Treating Water with High Levels of Organics

By definition:

Low fouling water: (TOC <2% total anions)

Moderate fouling water (TOC = 2 - 5% total anions)

High Fouling water (TOC >5% total anions)

Another test for measuring organics in water is COD = Chemical Oxygen Demand which is a test that oxidizes organics in water using Di-chromate. VOC's = volatile organic compounds are another category or organic pollutants that are volatile. Some common VOC's are BTEX = Benzne, Toluene, Ethylbenzene and Xylene which are petroleum products.

Removing organics from water can be done using several technologies depending on the nature of the organic pollutant:

1. Coagulation and Flocculation (if the organic pollutants are coagulable) and this treatment methodology can be supplemented by using PAC

2. Activated Carbon Filtration using GAC

3. Advanced Oxidation Processes: using UV light and oxidants such as Fenton's Reagent. This tecnique is also used for removing VOC from polluted soils

4. WBA Ion Exchange resins

5. Specialized organic trap resins

6. Using Chromatographic Columns in Normal Phase or Reverse Phase (Lab Scale).

7. If the organics are immiscible fluids like kerosene or benzene or diesel, then oil separators can be used

8. RECAM from SA Envitech is a material based on graphene with very exciting properties for water treatment

9. Biological degradation (if the organics are biodegradable). Ofcourse genetic engineering allows the development of custom bacteria that degrade even persistant organica pollutants.

10. Demulsifiers: if the organic pollutant is in the form of an emulsion, then an emulsion breaker can be used

11. Reverse Osmosis technology can be used to reject large size organic molecules from water

12. Ozone can be used to oxidize some organics


Compiled by Rami E. Kremesti M.Sc.