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OzIA · 03/04/2018, 07:10 PM

On Thursday I noticed the water on the inlet side had increased about 1.5 inches above the level it was before I started the system up. This restriction came much sooner than I anticipated. As a result, I decreased the dose substantially to about 25% of what I had been dosing. I also triggered a manual flush & stir, which did little to reduce the water level. I then added a stir during each batch and cut out all carbon doses except for one that occurs after each batch has settled in the bioreactor. This reduced the level that the ORP was topping out after each batch by about 50 mV. I assume because I was dosing sooner and more consistently after the batch. The water level hasn't increased since Thursday. If it holds where it is, I should be OK.

I also set up an automatic flush and stir to occur each day at 2:00 in the afternoon. The reason I selected this time was that it typically has the highest pH of the day and the flush tends to drive pH down because the bioreactor pH runs around 7.5.

I had to remove about a gallon of bioballs. They were so tightly packed that entire group moved with the arms, as one mass, in the cylinder. There was very little mixing or agitation occurring. With some removed, the space allowed the majority of them to float and then the arms could move through them instead of with them. This also reduced the torque.

On Sunday, I monitored the ORP readings every 30 seconds, by hand; to get a better picture than the Apex Fusion is providing. The result seems to indicate that the de-nitrification is occurring at a much lower ORP then I was achieving so I lowered the target to around -130 mV. I will let the system cycle for a few days with these new parameters and let things stabilize before making any more changes. It takes about two hours after the flush cycle before the bioreactor recovers back to the trigger point of -130 mV. At this point, I am not sure if there is anything I can do to make it recycle faster. I have a few things I can try. First, I may use a larger dose of carbon at the end of the flush cycle in order to get the biofilm active and growing again.

The first batch after the flush reacts very differently than the others. The ORP doesn’t rise above zero and quickly recovers to the trigger point in short order, triggering a second batch within about 10 to 15 minutes. Things eventually work their way back to about 30 minutes per batch / cycle.

During the flush cycles I can see bits of biomatt being dislodged; washed out by the flow and gathered up by the CFC. Also, the CFC is running about twice as much felt as the previous system; about an inch an hour. This will cut my roll life down to about 70 to 75 days. This is about half the roll life I was getting prior to switching out the Version 2 for the V3 sump.

One other noteworthy mentionable is that I was seeing a lot of foam generated by the bubble diffusers. The overflow / air escape was located toward the return pump section so there was no leakage but there was a layer of foam there and the overflow hole would burp out more every few seconds. This decreased when I reduced the carbon dosing. I supposed if I wanted, I could cut a new hole on the opposite side and collect / export the foam like a built-in skimmer.

03/04/2018, 07:10 PM	#20
OzIA Registered Member Join Date: Sep 2016 Posts: 214	Sunday update On Thursday I noticed the water on the inlet side had increased about 1.5 inches above the level it was before I started the system up. This restriction came much sooner than I anticipated. As a result, I decreased the dose substantially to about 25% of what I had been dosing. I also triggered a manual flush & stir, which did little to reduce the water level. I then added a stir during each batch and cut out all carbon doses except for one that occurs after each batch has settled in the bioreactor. This reduced the level that the ORP was topping out after each batch by about 50 mV. I assume because I was dosing sooner and more consistently after the batch. The water level hasn't increased since Thursday. If it holds where it is, I should be OK. I also set up an automatic flush and stir to occur each day at 2:00 in the afternoon. The reason I selected this time was that it typically has the highest pH of the day and the flush tends to drive pH down because the bioreactor pH runs around 7.5. I had to remove about a gallon of bioballs. They were so tightly packed that entire group moved with the arms, as one mass, in the cylinder. There was very little mixing or agitation occurring. With some removed, the space allowed the majority of them to float and then the arms could move through them instead of with them. This also reduced the torque. On Sunday, I monitored the ORP readings every 30 seconds, by hand; to get a better picture than the Apex Fusion is providing. The result seems to indicate that the de-nitrification is occurring at a much lower ORP then I was achieving so I lowered the target to around -130 mV. I will let the system cycle for a few days with these new parameters and let things stabilize before making any more changes. It takes about two hours after the flush cycle before the bioreactor recovers back to the trigger point of -130 mV. At this point, I am not sure if there is anything I can do to make it recycle faster. I have a few things I can try. First, I may use a larger dose of carbon at the end of the flush cycle in order to get the biofilm active and growing again. The first batch after the flush reacts very differently than the others. The ORP doesn’t rise above zero and quickly recovers to the trigger point in short order, triggering a second batch within about 10 to 15 minutes. Things eventually work their way back to about 30 minutes per batch / cycle. During the flush cycles I can see bits of biomatt being dislodged; washed out by the flow and gathered up by the CFC. Also, the CFC is running about twice as much felt as the previous system; about an inch an hour. This will cut my roll life down to about 70 to 75 days. This is about half the roll life I was getting prior to switching out the Version 2 for the V3 sump. One other noteworthy mentionable is that I was seeing a lot of foam generated by the bubble diffusers. The overflow / air escape was located toward the return pump section so there was no leakage but there was a layer of foam there and the overflow hole would burp out more every few seconds. This decreased when I reduced the carbon dosing. I supposed if I wanted, I could cut a new hole on the opposite side and collect / export the foam like a built-in skimmer.