No announcement yet.


  • Filter
  • Time
  • Show
Clear All
new posts
  • #31

    carp also produce urea. You are correct in that 85% plus is in the form of ammonia emitted form the gill, but urea is the rest. It goes through mineralization and/or 'flushing'.


    • #32

      As just a basic thought so it does not get sticky, most fish are Ammonotelic. Fish lack the urea cycle for removing Ammonia from the blood. They do release nitrogenous waste compounds for osmoregulatory purposes. There are exceptions as always.


      • #33

        absolutely. But just so no one looses the plot, Mike and I are both curious about the fact that TTs and bakkis do reduce nitrate and we are investigating the 'leak' theory. Ammonia leaves solution with evaporation. Fish produce some urea. That's all we know ---


        • #34

          KK: Excellent point. Urea is less volatile than ammonia. In the presence of water, however, urea breaks down into ammonia and carbon dioxide. The nitrogen content of many garden fertilizers is now urea-based. It is fairly stable if kept dry. When moistened, it becomes quite unstable. This is why a fertilizer applied to the soil surface can "burn" a plant when watered. The "burn" is the toxic effect of ammonia.

          Since fish emit ammonia rather than the more complex urea, it is more immediately volatile. The difference, of course, is the ammonia is also immediately diluted by the water body, while urea will be more concentrated in the mammalian wastes... until diluted in the waste water effluent.

          The Sharpe & Harper study measured ammonia (NH3), ammonium (NH4-N) and nitrous oxide (N2O)... and total nitrogen. So, the data is useful, I think, because they measured the volatile compounds which comprise a far greater percentage of the waste produced by fish.

          As I continue to review the article, I am left with lots of questions... most related to the continued volatilization of ammonia from the soil surface. And, I do not feel competent to interpret the raw data charts beyond what the authors express. I expect they published further articles drawn from their data. Maybe I can get around to locating them next week.

          I think what impresses me most is that they found 76% of total nitrogen was lost to the atmosphere after 24 hours. Studies of slurries and solid manures applied to soil show losses to the atmosphere, but not so dramatically. The overhead sprinkling of wastewater resulted in greater volatilization of the ammonia content than other studies show for the spreading of more solid waste forms.

          I do not understand most of what is involved. I'll need to track down some more studies focused on other aspects of the processes involved. In the meantime, I think it is sufficient for me to be convinced that volatilization of ammonia can be substantial when atmospheric contact is maximized. Just how substantial remains an open question, but it is consistent with the widespread observation that use of TTs, Showers and other highly aerobic filtration techniques coincide with dramatically reduced levels of nitrate and gives reason to believe the use of such techniques is the cause of the lowered nitrate levels.


          • #35

            I agree Mike. Ammonia volatilization is the only possible explanation for lowered nitrate concentrations in ponds with TTs. Although the percentage of ammonia available for volatilization is very small at the pH of fish ponds, it is important to remember that there is an equilibrium between ionized and unionized ammonia. As soon as that small percentage of ammonia is volatilized, it is immediately replaced as the equilibrium shifts.

            On large and heavily aerated fish and shrimp farms (and pig farms too) it is possible to measure the difference in atmospheric ammonia from the windward to the leeward side of the property. This is despite the fat that the pH of the pond water makes very little of the ammonia available for volatilization at any particular moment in time.

            From a regulatory standpoint this creates a conundrum for EPA. They regulate effluent water quality but air quality is largely ignored unless the odor is especially offensive. However, all that ammonia "leaking" away with the prevailing winds will eventually be "washed" from the air when it rains and deposited across land and sea.

            -ste vehop


            • #36

              Ammonia in the atmosphere is a source of pollution. Animal wastes are the largest single source of ammonia emissions. It can be a component of acid rain even though ammonia itself is a base. It helps produce ammonium sulphate and nitric acid which increases the acidity in the soil.


