Ammonia Removal -- Control Parameters for Biodegradation 2

[WildRiverRat]

Installation of NOx reduction technologies at coal-fired power plants can potentially result in ammonia nitrogen concentrations of 0 to 600 mg/kg on the coal fly ash. When rain falls on this ammonium bisulfate laden ash, it is expected to leach. I am trying to identify control parameters for achieving biological treatment of ammonia in ponds which receive this ammonia-bearing stormwater run-off. Preliminary estimates of ammonia concentrations in the stormwater runoff are in the 3 to 28 mg/L range and some of them in the 30 to 100 mg/L range. I need temperature ranges, residence time ranges, pH ranges, and other potential control parameter ranges. I would appreciate it if someone could point me towards EPA studies or other classic reference works on treating ammonia in wastewater. Wastewater treatment at most of these facilities has traditionally relied on pH adjustment and the immense assimilative capacity of huge -- 15 to 30 acre -- ash ponds. I am trying to determine how to augment the smaller ponds to improve their assimilative capacity for ammonia, and when to warn management that a a package plant or trickle filter or some other type of treatment may be necessary.

 

[Muggle]

Trickle filters will transform ammonia (NH3/NH4) to nitrite and nitrate (NO2/NO3) whih may not resolve your problem. Typically, the fluctuating ph, the alkalinity, the wastewater temperature, and DO have to be maintained 24/7 in order for biological consumption/reduction of ammonia/nitrogen compounds. Heavy metals, salts and other toxins will effect the biological filtration.

For small pond eradication of nitrogen compounds and heavy metals, electrolytic treatment would be advised, especially as your levels jump from 28mg/l to 100mg/l at any one time. Electrolytic can be accomplished in-situ and will not be effected by ph, temperature, alkalinity, etc. Such systems are used to reduce/oxidize nitrogen, sulfur and carbonates in manure wastewater lagoons, and they are at a far higher levels then you ahve here. Lagoon size will determine rotational rate, which must account for holding time prior to release/dump.

Dave Orlebeke/Aquatic Technologies
PS If have further questions, let me know.

 

[WildRiverRat]

Is the end product of electrolytic treatment nitrogen?
Are any of these systems in-use in the southeastern US? What would be the ballpark range on capital costs and operating costs for electrolytic treatment for a 25 Million gallon pond? Flow from these ponds is rainfall dependent. Flow from one of the ponds under consideration is zero about 80% of the time.

 

[Muggle]

End product is nitrogen gas - released to the air, mainly as NO. No system used in southeastern US, unit going in in Colorado on tilapia production system in February, another going for tests in Canada. One spec'd for wyoming, but they are "budgeting" it in for 2004 for municipal wastewater lagoon of 3-acre (20' deep, so 20mil gallons approx).

Capitol cost dependent on holding time - as holding time determines the rotational rate to meet whatever reduction limits you need. 20-million gallon system with a nitrogen count of 100ppm, rotating at 1200gpm through the electrode cells, would run about $30-35,000. If you needed a pump to rotate, figure another $25,000. Operational cost for the electrolytic system would be 40amps/230v/1phase 24/7 or 9.2kW per hour. Pump would probably be 20hp at 230/460v/3-phase, drawing 30 amps, unless you already had existing pups operating that we could divert flow through. Space requirement would be approx. 9' long, by 4' wide by 5' tall. electrode distribution manifold could be placed outside (that is the majority of the space required) but the power controller would need to be inside.

Dave Orlebeke/Aquatic Technologies

 

[waterexpert]

WildRiverRat

Don't be misled-biological or chemical treatment is far more common for applications of this type. Treatment of ammonia in wastewater is a common feature of every wastewater system in the world. Relatively high strength ammonia wastewater such as you have may however be more suited to chemical removal than biological treatment.

I cannot comment on the applicability of electrolytic treatment to fish farms (the supposed area of expertise of "Muggle&quot,but can assure you that biological and chemical treatment of ammonia is commonplace, unlike electrolytic treatment on this scale.

Since "Muggle" makes ridiculous claims elsewhere on these pages (such as that the electrolytic system suggested electrolyses sulphate to elemental sulphur), I would suggest you ask a professional engineer's opinion of his proposal. As he says himself elsewhere in this site, he has no professional qualifications whatever.

For expert advice on wastewater treatment, try a reputable textbook such as "Metcalf and Eddy: Wastewater Engineering"
You will find no mention of electrolytic tretment of ammonia.

 

[Muggle]

First - municipal wastewater plants all over the Unied States are all under pressure to reduce nitrate - as all can not meet current EPA discharge regulations during the winter months, and most small municipalities can not meet them at all. If you don't understand electrolytic application - don't comment on it. It is currently under trials by USDA and others for n-nirtrogen removal for hog and dairy manure wastewater - where n-nitrogen runs in 1000-3,000ppm and volumes are 325,000-1,million gallon gallon holding pits with inloading 24/7. For those involved in electrolytic application - they find power requirements vastly less then RO or other treatments.

Biological filtration will work - but has limitations, just as all systems do. Merging technologies to overcome the limitations of each usaully works best, and does not require either the land space or increase capitol/operational costs.

Just because something is "commonly used" does not mean it is the best - for case in point - look at chlorination of drinking water and all the problems that has created.

Good luck WildRiverRat - but you might want to contact EPA and the US Naval New Technology Divisions - they probablycan give better info then you'll get here!

 

[waterexpert]

Wildriverrat-

Without getting any further into an argument here, the most usual treatment is a biological one for problems such as yours. The energy costs will be far less than for electrolysis. To say electrolysis is cheaper than RO is probably true. Whether it will work or not is however a question which is more difficult to answer. No-one would however suggest RO as a solution to your problem. The objections which are being raised to the biological treatment route are spurious. Removal of nitrite and nitrate can also be carried out by more advanced biological means. Again, this is the conventional approach. It works.

As a professional engineer I understand all approaches. It is not I who has the limited approach. Electrolysis is not appropriate here.

To a man who only has a hammer, everything looks like a nail. Similarly, if you look at Muggle's other posts on this site, he suggests the same few approaches to everyone, for everything. Electrolytic treatment is what he sells for a living. It is unlikely that the results of his installations are analysed rigorously.

Muggle's posts elsewhere on this site make it clear that he has very little understanding of the basics of electrolysis, his supposed area of expertise. It's not just me who thinks so. Have a look at the comments on his suggestions. Most people are too polite to come right out and say it, but read between the lines.

I have no wish to cause unnecessary offence, but professional qualifications are more than just pieces of paper,and it is my understanding that practicing as an Engineer in the US without a licence is a criminal offence.
I have degrees in Environmental Science, Biotechnology and Chemical Engineering, and am a Chartered Chemical Engineer, the UK equivalent of PE.Most of the other people who post replies to questions on this site are similarly qualified.
I am not going to enter into argument with unqualified salesmen. It is my understanding that promoting and selling are not allowed in the forums. Hopefully this it therefore a problem which will resolve itself.

 

[WildRiverRat]

Waterexpert and Muggle -- I appreciate all of your comments. There's no need to be argumentative. The state environmental regulatory body at one of the plants in question is even more conservative than my management, so the chances of deploying anything which is less than 30 years old which hasn't been tested at 3 or more other power plants are about zero. I've got the second edition of Metcalf and Eddy's Wastewater Engineering on my desk, but haven't had time to open it for the past month. The current pressure is on to computer model the expected biological decomposition of ammonia nitrogen in the ponds. If there is forum for user reviews on EPA software packages, I'd like to know about it.

 

[waterexpert]

There is a package commonly used here in the UK for the job you wish to do called Hydromantis....