Wastewater from acrylonitrile process deal by activated sludge

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Dear all,

The wastewater comes from the acrylonitrile process is not easy to deal by activated sludge , because the wastewater contains nitrile, biological toxicity, and that is not suited for microbial to treat the wastewater.
1.If we separate the cyanic acid and acetonitrile from the acrylonitrile process, will the wastewater be good enough to treat by microbial ?
2.is there any way to check the biological toxicity of wastewater is lower, and is suit for activated sludge to treat?

 

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7 Answers

  1. Only 1 way to handle thid troble , Must be separate bath waste out of continue waste then you can do biological treatment. The pretreament by redox process is an important for this wastewater. Could you give me more detail for existing process diagram.

    1 Comment

    1. 1.the ​wastewater flow ​rate from ​acrylonitrile ​process  ​is 1,300 M3/D ​

      2.the ​volume ​of activated ​​sludge ​​treatment ​ is ​5,000 M3, but ​the wastewater ​contain 1,300 ​M3/D from ​acrylonitrile ​process and 2,​700 M3/D from ​epichlorohydrin ​process. ​

      3.the COD of ​inflow is 1,800 ​ppm, the COD of ​effluent is 70 ​ppm, the ​reduction rate ​is 96%. ​

      4.the Temp. ​of acrylonitrile ​process ​wastewater ​could be near ​40 oC. ​

      5.we wish the ​1,300 M3/D ​acrylonitrile ​process ​wastewater can ​be dilute and ​treat in ​another ​​activated ​​sludge ​​treatment ​​process, and ​this process , ​MBR system, ​could be the ​equipment for wastewater reuse.

  2. Hi 

     

    What is the flow rate , can you please specify 

    1. Do you have an activated sludge treatment process in place. 

     

    2. Can you share the analysis of the waste water. 

    3. What is the temperature of the incoming waste . 

    4. what results you are looking for? 

     

    Based on your response a proper workable option can be proposed. 

     

     

    1 Comment

    1. 1.the wastewater flow rate from acrylonitrile process  is 1,300 M3/D

      2.the ​volume of activated ​sludge ​treatment ​ is 5,000 M3, but the wastewater contain 1,300 M3/D from acrylonitrile process and 2,700 M3/D from epichlorohydrin process.

      3.the COD of inflow is 1,800 ppm, the COD of effluent is 70 ppm, the reduction rate is 96%.

      4.the Temp. of acrylonitrile process wastewater could be near 40 oC.

      5.we wish the 1,300 M3/D acrylonitrile process wastewater can be dilute and treat in another ​activated ​sludge ​treatment ​process, and this process , MBR system, could be the equipment for wastewater reuse.

  4. Dear Lin jYH-YAN ,

    The concentration of acrylonitrile in wastewater upon admission to biological treatment should not exceed 20 mg / L.
    The choice of treatment method depends on the composition of the wastewater,  its quantity and cost of methods.
    I think that it is best  you to test the adsorption method with a carbon-mineral sorbent, which can be regenerated many times. My email: ekologijosekspertas@gmail.com:
    Best regards,
    Chemist ecologist Vitalijus Gediminas (Vilnius, Lithuania, EU).

    1 Comment

  5. Acrylonitrile effluents contain also  by activated sludge process non degradable heterocyclic compound pyrazol, up to 500 mg/L . We succeeded to solve the problem via adapted biofilms fixed on special biocarriers.

    2 Comments

    1. Consider the risk of killing off your custom grown fixed film bugs.  If you surge or have a toxic event, then getting them back and acclimated could take several weeks to get it back.  Better have some storage.  If you use an AOP, then you are talking about hours to a couple of days to that a system may be down, and you immediately return to making quality effluent if it is followed by regular AS.  Just think of the risk if you have a “variable” process and get hit with a critical to quality event.  Happy that the other process is working well, but just consider the risk versus reward and ask yourself how lucky do you feel?  Best of luck, my friend.  Sean L Roop

    2. we plan to dilute the Acrylonitrile effluents with others, and the proportion will lower than 10%, is that work in your view?
       

      1 Comment reply

      1. Dear Lin, Hi. Dilution a waste by another does not seem to be useful since maybe there is a conflict in choosing methods. In Cyanide in your waste, for instance, you can remove it with AOP and the Oxygen leftovers may help you for the Acrylonitrile part. I suggest that you can do the dilution process with the outlet water comes out of the WW treating system. Please consider that if you over dilute the waste maybe your sensors (such as ORP electrodes) can`t sense the small number of specific pollutions.

        Good Luck

  6. Acrylonitrile can be degraded easily with ozonation and O3/H2O2 advanced oxidation process. Perhaps you may want to to consider applying either of two processes before going to activated sludge.

    a.amiri@cogeco.ca