              • #37

                What would really be interesting is that we find a tt is actually an anoxic reactor with anaerobic bacteria doing most of the work? After reading about Anammox reactors, this method of ammonia oxidation and removal sounds possible?


                • #38

                  Kong that is part of the answer also, I suspect. I believe that the nitrogen waste products ( in all stages) die of a 'thousand cuts' in a TT environment. And one of the 'nicks' is possibly the 'yet to be named' photo bacteria found in TTs used in the waste treatment industry. This is a light loving photosynthetic bacteria that grown ON the biofilm polymatrix.
                  I also suspect that some nirtite is lost to the volitilization process and certainly the intermediate species of nitrogen still in gaseous form are lost to the greater atmosphere. JR


                  • #39

                    Morning Mike, I found this from text

                    Ammonia- chemical formula NH3
                    1 atom of nitrogen
                    3 atoms of hydrogen
                    Chemically combined to form 1 molecule of ammonia

                    Molecular weight, 17.01
                    Density 8.5
                    specific gravity, 0.59
                    Melting point - 75 c
                    boiling point - 38.5c

                    This is about the only known compound of nitrogen and hydrogen to exist in a free state. It exists in small quantities in the atmosphere and also in rain water. It is produced in considerable quantities in decomposition of animal and vegetable bodies which contain nitrogen.

                    Properties: It is a colorless gas. It has a pungent and characteristic odor which in the undiluted state acts as a powerful irritant, bringing tears to the eyes , and if accidentally if accidentally inhaled even in small quantities, destroys the mucus membrane of the mouth and nose and may even be fatal by it's action on the lungs.
                    Like other liquified gases, liquid ammonia is very volatile, producing great cold when it evaporates.
                    The gas is remarkably soluble in water having a great affinity for it. For example, At 15 c water will dissolve 727 times it's own volume.
                    The concentrated solution [of dissolved ammonia in water] readily evokes the gas when warmed and may be frequently used a sourse for the gas form.

                    Ammonia is a non supporter of combustion abd is non flammable at room temperature. But when gently heated it takes fire and burns with a greenish yellow flame.


                    • #40

                      Originally posted by kingkong View Post
                      Pig vs. Fish .....round 1 of Urea vs. Ammonia
                      Just so there is some understanding of the basic chemistry of waste, it might make the pain easier to handle.
                      Fish release nitrogen as free Ammonia (NH3) which is very toxic and would kill a land organism if not promptly removed. Fish are the only members of the animal kingdom to excrete nitrogen this way. Since they are surrounded by water, they can convert the amino group to Ammonia and then release it via the gills into their environment.
                      Pigs, along with all land animals, deal with nitrogen in a completely different way. To avoid the toxic Ammonia, they convert the amino group into Urea via the liver. Once synthesized, it is then released from the pig as urea or (NH2)2CO. This is a combination of carbon, nitrogen, oxygen and hydrogen.
                      Now we are trying to compare the volatility of Ammonia to Urea as it enters the atmosphere. Could there be any correlation drawn...I don't know.
                      An excellent point and would be a good explanation why in the spring there are such large numbers of dafnia appear in cow pasture ponds . As the nitrogen compounds release amino acids and minerals fertalizing the growthof algae which the plankton feeds on . I wonder if using UV lights causes more harm than good especially if we are trying to raise the fish to their true potential ? It is bad enough to deprive them of a natural mud bottem but the plankton loss mightbe too much ?



                      • #41

                        What would really be interesting is that we find a tt is actually an anoxic reactor with anaerobic bacteria doing most of the work?
                        I guess that possibility cannot be ruled out all together Gary. However, it would seem to be a less likely explanation than ammonia volatilization. As James said above somewhere, you would expect denitrification to operate more effectively in a submerged filter where there are more anoxic areas. Anoxic areas can exist anywhere - even in floating detritus particles only a millimeter or so in size. But for denitrification to do any good, the process has to proceed all the way to the end point of nitrogen gas. It is a sequential process where nitrate (NO3) is converted to nitrite (NO2), then nitric acid (NO), then nitrous oxide (N2O), then finally nitrogen gas (N2). Nitrogen gas is very inert (the atmosphere is full of it) and readily volatilized. However, if the anoxic zone is disturbed before the nitrogen gas end point is reached, the process reverses itself, aerobic nitrification takes over again, and the partially reduced nitrogen is converted back to nitrate. In a TT you would expect the anoxic zones to be small in size and transitory making it difficult to get all the way to the denitrification end point.

