
[Edited on 1-15-2019 by MrHomeScientist]
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fusso
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Oops sorry, deleted.
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j_sum1
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Thanks for looking after that, fusso. Gracious of you.
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