2025 06-June 27 USP - Maxson headworks odor control project update

Date: 2025 06-June 27

Program update:

50% hydrogen peroxide
There is more sulfide than last year
the current pump capacity is maxed out
removing 1400 pounds of sulfide
adding 3600 pounds of hydrogen peroxide
2.6:1 removal ratio - lower than expected
Sammy Kohl says equipment can hypothetically dose up to 4300 gallons of hydrogen peroxide per day; we are currently maxed out at ~730 gallons per day
180 GPH/30 GPH * 730 gallons= 4300 gallons. The estimate is 1200 gallons per day could deal with the problem, based on the current efficiencies.
Iron (Ferrous Chloride) could be useful to mitigate issue at headworks
Dan: What is the source of iron? is there a data sheet? Just pickle liquor?
Chris Luss: We do not have information on percentage of ferrous chloride - information will be found.
Sammy: Do we want to go down that road of installing a ferrous tank?
Luss: Yes, probably, if Don approves. Might as well have it set up to go either way.
Sammy: Access to free iron, then some balance of using both will be more cost effective. Will get with project manager to get a tank off of his hands and bring it to Maxson. Where will we put it specifically? How will we get bulk deliveries? At the headworks junction box would pose a challenge for getting a truck back there.
Chris: Simplest would be at the junction box - we would need to discuss what was needed. Closer to the bar screens is possible, but we would need to create a truck pathway or piping.
Sammy and Dan Kile: Loading product from a truck takes 30 minutes to an hour.
Chris: It would be better if they could come in without opening the gate.
Mike: Staying on the road might be problematic due to all the regular heavy truck traffic (from moving the old ABF filter media).
Sammy: Would the area in front (east) of the BioAir 2 system be available for the ferrous chloride tank?
Sammy: A starting point - the same pump size for Ferrous Chloride as the hydrogen peroxide. 3 gallons per minute, 4300 gallons per day. We do not have the capacity to use gravity or atmospheric pressure - control is necessary.
Sammy: Is there potable water here?
Mike: Yes, at the bioair system, there is potable water for the trickle system.
Sammy: target install the week of the 17th of July. We are currently getting 50% removal. should we continue for now or should we stop until we get the ferrous chloride tank? We can swap the skid next week or wait until mid July as well.
Dan Kile: Do you want to save budget? What will it take to get it under control with just peroxide? Do you want to find out? There could be benefit in seeing what it takes. Being hot exacerbates the problem.
Chris Luss: Continuing to dose at the current, vs upping the dose.
Henry: ferrous is acidic, that is the limiting factor.
Sammy: the consumption of alkalinity
Mike: you're talking about 2.5 million dollars a year of peroxide. $5.80 per gallon of hydrogen peroxide.
Clayton: it would be a $60,000 dollar experiment, if we were to increase to 1200 gallons per day of hydrogen peroxide for three weeks.
Chris: let's talk to Don first.
Mike: changing the skid and upping the capacity of the pumping system would enable us to try more hydrogen peroxide if we wanted, but currently we cannot increase the dosing.
Chris: some dosing is better than none. But maybe we can choosing to full stop until we can get the ferrous chloride. We will talk to Don Hudgins on Monday.
Clayton: how will we couple the chemical delivery over the fence to the tank?
Sammy: truck to tank: Remote fill line, soft hoses, cam locked coupling - you really do not want to be offloading above eye level. The truck has a pump on it.
Henry Nakayama : how can we prevent spills.
Mike: Having the truck outside the fence would require a safety shower outside of the fence.
Sammy: Adding gravel for turn around purposes would be good.
Sammy: when will we meet next? Wednesday the 2nd?
Chris Luss: Wednesday is good, any time.
Mike: Anytime after 9