                        There is another type of denitrification where nitrate is converted directly to ammonia. This process takes a special microbe which is less common than the typical anaerobe looking for a source of oxygen to scavenge. I guess it is possible that something about the TT could favor this specialized anaerobe. But, then you are back to ammonia volatilization as being the primary avenue for off-gassing nitrogen.



                        • #42

                          I am bumping up this old thread, with lots of good technical information. A discussion on another board about a pond with no detectable nitrate over an extended period of time got me interested in re-visiting the subject of nitrate. So, over the past few days I've been doing a bit of reading. I came across something I do not recall being part of the discussion of nitrate in the koi pond: The Environmental Protection Agency's conclusions about nitrate in drinking water. Lots of studies with lots of controversy, but there is a scientific consensus that EPA standards are appropriate.

                          The Maximum Contaminant Level (MCL) set for nitrate is 10 ppm, and for nitrites it is 1 ppm. Lower levels may well be more appropriate, but given present technology and resources (i.e., cost), EPA has concluded that this is the lowest level to which water systems can reasonably be required to remove nitrate from drinking water. Much of the controversy is over so much nitrate being allowed, with there being those who would set it much lower despite cost factors.

                          The health effects of nitrate consumption by people are notable. Short-term: Excessive levels of nitrate in drinking water have caused serious illness and sometimes death, particularly in young children. The serious illness in infants known as Blue Baby Syndrome arises from conversion of nitrate to nitrite by the body, interfering with the oxygen-carrying capacity of the child's blood. This can be an acute condition in which health deteriorates rapidly over a period of days. Symptoms include shortness of breath and blueness of the skin. The same processes occur in everyone, but the young body cannot handle it. Needless to say, there is no disagreement that people of all ages would be better off if no nitrate was in drinking water. Long term exposure to nitrate or nitrite levels above the MCL has considerable impacts on a large percentage of those exposed: diuresis, increased starchy deposits and hemorrhaging of the spleen.

                          Impacts on fish are not so well and thoroughly studied. However, even skimming studies of the impacts on humans and mammals causes me to question the oft-repeated notion that nitrate is not a terribly bad thing for our koi. I have been pleased with myself about keeping nitrate levels below 5ppm as a general rule. Now, I wonder if even this is high in terms of a constant exposure for life.


                          • #43

                            As some on this BBS will know, the Koi Organisation International (KOI) has information in their KOI Guide on various aspects of water quality. For Nitrate the broad ranges on the Water Quallity chart are labeled as follows:

                            Reproduction: 0-5ppm
                            Growth: 4-40ppm
                            Survival: 40-80ppm
                            Slow Death: 80-250ppm
                            Rapid Death: 250+ppm

                            There are notes associated with the chart. The chart has also info on Nitrate, pH, Dissolved Oxygen, TAN, Hardness, and temperature. Anyone wanting more info about the KOI chart or wished to become a certified koi keeper should contact KOI: K.O.I. |
                            Koi keeping is not a belief system; it is applied science with a touch of artistry.


