Question

How can we remove phenolic and aromatic compounds from wastewater?

We are attempting to culture micro algae in industrial waste water. But due to the presence of heavy amount of phenolic compounds, we are unable to grow algae in it as probably it is blocking light to pass through it. However, when we are using the waste water in 10% to 40 % concentration, algae are growing in it .But we want to grow algae in 100% concentration i.e. in the waste water as it is by removing the aromatic and phenolic compounds to enhance the light penetration. Can anyone suggest what is the way out?

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All Answers (12)

  • Albert Torrents Sallent · Barcelona Microelectronics Institute
    I don't know exactly, but if you are looking for biological process to remove phenolic compounds, there are few organisms able to do. Phenolic degradation is almost done by fungus (also aquatic ones) and a very limited set of bacteria.

    Also it's important to know a little about the nature of compounds. Both polyphenols and phenols containing double bound between carbons and heterophenols (i.e. containing N or P in the ring) will be harder to degrade and will require more specialized organisms.

    I had similar issues working with wastewater treatment plants (using wetland tech) for treating winery wastes.
  • Yongjun Zhang · Technische Universität Berlin
    Phenolics have inhibition effects. Therefore, your algae can grow only after dilution. Maybe you can consider some pretreatments to remove the inhibitors, eg, adsorption as suggested by Sven.

    Additionally, other inhibitors may also co-exit with phenolics, e.g., melanoidin in vinasse wastewater.
  • Arghyadeep Gupta · The Energy and Resources Institute
    Thank you Mr Schenk and Mr. Zhang.. Could u name a few more compounds other than PVP which could be used as adsorbents?
  • Arghyadeep Gupta · The Energy and Resources Institute
    Mr Albert ! Thank you so much for your elucidation..Are you trying to grow algae on your microbial pre- treated wastewater?
  • Rodrigo Salazar · Centro Universitário Franciscano (Unifra)
    Dear Gupta,
    I believe that you do a physicochemical pretreatment in order to reduce the toxicity of these compounds. You could test a photocatalytic pre-treatment system (homogeneous catalysis with UV/Fe3+/H2O2 or heterogeneous catalysis with UV/TiO2 or other UV/semiconductor). Have a nice job.
  • Albert Torrents Sallent · Barcelona Microelectronics Institute
    Dear Arghyadeep Gupta,

    I was working over 17 years on natural wastewater treatment plants, so we build aquatic ecosistems and there we grow bacteria and algae as base for a complet food web, raising to aquaculture species and usable waterplants (for feed, composting, artcrafts and so)

    If you are interested you can check some works at www.lagota.cat

    (now I'm not directly working on it, because I'm finishing my microbiology PhD...)
  • Alexandros Stefanakis · Helmholtz-Zentrum für Umweltforschung
    Hi,
    we are running a project on exactly this topic. We use horizontal subsurface flow Constructed Wetlands for the removal of phenolic compounds from contaminated groundwater, aiming at determining the removal performance and investigating the various removal processes, using tools like flow cytometry and isotope fractionation. So far, it seems that biodegradation is the dominant removal mechanism, especially under aerobic conditions. In the next months we will have a better insight on the processes. So, perhaps you could use a wetland system as a pre-treatment stage. What are the concentrations you want to treat? Dont forget that phenols are toxic compounds and very high concentrations might affect algae growth and plants.
  • Samane Ghodraty · Faculty of Medical scinces
    Hi
    The process of adsorption by activated carbon can be appropriate method which can be obtained from various plant sources. Activated carbon has a good capacity for eliminate of different aromatic organic compounds.
  • Sellappan Eswaramoorthi · Anna University of Technology, Tiruchirappalli
    Add equimolar concentrations of Cu2+ and Fe2+ as catalysts along with required H2O2 determined by the quantity of COD that has to be reduced. This shall work fine for phenolic compounds. You can use either homogeneous catalysis or heterogeneous catalysis. In the case of homogeneous catalysis, you have to take care of copper that may enter into the environment after treatment. In the case of heterogeneous catalysis, coat very thin layer of copper on pure iron. Copper coated iron nano particles shall have very good effect. The pH should be around 4.0. If you face any other issues, let me know.
  • Njuguna, G. · Mount Kenya University
    organic pollutants are removed by biological treatment or chemical oxidation methods another method for phenol removal is also used such as adsorption on to granular activated carbon.
    Solvent extraction method is predominantly applied for organic material separation from wastewaters.
    Chemical oxidation by both ozone and chlorine has been reported effective for
    some toxic organics including phenol. It is possible to reach 48 % removal efficiency for phenol at pH 7 and initial phenol concentration of 1000 mg/L using ozone as anoxidant reagent.
    Phenolic compounds, especially chlorinated ones, are similar to herbicides and
    pesticides in structure and they are difficult to remove by biological treatment processes because of their resistance of biodegradation. For me I think chemical oxidation is the best compared to biological method.

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