Study on the Treatment of Urban Polluted Water by Immobilized Acinetobacter sp. T1 Bacteria

Ammonia removal in urban polluted water and sediments was achieved by immobilized high-efficiency nitrogen-removing bacteria strain Acinetobacter sp. T1 using inorganic carrier materials. Zeolite, activated carbon and diatomite were compared so as to find the best carrier material. The preferred environmental conditions (temperature, pH, rotation speed, fixation time) for immobilizing bacteria T1 were studied and the performance of the immobilized bacteria under optimal condition for ammonia removal were tested by batch scale simulation experiments. Results show that due to its large specific surface area and high zeta potential, more bacteria were fixed onto diatomite. The immobilized bacteria using diatomite as carrier showed higher ammonia nitrogen removal efficiency. The optimal conditions for the immobilization of bacterial T1 were as follows:temperature of 35℃, pH of 8, shaking speed of 90 r·min^-1 and fixation time of 24 h. Aeration-assisted immobilized bacteria experiment group showed highest ammonia removal efficiency during the simulation experiments. After 16 days of reaction, the COD, NH₄⁺-N and TN concentrations in water decreased by 75.98%, 99.32% and 89.36%, respectively. The sediment TOC and TN contents decreased by 54.56% and 44.84%, respectively, and the sediment volume decreased by 14.93%.