BET Continuous pH monitoring

[gilles56]

Hi,

I am looking at the Biological Effluent Treatment plant (following ammonia stipping) where Nitrification and Denitrification are taking place in a single basin.

pH needs to be continuously monitored in order to preserve sludge activity.

Could you please advice me on a pH meter and probe the most appropriated. The plan is to be able to alarm operator via Artifial Neural Network if the pH goes out of range (pH range 6-10).

Also, what would be a safe process to add alkalinity straight to the basin while minimising overdosing risks?

Many thanks in advance

 

[saxon]

gilles56, Check with either Honeywell or Foxboro for pH probes, Controllers, Recorders and alarms. While you're at it, pickup the ISA text on pH Control. It can be ordered from the ISA at:

http://www.isa.org

It contains everything you ever wanted to know and then some.

Hope this helps.
saxon

 

[alexkoo]

Our Water Supplies Department has some experience on analyzers for pH, turbidity, chlorine and fluoride. These instruments are subjected to fouling, bubbles and pH value fluctuations(for chlorine and fluoride)

Most pH probes with KI solution work pretty well due to direct reaction with the Hydrogen ions,easier to get good results when compared to other type of analyzers. But the important thing would be their reliabilty wrt meantime between maintenance/cleaning service to get them to an accuracy figure(say within 0.2 pH value on field, though 1% claimed by mfy in lab)

I think the most important issue would be finding a pH probe with separate auto-cleaning device, ultrasonic is out of question due to ineffectiveness(Great Lakes), E&H would be slightly better with HCL injection mixed with water(in your case, muddy water??) Zellweger seems to perform best since the injector is air compressor driven and a power source is easier to find when compared to clean plant water.