Phosphate Reserve

Hardness breakthrough problems generally manifest as a periodic but sudden drop in alkalinity and a loss of phosphate reserve in the boiler. Reasons for hardness breakthrough include ... 

NOTE In lower pressure FT and WT boilers, internal treatment programs using phosphate are common and a small phosphate reserve is permanently maintained. 

Where high residual calcium leakage occurs in the FW, the phosphate reserve is lost and the boiler water alkalinity is reduced. This is not the same problem as hideout, which is the apparent loss ofBWphosphate and other salts in higher pressure WT power boilers operating under high load conditions. 

Higher than desirable phosphate reserves when using a coordinated phosphate program (20-50 ppm phosphate rather than 5-10 ppm)... 

NOTE Sufficient caustic is still required to maintain a suitable OH alkalinity reserve. Tests to confirm the presence of adequate alkalinity and a permanent phosphate reserve should be conducted frequently, normally at least once per day. 

The phosphate requirement is primarily based on the FW hardness, so the lower the hardness, the lower the phosphate demand. Where hardness levels are continuously low, the phosphate reserve should be maintained closer to the minimum of the specified range (typically 30-60 ppm P04 for FT boilers operating up to 30 bar, 435 psig). Conversely, the phosphate reserve should be higher with variable or higher FW hardness levels. If higher phosphate reserves are required, the hydroxide alkalinity should be increased accordingly. 

For precipitating phosphate programs it is necessary to ensure adequate BW alkalinity in addition to the phosphate reserve. Sodium hydroxide should be used. The alkalinity feed-rate is based on FW consumption and calculated as follows ... 

FWCaH = FW calcium hardness, in mg/1 (ppm) CaC03 RBWP04 = Required BW phosphate reserve in mg/1 P04 COC = Cycles of FW concentration present or desired in the BW... 

If maintaining phosphate reserves toward the upper end of the range, ensure caustic alkalinity is also high. Try to ensure an OH P04 ratio of 10 or 12 to 1. 

Where relatively expensive products such as terpolymers are employed in conventional programs, feed rates are not as high as, say, PAA, because of improved terpolymer performance. As an example, where a product such as Acumer 3100 is employed in phosphate-cycle programs, typical BW polymer requirement is 10 to 15 X COC active product, with a phosphate reserve of 30 to 60 ppm and perhaps 10 to 15 X COC. 

Control program on phosphate reserve (30-60 ppm P04), but also sulfite reserve (30-50 ppm S03) and P alkalinity (400-800 ppm as CaC03). 

Consequently, it is possible to select an operating pH level high enough to ensure magnetite film stability, yet low enough to prevent the formation of free caustic, together with a Na P04 ratio that provides the selected pH range and an adequate phosphate reserve. 

This program was originally devised for non-highly rated boilers. It requires that the bulk BW Na P04 ratio be permanently controlled below 3 1 and typically at a ratio of 2.85 1. The original recommendations for phosphate reserves have tended to move around a little in recent years. 

For any specific boiler application, the general area of phosphate equilibrium concentration may produce phosphate reserves of below 1.0 ppm P04 and an operating pH level of around 9.0... 

Maintenance of a phosphate reserve is not essential provided that a minimum carbonate alkalinity of 250 mg/kg can be maintained, depending on the alkalinity of the FW and the working pressure of the boiler, or that an appropriate program of transporting polymers is employed. 

During the recovery period from exercise, ATP (newly produced by way of oxidative phosphorylation) is needed to replace the creatine phosphate reserves — a process that may be completed within a few minutes. Next, the lactic acid produced during glycolysis must be metabolized. In the muscle, lactic acid is converted into pyruvic acid, some of which is then used as a substrate in the oxidative phosphorylation pathway to produce ATP. The remainder of the pyruvic acid is converted into glucose in the liver that is then stored in the form of glycogen in the liver and skeletal muscles. These later metabolic processes require several hours for completion. 

These three equations represent the wet process method in varying degrees of simplicity and depend on the phosphate source used. There is usually a high percentage of fluorine in the phosphate, in which case the mineral is called fluorapatite. It is mined in Florida, Texas, North Carolina, Idaho, and Montana. The United States has 30% of known phosphate reserves. 

This program formulation will tend to be dosed continuously to achieve a total phosphate reserve in the recirculating cooling water based on calcium hardness (as ppm CaCC>3), as shown here. 

Nevertheless, the phosphate reserves are low, also a low M alkalinity. Is the correct amount of Chemical 1 being added Or is there some calcium phosphate/carbonate deposition occurring (high turbidity) Is correct amount of stabilizer Chemical 2 being added Distributor to determine facts ... 

If significant phosphate is present, it is possible that a stabilized phosphate program has been used and the O-P ratios have not been maintained correctly, or the total phosphate reserve has been too high (check the makeup for phosphate content), or the reserve phosphate specific dispersant has been maintained at too low a level in relation to the calcium hardness. 

In eukaryotes, the function of PolyP as a phosphate reserve is probably related to the action of different forms of exopolyphosphatases and endopolyphosphatase. 

Thus, in spite of the fact that animal cells, probably with the exception of bone tissue cells, do not need PolyPs as phosphate reserves, the functions of these biopolymers are still... 

In the S. cerevisiae synchronous culture, an increased P uptake from the culture medium during DNA synthesis was observed (Gillies et al., 1981). At a high level of external Pi, this uptake provided the necessary phosphorus level in cells and the 31P NMR-visible PolyP remained constant. However, if the external Pi content was low, this PolyP was consumed, acting as a substitute for the phosphate reserve (Gillies et al., 1981). 

Phosphate reserve Phosphate reserve Cationes chelation... 

PHA (polyhydroxyalkanoate) 23, 46, 47, 48, 55 phosphate limitation 132 phosphate overplus 54, 56, 94 phosphate reserve 91 phosphate starvation 153... 

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