Secondary removal of chlorophenolic contaminants in water

In this study, several factors important for the design of a water supply treatment system for the removal of trace amounts of organic contaminants by microorganisms in a fixed–film were assessed. This entailed evaluating the effect of seeding with adapted microorganisms on the acclimation time, determining what depth of support material was required for removal of contaminants and observing the effect of hydraulic loading rate on the contaminant removal efficiency by the microorganisms. The study was conducted in the laboratory using sand columns as fixed–film biological reactors. Pentachlorophenol (PCP), 2,4,6 trichlorophenol and 2,4 dichlorophenol were used as the test contaminants. Dechlorinated Philadelphia tap water, which contained concentrations of dissolved organic matter (DOC) in the range of 1 to 4 mg/l, was used as the source water. The DOC of the source water served as a primary substrate for microbial growth in the sand columns. The total concentration of the contaminants added to the source...