Applications of Biological Enhancement in Carbon/Sand Filter

Efficiently making use of granular activated carbon (GAC) to reduce pollution is always a golden goal for water industry. We developed ultrasonication collection method for determination of the biomass and microbial attachment and growth in activated carbon filter. Based on this method, we found that using hydraulic cycle to immobilize cells onto GAC can greatly improve the attachment of inoculated microbial cells. The immobilization parameters of immobilization time and flow rate were optimized to assure the dominant growth of inoculated cells on GAC. To keep the consistency of the surrounding biological environment, sand layer and backwash were employed to dilute the locally enriched amino acids and cells due to the inoculation. Although the backwash can cause some cell detachment on GAC, this is of little significance compared with cells staying on GAC. Optimized hydraulic cycle immobilization (HCI) can accelerate the biodegradation process, thus extend the life of GAC, but has little effect on the stability of the surrounding biological environment.