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Technical Equipment for Crystal Layer Growth
Published in Gerard F. Arkenbout, Melt Crystallization Technology, 2021
The purity requirements for monochloroacetic acid are high, especially when the material is used for the manufacture of cellulose ethers and insecticides. Good results are obtained with melt crystallization, using the equipment ment according to Figure 11.1. The tubes of the heat exchanger are made of polypropylene because of the very corrosive properties of monochloroacetic acid (Rittner and Steiner, 1985). A production capacity of 35,000 tons per year was needed. This capacity was attained using a number of crystallizers, with a total volume of about 400 m3. Every separate crystallizer contains a set of about 100 heat exchanger tubes being mounted at the top plate of the crystallizer vessel and connected with a circulating water system to heat or cool the crystallizer contents. The feed contains about 5% dichloroacetic acid and 1% acetic acid as impurities. The product purity is at least 99.5%. The melting point of the pure compound is 63°C.
Fundamental Aspects
Published in Bruno Langlais, David A. Reckhow, Deborah R. Brink, Ozone in Water Treatment, 2019
Guy Bablon, William D. Bellamy, Marie-Marguerite Bourbigot, F. Bernard Daniel, Marcel Doré, Françoise Erb, Gilbert Gordon, Bruno Langlais, Alain Laplanche, Bernard Legube, Guy Martin, Willy J. Masschelein, Gilbert Pacey, David A. Reckhow, Ciaire Ventresque
Using an aquatic fulvic acid, Reckhow et al. (1986) showed that ozonation at a neutral pH (phosphate buffer solution) decreased the formation potential of chloroform, total organic halides (TOX), trichloroacetic acid, and dichloroacetonitrile. Nevertheless, the formation potential of dichloroacetic acid and of trichloroacetone may increase, together with the chlorine consumption potential. Through an addition of bicarbonate ion in the solution to be ozonated, the same experiments will lead systematically to a better result, whatever the parameter analyzed. Figure II–37 illustrates the case of chloroform and TOX compounds.
A Systematic Approach to Monoprotic Acid-Base Equilibria without and with Correction for Ionic Strength
Published in Harry L. Pardue, Chemical Equilibria, 2018
In a titration of a weak acid such as dichloroacetic acid with sodium hydroxide, it is desirable that all the acid be converted to the conjugate base at the equivalence point, i.e., that α0 → 0.0 and that α1 → 1.0. For example, let's compare fractions of dichloroacetic acid converted to dichloroacetate at the equivalence point for the titration of 25 mL 0.10 M dichloroacetic acid with 0.10 M sodium hydroxide without and with 0.10 M acetic acid.
Electrochemical reduction of halogenated organic contaminants using carbon-based cathodes: A review
Published in Critical Reviews in Environmental Science and Technology, 2023
Jacob F. King, William A. Mitch
Both hydrodehalogenation and β-elimination reductive dehalogenation pathways involve cleavage of carbon-halogen bonds to form halide products. During reductive electrochemical treatment of halogenated methanes, ethanes and other DBPs, yields of halides were >70% relative to the initial total halogens within the degraded compounds (Fernández-Verdejo et al., 2021; Y. Li et al., 2016; Y. Li et al., 2016; Radjenović et al., 2012). The higher yields of bromide and iodide than of chloride indicated that cleavage of C-Br and C-I bonds was favored over cleavage of C-Cl bonds. Complete dechlorination can be challenging. For example, electrochemical reduction of trichloroacetic acid to acetic acid using reduced graphene oxide (rGO) cathodes at −0.85 V/SHE proceeded through dichloroacetic acid and monochloroacetic acid intermediates (Mao et al., 2018). Although the chloride yield reached ∼35% after 1 h, the chloride yield increased to only 70-90% after 3 h with monochloroacetic acid still present at ∼30% yield (Mao et al., 2018). The accumulation of halogenated organic intermediates indicates a lag between loss of the parent compound and full release of the constituent halogens as halides.
Effectiveness of Bio-Activated Carbon Filtration and Ozonation on Control of Halo Acetic Acids Formation during Chlorination of Ganga River Water at Kanpur, India
Published in Ozone: Science & Engineering, 2020
Nagasrinivasa Rao Naladala, Rambabu Singh, A.S. Venkatesh, P. Bose, Prasad Babu K, I. D. Narayan
Analytical reagent grade chemicals, high-purity gasses, deionized water from a Milli-Q system (Millipore, USA), 1 −2 dibromopropane and haloaceticacid mix (200 ppm), Methyl-tertiary-butyl-ether (MTBE) (HPLC grade, >99% purity), Methanol (HPLC grade, >99% purity), Copper-II-sulfate-V hydrate (>99% purity), Sodium sulfite (>98% purity), Anhydrous sodium sulfate (99.5% purity), Sodium bicarbonate (99.5% purity), Aluminum sulfate, Al₂ (SO4)3.18H2O (purity 99%), and neat compounds (>99% purity) of nine HAAs named monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), monobromoaceticacid (MBAA), dibromoacetic acid (DBAA), tribromoacetic acid (TBAA), chlorobromo acetic acid (CBAA), dichlorobromoacetic acid (DCBAA), and dibromochloroacetic acid (DBCAA) were used in this experiment.
Bioprospecting of potential petroleum hydrocarbon degraders using bacterial strains isolated from soils around transformer installation areas
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Nkem Torimiro, Godswill E. Akhigbe, Festus M. Adebiyi
The chromatogram of the media containing Providencia stuartii (Figure 4) revealed the presence of the following organic acids (retention time, min): 2-propenoic acid, 3-(dimethylamino)-3-(1-piperidinyl)-, methyl ester (19.875); 3-quinolinecarboxylic acid, 6,8-difluoro-4-hydroxy-, ethyl ester (20.688). The chromatogram of the media containing Providencia rettgeri (Figure 5) showed the presence of the following organic acids (retention time, min): [2-methyl-4-(piperidine-1-sulfonyl)phenoxy]acetic acid, methyl ester (6.269), and dichloroacetic acid (10.679).