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Chemical Engineering In Optimizing WWTP

  • 1.  Chemical Engineering In Optimizing WWTP

    Posted 02-12-2018 08:15
    Dear all,

    I am looking for a methodology on how to optimize the process inside Industrial WWTP.

    How to mitigate the effect of elevation of Ammonia and temperature at the inlet of WWTP.

    Of course, how to prevent the elevation in both

    ---------------------------------
    Aljazi Alshareef
    Environmental engineer
    Petrorabigh
    Jeddah
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  • 2.  RE: Chemical Engineering In Optimizing WWTP

    Posted 02-13-2018 00:21
    Not sure if you have posted this to Water & Wastewater Treatment * r/Wastewater  I realize that is not the most reputable source, but it gets replies reasonably fast. This question is one that many private contractors/companies would likely answer in depth for a fee and even design a full system for your application.

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    Liz Rayfield, E.I.T.
    Utilities and Ecology Process Engineer
    Chevron Oronite
    Belle Chasse, LA
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  • 3.  RE: Chemical Engineering In Optimizing WWTP

    SENIOR MEMBER
    Posted 02-14-2018 00:00
    Hi Aljazi:
    Greetings
    As a former Nalco technologist who has visited PRC WWTP many times and provided detailed report I can state the following:
    NH3 removal is quite easy in conventional activated sludge WWTP of refinery petrochemical complex like your PRC.
    With adequate DO ( 4-6 mg/l), proper pH control 7.5 to 8.0; and optimum biomass control will remove NH3 by nitrification.
    In PRC the IAF regime and the poor DO & pH control with very low biomass produced are the reasons for low NH3 removal. IAF is not well suited for a large WWTP like PRC (850m3/hr) as it cannot provide the required DO for nitrification. Low biomass is generated due to poor BOD removal again due to poor DO and biomass recycle regime.
    Many time the biomass is lost due to shock loading and it takes few weeks to come back to minimum biomass concentration MLSS.
    Your plant needs a complete reengineering of operational mechanical and chemical treatment regime.
    Hope this helps.
    Regards
    Venkat 

    --
    Best Regards
    Venkat Subramanian





  • 4.  RE: Chemical Engineering In Optimizing WWTP

    Posted 02-13-2018 06:37
    Edited by Sathishkumar Santharam 02-13-2018 07:27
    Hello Aljazi,
    I guess we need more information to answer your question.

    1. What kind of industry is this?
    2. How high is the ammonia concentration?
    3.  Do you have a biological activated sludge process in the WWTP?
    4. What is the effluent discharge standard?

    On a high-level, I can suggest the following:
    1. Equalization Tank
    2. Equalization Tank with air spargers to provide evaporative cooling and NH3 stripping. Need pH > 8 for stripping
    3. Oxidation of ammonia in the effluent

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    Sathishkumar Santharam, Ph.D., PE
    Industrial Water/Wastewater Market Principal
    Jacobs Engineering Group, Inc.
    Houston, TX, United States
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  • 5.  RE: Chemical Engineering In Optimizing WWTP

    SENIOR MEMBER
    Posted 02-14-2018 18:13
    It would be helpful to provide some back ground and more clearly state what what problem you are trying to deal with?
    Are you looking for guidance on how to treat high ammonia concentrations in a high temperature wastewater stream? what ranges? they make a difference.
    Is this a new waste stream to an existing treatment system? or are looking for guidance on designing a new WWTP?

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    Karl De Wahl
    Senior Engineer
    University of Minnesota
    Saint Paul MN
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  • 6.  RE: Chemical Engineering In Optimizing WWTP

    SENIOR MEMBER
    Posted 02-15-2018 10:18
    First step, is it possible to isolate and deal with the problem(s) upstream of the WWTP? I once dealt with a process with the same problems of temp and nitrogen. One stream, maybe 15% of the hydraulic load, was 90% of the nitrogen. We were able to pull that stream out and send it to a neighboring plant that was always adding nitrogen for nutrient value. There were operating details and the permitting authorities to deal with but it was a viable solution. Same for the temp. One stream was a stripper bottoms that was the the of the heat load and less than 20% of the hydraulic load. Brute force cooling of that stream was more economical than cooling the entire influent stream.

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    Andrew Steurer
    Ashtabula OH
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  • 7.  RE: Chemical Engineering In Optimizing WWTP

    SENIOR MEMBER
    Posted 03-10-2018 23:02
    To mitigate high ammonia and high temperature in the WWTP influent should be done in the source of wastewater by waste segregation and cooling down of "hot" wastewater prior discharge to the waste water collection system. The segregated concentrated waste with high ammonia content can be sent for offsite disposal, which in most cases is more economical than building an ammonia treatment plant.

    However, if it is not possible to segregate ammonia from the source of waste water; and if ammonia complexes interfer with the wastewater treatment process, then an ammonia treatment plant should be installed as pre-treatment part of WWTP. Conventional ammonia treatment plant is a series of stripping and scrubbing processes. In the scrubber, ammonia is converted into (NH4)HSO4 and is sent for offsite recycling/reuse as fertilizer plant feedstock.

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    Winie Osena
    Senior Process Engineer
    M+W Singapore Pte. Ltd.
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  • 8.  RE: Chemical Engineering In Optimizing WWTP

    SENIOR MEMBER
    Posted 04-11-2018 12:22
    The elevated temperature may be mitigated with a spray cooling pond. -- just a thought.  Look at the carbon to nitrogen ratio at the inlet the conventional water activated sludge unit.  If too much nitrogen- pretreatment or upstream process change may be worthy of consideration.

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    Charles Lipp
    Principal Consultant
    Lake Innovation LLC
    Lake Junaluska NC
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