Application of Emergency Dosing Chemical to Remove Ammonia Nitrogen in a Sewage Treatment Plant

A county sewage treatment plant located in Hebei Province was seriously damaged,due to impact of industrial wastewater. The NH3-N concentration of the effluent was high and couldnot meet the national first level A standard. Emergency treatment of dosing the self-developed chemical was thereby adopted to restore the sewage treatment plant to normal. The lab-scale test results showed that the effluent NH3-N could be reduced from 25 mg/L to less than 5 mg/L under reagent mass ratio of 0. 025% and reaction time of 10 min,and the method had no adverse effects on the other effluent indexes. The full-scale test results showed that the effluent NH3-N and TN concentrations were 2. 55-3. 25 mg/L and 8. 38-9. 63 mg/L after dosing the self-developed chemical,which stably reached the national first level A standard.