Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Related Articles


How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

Hi everybody,

The disinfectant N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine is present in the wastewater I want to treat through an active sludge system.

I'm searching for a way to deactivate it to enable bacteria growth. I know it is a polyamine, a weak base, a non ionique surfactant and a bactericide.

I can't use an oxydant or an acid to degrade it because of the organic matter of wastewater.

If you have an idea, I will be very grateful.

If you want to see the molecule

RE: How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

What concentration are you working with and do you have an easy measurement method?

"Any water can be made potable if you filter it through enough money"

RE: How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

You could try hydrogen peroxide to oxidise it or perhaps a UV/peroxide combination.
But i woulde be tempted to try to acclimatise a batch process activated sludge to treat it. If you can measure the concentration easily you could start out with a lab scale plant treating just a few litres perhaps using raw sewage as a feed source if the N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine solution is otherwise nutrient deficient.
Acclimatisation will probably be at least 2 SRT (solid retention time) but may be much longer.

"Any water can be made potable if you filter it through enough money"

RE: How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

Hi ashtree,

Thanks for your advice.

I have not made the wastewater analysis yet. However my calculations gave me a concentration between 34 and 61 mg/L.
The original solution has a concentration of 24 g/L. The purchaser recommend to use a diluted solution between 0.1% and 3%. It means between 24 mg/L and 720 mg/L.

Do you think the bacteria of the sludge has a chance to treat it ? I will try in a lab as you said but the concentration seems pretty high... I should maybe design the biologic reactor sufficiently big to dilute it below the 24 mg/L ...

I don't think UV oxidation will be possible because of the turbidity of the water.

About the hydrogen peroxyde, I'm afraid the organic matter of the sewage will be oxidised before the molecule.


RE: How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

More questions.

Is the N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine already mixed in with other wastewater or is it in a stream of its own? Why i ask is that would it be possible to treat this stream with ozone or peroxide or UV before mixing with anything else.

Where does this wastewater ultimately go and is there any limits set for N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine or subsequent breakdown products?

What happens to your waste sludge stream?

What are the volumes that we are dealing because if it is only small and or irregular you might be better to use another option all together?

Obviously a lower concentration is better as the disisnfectant will impact on the activated sludge system particularly for a start. If you can acclimatise the sludge to handle it then you may be able to gradually increase the concentration. A large reactor will be beneficial in that it will offer a longer detention time and allow very slow reaction rates.

Of course it may not be possible to achieve any useful reduction in concentrations at all, reaction rates may be very slow, or the breakdown products just as problematic.

"Any water can be made potable if you filter it through enough money"

RE: How to deactivate N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine ?

This product appears to be readily biodegradable and should be treatable with the activated sludge system.


Where does the treatability concern originate?

Before investigating advanced treatment steps such as oxidation, it would be worthwhile to have a professional consultant run a bench scale activated sludge test.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


White Paper: Industrial Control Basics: Contactors
A contactor is an electrical device used for switching an electrical circuit on or off. Considered to be a special type of relay, contactors are used in applications with higher current carrying capacity, while relays are used for lower current applications. Download Now
Research Report: State of IoT Adoption in Product Development 2019
This research report, based on a survey of 234 product development professionals, examines the current state of Internet of Things (IoT) adoption by product design teams, its perceived importance, and what features and capabilities teams consider important when making decision about adding IoT functionality to their products. Download Now
Research Report: Augmented Reality for Maintenance, Repair and Overhaul (MRO)
The term Industry 4.0 denotes a cluster of technologies that’s poised to fundamentally reshape manufacturing and bring about a new industrial revolution. These include 3D printing (AM), the Industrial Internet of Things (IIoT), artificial intelligence (AI) and mixed reality technologies, more commonly known as virtual reality (VR) and augmented reality (AR). Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close