                            • #44

                              Originally posted by MCA View Post
                              As some on this BBS will know, the Koi Organisation International (KOI) has information in their KOI Guide on various aspects of water quality. For Nitrate the broad ranges on the Water Quallity chart are labeled as follows:

                              Reproduction: 0-5ppm
                              Growth: 4-40ppm
                              Survival: 40-80ppm
                              Slow Death: 80-250ppm
                              Rapid Death: 250+ppm

                              There are notes associated with the chart. The chart has also info on Nitrate, pH, Dissolved Oxygen, TAN, Hardness, and temperature. Anyone wanting more info about the KOI chart or wished to become a certified koi keeper should contact KOI: K.O.I. |
                              Thanks for sharing MCA. I'm glad to know I'm now out of the survival mode range of a few months ago and into the reproductive range. I just hope they don't start breeding like rabbits.


                              • #45

                                Originally posted by JasPR View Post
                                Don, that makes no sense to me? submerged filters would have far more potential for anaerobic proliferation than oxygen rich and clean TT media. If I pull out the plastic media from one of my towers it will be stained brown but clean as a whistle otherwise. The base is filled with clean water up about 26 inches in an eight foot tower. There is no point in rinsing it as it IS being rinsed 24 X 7 and no waste or organic is evident. On the other hand, we can rinse one of my submerged Jmats and you will get LOTS of organic mulm, the natural home of anaerobic bacteria species ( low oxygen leading to anaerobic proliferation , leading to decay, leading to lower oxygen, leading to more anaerobics). Anaerobic bacteria exist in two ways in a filter setting, 1) as a member of a nitrifying dominate community located at depth or dispursed as a clean up crew in all areas of the film. 2) in an environment that favors them exclusively- slow moving water, rich in organic sediment and resulting in less than saturated water conditions. I could see this type of mix easily set up in a BB, but I have trouble appreciating it occurs in a TT MORE than in a mulm rich BB? JR
                                MikeM, thanks for bringing up this old thread, which showed you'd taken a lot of time and effort to research on, along with useful inputs from others such as JR and Eugene. What JR mentions about submerged jmats having characteristics favoring the development of anaerobic conditions I also take as a license to interpret as favoring anoxic conditions. As my understanding goes, anaerobic conditions will favor reverse nitrification, whereas anoxic conditions favor denitrification. Reverse nitrification will produce nitrites and ammonia from nitrates, whereas denitrification converts nitrates into N² gas.

                                A jmat can be anaerobic or anoxic, whereas a filter bottom can only be anaerobic when filled with mulm and sediments. The reason being that a jmat, having a large surface area, is still in closer proximity to oxygen-laden water than a filter bottom. A dirty filter bottom will reek and smell foul when a thick layer develops, because of the putrefication (anaerobic decomposition) occurring. Whereas in a jmat, it is less likely to occur because of gravity. When the mulm becomes too thick, it falls off to the bottom, lessening the likelihood of developing anaerobic conditions. Not that it won't happen, but when you clean the jmats in situ, from time to time, you likely end up free the jmat from developing extreme conditions that lead to anaerobic decomposition. But it is a very likely that you never end up ridding the jmat of all the mulm, and that would not be a bad thing.

                                It's not a bad thing because for one, to rid all of the mulm would entail also flushing out too much of the biofilm of nitrifiers that have already colonized there. And also, the pockets of mulm embedded create possible anoxic zones, where heterotrophic bacteria could possibly operate and do the job of denitrification. I only say possibly, as you would have to consciously, if not accidentally, be cultivating conditions that favor the dominance of heterotropic bacteria that denitrify.

                                Which leads me to believe that, until my recent thorough flushing of my jmats, my biofilters had become anoxic, and was causing my nitrate levels to go down to 10 ppm, without ammonia and nitrites going up. And the reason for it becoming anoxic, is that I have kept those anoxic/anaerobic regions from working against me by the addition of beneficial microorganisms em1 constantly over a period of two years. It must have taken this long for that colony of biofilm to develop to enough numbers to have this effect. The danger, though, is that this salutary condition can easily be overturned and become toxic. When I allow anaerobic bacteria to dominate, it will. Which means, regular cleaning of jap mats and filter bottoms, as well as regular additions of em1.


                                All content and images copyright of: