If you must remove phosphorus from your wastewater, it is likely you must also remove ammonia- nitrogen. Nitrification, the process of oxidizing ammonia to nitrate and nitrite, is optimal in the narrow range of pH from 7.5 to 8.6. A pH below 7.2 results in a compromise of nitrification efficiency. In addition, nitrification consumes a large amount of alkalinity: 8.64 mg of HCO3– per mg of ammonia-nitrogen oxidized. In most domestic wastewaters, the amount of alkalinity is adequate to support the oxidation of the ammonia UNLESS you also remove phosphorus. If you remove phosphorus, your choice of coagulant for phosphorus removal can decimate your alkalinity, driving your pH below the optimal range and requiring additional alkalinity to maintain the pH and support the nitrification reactions.
Traditional coagulants are inefficient AND strongly acidic
Traditional ferric or aluminum-based coagulants can hit your nitrification process with a one-two punch. First, these coagulants have very low pH, often < 2. Second, they have only a moderate attraction for phosphorus, which means that a large quantity of these coagulants is required to achieve a low total phosphorus limit, usually 3 to 7 or more molecules of coagulant per molecule of P removed. This ratio goes up as the P limit goes down. The net result is massive quantities of alkalinity are consumed, requiring corresponding quantities of additional caustic. This presents both operational and safety challenges.
Neo WaterFX preserves alkalinity
However, there is an alternative. Neo WaterFX has a strong attraction to phosphorus, tightly bonding with the phosphorus to remove it in a dense precipitate. Because the preference for phosphorus is so strong, much less Neo WaterFX is needed to remove the phosphorus, typically just one molecule of coagulant per molecule of P. In addition, WaterFX is much less acidic. The net result is that WaterFX adds 1,000 to 2,000 times LESS acidity, consuming far less alkalinity than either ferric or aluminum-based coagulants. Less alkalinity consumption leaves more for your nitrifiers, and dramatically reduces or even eliminates the need to add caustic to preserve alkalinity and maintain your pH.
Get an evaluation
Wouldn’t it be wonderful to drastically reduce or even eliminate your caustic feed? Find out how WaterFX can help preserve your alkalinity, keep your nitrifiers happy, and meet even the lowest phosphorus limit. Contact us for a free consultation. https://neowatertreatment.com/contact/
