Coal Bottom Ash as a Biofilter for Water Organic Contaminants

Haim Katz, Biological Chemistry, University of Ariel, Ariel, Israel
Yaakov Anker, Research and Development Center of Samaria and the Jordan Valley, Ariel, Israel
Rivka Cahan, Chemical Engineering, University of Ariel, Ariel, Israel
Haim Cohen, Biological Chemistry, University of Ariel, Ariel, Israel

Petroleum compounds are major contamination source of industrial wastewater and ground water and can be treated by several physico-chemical approaches to decontaminate those pollutants like adsorption and different oxidation reactions.

Bioremediation of hydrophobic contaminants are also a possible mode of treatment.

We have developed a bio-filter, based on bottom coal ash as carrier for specialized bacterial colonies (biofilm) at petroleum contaminants degradation in which toluene has been chosen as the model compound.

Bottom coal ash aggregate, is a byproduct of coal burning in the Israel Electricity Company utilities.

Pseudomonas putida, which is well known as toluene degrading bacterium has been grown on the bottom ash to produce a biofilm which serves as the cleaning reagent for the toluene.  SDS (Sodium Dodecyl Sulfate – cmc {critical micelle concentration} = 2,340 mg/L) and the biosurfactant is Rhamnolipid (cmc = 60 mg/L) have been used as the Rhamnolipid is bioactive at very low concentrations (as a result of his low cmc).

The results indicate that the biofilm is efficient toluene biodegradation (in 24 hours period, 69-96% of the toluene was degraded). 

Keywords: coal ash, toluene biodegradation, bio-filter