Biotechnology for the prevention of eutrophication in lake

• Main Author: Goh, Shiao Yen.
• Other Authors: Volodymyr Ivanov
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Environmental engineering::Water supply
• Online Access: http://hdl.handle.net/10356/16333
• Institution: Nanyang Technological University

The application of iron-reducing bacteria (IRB) to phosphate and nitrogen removal from Nanyang Lake water was studied. Ferric ion (Fe3+) from iron ore was reduced by iron-reducing bacteria to ferrous ion (Fe2+) under anaerobic conditions. The formations of soluble ferrous ion (Fe2+) are capable of precipitating phosphate. Meanwhile, ammonium ions (NH4+) are able to be removed by react with ferric ion (Fe3+) and form precipitate which is ferric hydroxide [Fe (OH)3]. 15mg/L of glucose (C6H12O6) was daily added into the influent in order to supply enough inorganic carbon and nutrients for iron-reducing bacteria (IRB). Due to the phosphorus concentration presented in Nanyang Lake water was low and it was easily consumed by the microorganism presented in the system or was precipitated with ferrous ion (Fe2+) in the system. Thus, 1mg/L of potassium dihydrogen orthophosphate (KH2PO4) was daily added to the influent of both systems since day 54 onwards to day 64. Moreover, by adding excess amount of the trigger nutrient - phosphate (PO43-) into the two systems and cause the lake water to be eutrophicated. Thus, perform the continuous treatment of the eutrophicated lake water until stable conditions of the lake water quality will be obtained.