Attached-growth system for nitrification at low temperature

Sun, Zhe. M.S.E., Purdue University, May 2014. Attached-Growth System for Nitrification at Low Temperature. Major Professor: Ernest R. Blatchley III. Lagoon systems are commonly used in small communities for domestic wastewater treatment. These systems are simple and economical to operate, and are often appropriate for use in areas where land costs are low. Lagoons are effective in removing conventional pollutants under warm-weather conditions; however, biochemical nitrification is hindered in suspended-growth lagoons during periods of extended cold weather. Attached-growth nitrification systems, as compared to suspended-growth systems, have been reported to yield improved biochemical nitrification under cold-weather conditions. In this work we investigated a new type of biochemical nitrification reactor (i.e., BOBBER) that includes increased surface areas to promote development of attached-growth nitrifying communities has applied to an aerobic lagoon system at Wingate, IN. Results of monitoring of this system have indicated improvements in oxidation of ammonia-N, especially during winter months. To examine the behavior of this system in a more controlled setting, two laboratoryscale mini-BOBBER systems were installed in a temperature-controlled room. The systems were treated with an ammonium chloride feed solution, and allowed to approach steady-state conditions at 20 °C, 15 °C, 10 °C, and 5 °C. In addition, a series of batch