Wastewater treatment process and worm reactor (2)

(3) Optimization of operating operating parameters to improve the stability of sludge reduction T.
1.
G.
Hendrickx used batch experiments (Figure 9-5) to investigate the effect of operating conditions such as dissolved oxygen (DO) concentration and temperature on the reduction of L.
variegatus.
The impact of the amount of sludge
.

The results show that the oxygen transfer efficiency is higher when the DO concentration is 1 ~ 2.

Domestic scholars have investigated the effects of sludge settlement ratio and half-settlement time t50 on the volume reduction of earthworm sludge through batch settlement experiments
.

The results show that the sludge settling ratio (SV, also known as 30min sedimentation rate) of the activated sludge itself and the half-settlement time t _{50, which} characterizes the speed of sludge sedimentation, are the factors that affect the sludge volume reduction effect of the earthworm sludge.

For the first time, a domestic researcher proposed that operating parameters would affect the fixation of worms.
They pointed out that the frequency of high-intensity aeration (FHIA) and the concentration of dissolved oxygen (DO) have complex effects on the fixation of earthworms and the effect of sludge reduction.
The two stages of an operation cycle of the new static shaking earthworm reactor (SSBWR) shown in 9-6
.

The biggest difference between SSBWR and previous researchers is that the carrier uses a perforated plate to install polyethylene fillers to attach the earthworms, the aeration uses a combination of continuous aeration and intermittent aeration, and the volume of the earthworm reactor is a pilot scale (100L).

However, during the reduction process, it was found that the worms ingested the sludge to release ammonia nitrogen.
Therefore, the effluent from the worm reactor must be returned to the sewage treatment system for denitrification, which caused an increase in ammonia nitrogen of the sewage treatment system by about 5% (pH 7.
3~7.
8) , The hydraulic load increases by about 5% to 15%
.

The increase in ammonia affects denitrification, because it means that additional carbon sources need to be added.

For the earthworm (earthworm Aisheng earthworm) biological filter, the reduction effect of earthworm sludge is best at 23～28℃
.

The earthworm biofilter with quartz sand and ceramsite as the carrier has a sludge reduction rate of 38.

Related links: Wastewater treatment process and worm reactor (1)