Probe into start-up methods and optimum running parameters of upflow aerobic filters in winter

Key words: 
• aerobic filters /
• start-up /
• secondary effluent /
• advanced treatment

Abstract: Aerobic filters have the advantages of both common filters and biological aerated filter. The COD, ammonia nitrogen and turbidity of secondary effluent can be farther removed by aerated filter and the reclaimed water qualities are improved. The tests discussed start-up methods and optimum running parameters of aerobic filters in winter. The results are as follows: incremental flowrate can accelerate the start-up of the aerated filters, 1 m/h as upflow rate, (1～3)∶1 as water gas ratio, the filter bed depth relates to filter material size, backwashing when the effluent headloss goes up 1m and the filter can be regenerated in 4 hours. The start-up time was prolonged at low temperature, but the media of filter were covered with stable biofilm. The filter flowrate is confirmed by lab experiment in winter to ensure effluent quality.