Technical modification of denitrification enhancement in T type oxidation ditches

Key words: 
• T type oxidation ditches /
• denitrification /
• modification /
• aeration time

Abstract: Though prolonging aeration time in side ditches, the technical modification of T type oxidation ditches of BOD biodegraded mode in the aspect of denitrification enhancement was constructed. Results proved that, when aeration time in side ditches was increased from 0.5 h to 1 h and radio of denitrification time to nitrification time, tDN/tN ,was changed from 0.56 to 0.50, percentage of nitrification was increased and ability of denitrification of the system was improved. After modification, concentration of NH3-N of outlet, 10.4 mg/L, dramatically lower than before, 15.5 mg/L, met discharged standards of Guangdong Province (DB 44/26-2001), and denitrification efficiency was dramatically enhanced from 52.1% to 68.3%. The problem of high concentration of NH3-N of outlet in wastewater plants was solved. With low investment and high efficiencies, the modification has certain of value of popularization and application.