Alkalinity and buffers

These builders are generally available as sodium, potassium, or mixed-metal salts, the latter being more soluble in water but also more costly. The widespread use of sodium TPP (STPP) in LADD formulations can be attributed to the many functions it performs during the wash cycle. Besides its efficient sequestration of hardness ions, STPP works to disperse and suspend soils, enhance the surface action of anionic surfactants, solubilize proteinaceous soils, and provide alkalinity and buffering action. Pyrophospates have been included in some LADD formulations because of its better solubility properties relative to tripolyphosphate [20],... 

Alkalinity and buffer capacity Dissociation of ammonium ions to ammonia results in the production of hydrogen ions. Unless the water column or soils are well buffered, the medium can be acidified and the rate of ammonia volatilization can decrease. Thus, a water column with high alkalinity and calcium carbonate content can buffer the system and maintain high-pH conditions. Alkalinity is affected by the balance between photosynthesis and respiration by algae and submersed macrophytes in the water column. Ammonia volatilization losses are directly proportional to the alkalinity of the system. 

Alkaline and buffering agents ammonium hydroxide, triethanolamine, ethanolamine, ammonium carbonate... 

Further tests demonstrated that inhibition performance was maintained in fully formulated muds. A further advantage of the use of KCl and optionally glucose syrup with borate is that the relatively low water solubility of borate is enhanced by the presence of both of these additives. In addition, borate-based muds are naturally mildly alkaline and buffer well against changes in pH. 

Fig. 2. Schematic diagram showing (1) a typical baseline porosity curve, (2) the chain of mineral reactions that are capable of most significantly chemically enhancing porosity, and (3) the parallel and serial organic and inorganic reactions that control alkalinity and buffer the fluid pH...

The discussion above is for a rock-fluid system containing carbonate minerals in the absence of carbonate minerals, the alkalinity and buffering... 

The validity of the results of this modeling techniques is based on correctly assessing the mechanisms controlling the alkalinity and buffering character-... 

Sa.tura.tion Index. Materials of constmction used in pools are subject to the corrosive effects of water, eg, iron and copper equipment can corrode whereas concrete and plaster can undergo dissolution, ie, etching. The corrosion rate of metallic surfaces has been shown to be a function of the concentrations of Cl ,, dissolved O2, alkalinity, and Ca hardness as well as buffer intensity, time, and the calcium carbonate saturation index (35). 

In the eastern United States, acid rain consists of 65% sulfuric acid, 30% nitric acid, and 5% other acids. In the West, windblown alkaline dusts buffer the acidity in rains occurring over many rural areas, whereas in urban areas 80% of the acidity is due to nitric acid (28). Average pH in rainfall over the eastern United States for the period April 1979-March 1980 was less than 5.0, with some areas less than pH 4.2 (29). The lowest annual pH recorded was 3.78 at De Bilt, The Netherlands, in 1967, and the lowest in an individual rainfall was 2.4 at Pitlochry, Scotland, on April li) 1974 (30). 

The iron-sponge material is normally specified to have a size distribution with 0% retained on 16 mesh, 80% between 30 and 60 mesh, and 100% retained on 325 mesh. It is purchased with a moisture content of 20% by weight and buffering to meet a flood pH of 10. Because it is necessary to maintain a moist alkaline condition, provisions should be included in the design to add water and caustic. 

The reasons why some anions exhibit strong inhibitive properties while others exhibit strong aggressive properties are not entirely clear. The principal distinction seems to be that inhibitive anions are generally anions of weak acids whereas aggressive anions are anions of strong acids. Due to hydrolysis, solutions of inhibitive anions have rather alkaline pH values and buffer capacities to resist pH displacement to more acid values. As discussed... 

Benzoate can be used as an anodic inhibitor and is effective at preventing waterline attack. Phosphate is also sometimes included. Sodium borate (borax) is usually added to the formulation to provide an alkalinity reserve buffer. Typically, a copper inhibitor such as benzo-triazole (BTA) or tolyltriazole (TTA) also forms part of a formulation and is used to provide yellow metal (copper and brasses) protection. 

Thus, spray-dried xylan/ESlOO microparticles were produced at different polymer weight ratios dissolved in alkaline and neutral solutions, separately. More precisely, xylan and ESIOO were dissolved in 1 1 and 1 3 weight ratios in 0.6 N NaOH and phosphate buffer (pH 7.4). Then, the suspensions were spray-diied at the feed rate of 1.2 mL/min (inlet temperature of 120°C) using a Biichi Model 191 laboratory spray-dryer with a 0.7 mm nozzle, separately. Cross-linked xylan microcapsules were also coated by ESIOO after spraydrying at the same conditions. 

Gill et al.21 Archival FFPE spinal cord tissue both paraformaldehyde-fixed frozen rat spinal cord tissue and paraffin-embedded same tissue To establish an optimal protocol for detection of low-abundance protein (NeuN) in human spinal cord FFPE tissue sections, testing three AR solutions of pH 6, alkaline, and acidic buffer, with three heating conditions 95,100, and 105°C Heating FFPE tissue sections in an alkaline buffer yields most effective AR-IHC staining results. 

In soils the organic matter (range 2 in Fig. 9.12) is a significant pH and pe buffer because it represents a reservoir of bound H+ and e When organic matter is mineralized alkalinity and [NO3], [SO ] increase and Fe(II) and Mn(II) become mobilized. Phosphate, incipiently bound to Fe(III)(hydr)oxides, is released as a consequence of the partial reductive dissolution of the Fe(III) solid phases. At lower pe values (range 3 in Fig. 9.12) the concentration of Fe(II) and Mn(II) further... 

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