Wastewater Treatment by Using Cascade Technology for Nitrogen Removal

Abstract

Wastewater treatment plants typically remove nutrients (nitrogen and phosphorus) from wastewater because of environmental, public health, or economical concerns. Nutrients stimulate the growth of algae in surface water. Ammonia can be toxic to certain species of fish. The main goal of this research was to obtain the optimum influent distribution flow in achieving nitrogen removal. A pilot-plant activated sludge system was constructed, consisting of two step cascade for removal of carbon and nitrogen. Each step consists of anoxic and oxic zone. Total volume of the reactor equals 111 liter and the volumes ratio between anoxic and oxic compartments could be controlled by internal moving partitions. Synthetic wastewater having the same properties of municipal wastewater was used in all experiments. The influent total flow rate was 6.4 l/h and fed to the pilot plant at distribution percentages of 50/50%, 75/25% and 87.5/12.5% to the 1st and 2nd anoxic zones, respectively. The results for the entire experimental period showed high removal efficiencies of organic matter of 96% as