Analysis of Hydrofluoric-Nitric Acid Stainless Steel Pickling Bath

McKee, W.E.; Hamilton, W. F.

doi:10.1021/i560141a013

Cited by 6 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Citric acid concentration was measured in terms of chemical oxygen demand (COD). Dissolved iron, chromium and nickel were present as Fe(III), Cr(III) and Ni(II), respectively . For this reason, these metals were added as ferric iron nitrate nonahydrate (98%), chromic nitrate nonahydrate, and nickel nitrate nonahydrate (98.5%) in batch incubations.…”

Section: Methodsmentioning

confidence: 99%

Denitrification of metallurgic wastewater: mechanisms of inhibition by Fe, Cr and Ni

Ramírez

Rangel-Mendez

Lopes

et al. 2017

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND Metallurgic wastewaters are acidic effluents containing large amounts of nitrate and heavy metals. Citric acid is one of the acids used by this industry and forms stable complexes with metal ions. The aim of this study was to elucidate the chemical aspects driving inhibitory or stimulatory effects of heavy metals on denitrifying processes, based on speciation analysis and monitoring key denitrification intermediates (nitrite and N2O). RESULTS Denitrifying sludge incubations were conducted with iron, chromium and nickel, in single and multi‐metal assays, using citrate and ethanol as electron donors. Ferric‐citrate complex, [Fe‐cit](aq), was readily consumed, while complexes of divalent metals, [Fe‐cit]‐ and [Ni‐cit2]4‐, remained very stable affecting denitrification. Nitrate reduction was affected by Ni2+, while nitrite and N2O accumulation was observed with NiCO3 and Ni(OH)2 oversaturation. [Cr‐cit2]4‐ resulted in overall denitrification inhibition, while species of [Cr‐cit]2‐ caused denitrification stimulation. CONCLUSION Fe and Cr inhibited the overall denitrification process, while Ni caused accumulation of intermediates. Synergistic inhibition imposed by multi‐metal systems revealed lower inhibitory effects compared with those observed by the sum of individual effects of metals. This study elucidates chemical aspects determining the effects of heavy metals on denitrification, which is relevant to develop efficient biological processes for metallurgic effluents. © 2017 Society of Chemical Industry

show abstract

Section: Methodsmentioning

confidence: 99%

Denitrification of metallurgic wastewater: mechanisms of inhibition by Fe, Cr and Ni

Ramírez

Rangel-Mendez

Lopes

et al. 2017

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

show abstract

“…1,500 97.0(97.2) 0.08 1 Mean of 4 determinations. 1 The value in parentheses is that obtained in the absence of I. 0 Hydrolysis time 20 min.…”

Section: Methodsmentioning

confidence: 99%

Spectrophotometric determination of aliphatic amines by acylation with cinnamic anhydride

Hong¹,

Connors²

1968

Anal. Chem.

View full text Add to dashboard Cite

A simple, sensitive method for the determination of primary and secondary aliphatic amines is based upon their conversion to N-substituted cinnamides by reaction with trans-cinnamic anhydride. After acylation of the amine in acetonitrile solution, the excess anhydride is hydrolyzed, the cinnamide is extracted into chloroform, and the amide is measured spectrophotometrically. The method is applicable to amine samples in the 1-5 pmole range; the standard deviation is 0.5-1.0%. Water and methanol do not interfere. The kinetics of the acylation and hydrolysis reactions have been studied, and a correlation can be demonstrated between acylation rate and basicity for many primary amines; sterically hindered amines react more slowly than would be anticipated from their basicity.

show abstract

Analytical Chemistry of Fluorine and Fluorine-containing Compounds

Elving

1954

Fluorine Chemistry

View full text Add to dashboard Cite

Analysis of Hydrofluoric-Nitric Acid Stainless Steel Pickling Bath

Cited by 6 publications

References 4 publications

Denitrification of metallurgic wastewater: mechanisms of inhibition by Fe, Cr and Ni

Denitrification of metallurgic wastewater: mechanisms of inhibition by Fe, Cr and Ni

Spectrophotometric determination of aliphatic amines by acylation with cinnamic anhydride

Analytical Chemistry of Fluorine and Fluorine-containing Compounds

Contact Info

Product

Resources

About