The Use of Perchloric-Nitric Acid Digestion in the Determination of Phosphoric Acid in Fertilizers

1953 ◽  
Vol 36 (3) ◽  
pp. 874-879
Author(s):  
L J Hardin
1988 ◽  
Vol 23 (2) ◽  
pp. 279-291 ◽  
Author(s):  
PR. Senthilnathan ◽  
J. J. Ganczarczyk

Abstract The exact estimation of biomass in the presence of carbonaceous carriers is an unresolved problem. Inaccuracy arises from the use of mixed liquor volatile suspended solids (MLVSS) determination as the measure of biomass, due to the volatilization properties of some carrier particles at 550°C. Problems are also associated with the differential ignition technique and nitric acid digestion technique, which are used instead of the MLVSS determination. Therefore, a method of calculating the biomass content by the determination of nitrogen in the mixed liquor suspended solids is proposed. In this paper, the proposed method is compared with the differential ignition technique. The Nitric acid digestion technique was not used in this study due to the explosive nature of one of the carbonaceous carriers when digested with nitric acid. It was found that calculation based on the nitrogen analysis gave a more reliable estimate of biomass in systems containing carbonaceous particles than the differential ignition technique.


2019 ◽  
Vol 11 (46) ◽  
pp. 5857-5863 ◽  
Author(s):  
Marianela Savio ◽  
Lucimar L. Fialho ◽  
Joaquim A. Nóbrega

The combination of dilute nitric acid digestion followed by recovery of the acid digests, represents steps towards green chemistry approaches: “reduce the use, recycle and reuse”, strictly following the major green chemistry recommendations.


2012 ◽  
Vol 40 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Abu Tweb Abu Ahmed ◽  
Suman Mandal ◽  
Didarul Alam Chowdhury ◽  
Abu Rayhan M Tareq ◽  
M Mizanur Rahman

The present study was carried out to determine the level of bioaccumulation of some heavy metals in a freshwater fish Ayre (Sperata aor Hamilton, 1822) collected from Rajfulbaria (23°48?56.36? N and 90°14?54.04? E) of  Dhaleshwari river. Four heavy metals, namely chromium (Cr), copper (Cu), lead (Pb), and cadmium (Cd) were selected for this study. Metal concentrations were   determined by Flame Atomic Absorption Spectrophotometer after nitric acid  digestion of samples. The concentrations of accumulated heavy metals in fish were  also compared with the concentrations of metals in the sediments and waters of  that river. The level of bioaccumulations in different organs of S. aor were determined separately and compared among them. Average bioaccumulation levels  in S. aor were Cr: 1.458 mg/kg, Cu: 31.500 mg/kg, Pb: 18.776 mg/kg and Cd:  0.487 mg/kg of dry weight. The levels of heavy metals in sediments were Cr: 27.393 mg/kg, Cu: 37.450 mg/kg, Pb: 15.797 mg/kg and Cd: 2.083 mg/kg, and in water were Cr: 0.130 ppm, Cu: 0.000 ppm, Pb: 0.201 ppm and Cd: 0.001 ppm.The bioaccumulation of these four heavy metals in fish organs, sediment and  water samples were also compared with FAO approved standard levels and other  related studies, and found that the levels of bioaccumulation in the Dhaleshwari river exceeded all the standard levels. DOI: http://dx.doi.org/10.3329/bjz.v40i1.12904 Bangladesh J. Zool. 40(1):147-153, 2012


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