Issues with Ao operation, regarding Sv30 silt drift
Thread Content
This post was last edited by Gorou’s Eight Trigrams Staff on 2015-7-4 at 18:11. The AO process is in use; currently, the Sv30 value is quite high. SVI has not been measured, but it seems high based on visual inspection. Recently, both COD and ammonia nitrogen levels in the water have increased, which has led to an increase in aeration volume. But SV30 is also increasing; now there is a thick layer of sludge floating in the sedimentation tank – is it due to the growth of filamental bacteria? Is it still excessive aeration that causes the sludge flocs to disintegrate? The DO is around 1–4, the inflow volume is about 350 tons, and the return sludge volume is also 350 tons. Should the amount of return sludge be increased to reduce the retention time of sludge in the sedimentation tank?
Increase sludge discharge, control the aeration volume, keeping the dissolved oxygen at 2-3 is sufficient, and increase the internal recirculation flow. Sludge in the sedimentation tank may be carried up by the gases generated during denitrification. Increase the internal reflux ratio. As long as the amount of sludge in the A/O system can be maintained at a certain level, the return sludge is sufficient; for more details, please refer to Environmental Protection - Communication Forum.
Have a microscopic examination done as soon as possible to check the condition of the filaments, which will also help determine the cause.