Concentrations of organic acids

Select a bag filter that must operate at temperatures above 300° F and handle concentrations of organic acids in the wastewater. 

Organic acid fluorescence. In a similar manner to trace constituents, such as Mg, Sr and P, concentrations of organic acids present in speleothem calcite are sufficient to observe variation at temporal scales of less than annual in some cases (e.g.. Baker et al. 1993, Shopov et al. 1994). Organic acids (humic and fulvic) are formed in the soil by humification, and transported to the cave void by percolating waters where they are entrapped in precipitating carbonates. Under certain circumstances, where precipitation patterns are strongly seasonal and the nature of vadose percolation is such that seasonal mixing is incomplete, bands with different luminescent intensities can be differentiated after excitation with UV radiation. In other cases, bands are not observable but secular... 

Generate a standard curve for each acid by plotting area versus concentration of organic acid for each solution. To determine the concentration of organic acid present in the sample, calculate y for the line y-mx + b, where vis the peak area (A) measured in abundance units (AU) produced by the organic acid in the stock solution, m is the slope of the standard curve, x is the concentration of organic acid in the solution, and b is the y intercept. 

Table G2.2.3 Concentrations of Organic Acids Commonly Found in Various Fruit Juices"... 

Sour-tasting compounds are all acidic. The acidity of mineral acids is determined by their hydrogen ion concentration that of organic acids, however, cannot be defined in such simple terms. Thus, a solution of acetic acid tastes more sour than one of a mineral acid at the same pH (5) however, the mineral acid tastes more sour than the organic acid in equimolar solutions. The threshold concentrations of organic acids are pH dependent, yet the relationship is usually quite complicated. The threshold concentrations of formic, malic, and succinic acid increase with increasing pH, whereas those of acetic, butyric, and lactic acid exhibit the opposite trend (7). 

Table 1 Typical Threshold Concentrations of Organic Acids in Various Media...

FIGURE 8.2 Interfacial tension of 30% TBP-n-dodecane in respect to 0.6 M NaOH as a function of RCOOH concentration of organic acid. (Drawn from Nowak, Z., Nowak, M., Nukleonika, 26(1) 19-26, 1981.)... 

The optimization of the two-stage process has to be conducted taking into account the following specific factors (a) those parameters that may directly affect the catalytic cycle the type and concentration of organic acids, Mn2+, H202, as well... 

Table V. Equilibrium and Potential Gas-Phase Concentrations of Organic Acids Calculated From Wisconsin and Virginia Precipitation Measurements...

Some researchers have suggested that the estimated concentrations of organic acids in the soil solution are too low to promote significant... 

Williams et al. also measured DOC (Dissolved Organic Carbon) at average values of 138 and 238 pM for the dry and wet seasons, respectively. The annual volume weighted mean of 159 pM implies an annual deposition of about 0.4 moles C m. The acidity was basically determined by the concentrations of organic acids. The concentration of acetate was 9 3 peq and formate was 2.9 peq hk The average conductivity was... 

The effect of temperature is linked to the availability of water. The dry air of hot, arid environments is an ineffective weathering agent. Vegetation and hence soil organic matter are sparse, and this reduces the concentration of organic acids. Moreover, close contact between rock particles and acid is prevented by the lack of water. Short-lived rainfall events may move surface salts into the soil, but the... 

It was initially speculated that the antifungal action of organic acids is based on intracellular acidification, because this inhibits glycolysis (Leyva and Peinado, 2005). However, results obtained with exponentially growing cells, both in batch (Warth, 1991) as well as chemostat cultures (Verduyn et al., 1990), showed that glycolysis was enhanced when cells were cultured in the presence of sublethal concentrations of organic acids. It was also detected that phosphofructokinase activity was not inhibited (Warth, 1991). 

Abbott, D. A. and Ingledew, W.M. 2004. Buffering capacity of whole corn mash alters concentrations of organic acids required to inhibit growth of Saccharomyces cerevisiae and ethanol production. Biotechnology Letters 26 1313-1316. 

Low concentrations of organic acids are not effective against Salmonella enterica sv. Typhimurium attached to broiler carcasses (Lillard et al., 1987 Tamblyn and Conner, 1994), and application could result in induction of tolerance, which in turn would have an impact on the virulence of a pathogenic invasive organism (Hill, O Driscoll, and Booth, 1995). 

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