Wet oxidation is a process in which partial or complete oxidation reactions occur in a supercritical water medium. Supercritical water exhibits drastically enhanced solvent power toward both oxygen and hydrocarbons, therefore permitting oxidation reactions to be carried out in a nearly homogeneous phase. The selectivity of this partial destructive oxidation can be controlled by varying the process operating parameters, thereby creating a favorable environment for desired byproducts while simultaneously reducing unwanted products. The advantages of these types of processes include; no use of classical conventional catalyst, milder temperature conditions for certain applications, very short residence time, high selectivity, and in most cases a "near zero" discharge. The selective partial oxidation of chlorinated hydrocarbons (CHC) is discussed in this paper, with particular emphasis on the recovery of reaction byproducts for reuse or further processing.
ABSTRACT As a part of process engineering study of the perchloroethylene (PCE) coal desulfurization process, the minimization of residual chlorine content after the desulfurization process has been studied in detail. The residual chlorine in the coal is removed by a novel process, which involves the use of steam as the displacing agent. Steam, when passed through a bed of the PCE treated coal, washes away the residual solvent in coal. Two designs, viz. fluidized bed and packed bed steam strippers are discussed in detail. This paper presents the results of the design implementations and discusses the advantages and disadvantages of each design. It was found that the chlorine content of the coal treated in the packed bed steam stripper was not only decreased to a level lower than before steam stripping, but to a level lower than that of the raw samples before the PCE extraction.
This study investigates the antibacterial and antioxidant activities of the ethanol extract of Acer tegmentosum Maxim (EATM) against Staphylococcus aureus.The total polyphenol and flavonoid content, 1,1-diphenyl-2picryl hydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging effect, and reducing power of the ferric reducing antioxidant power (FRAP) method were measured to verify the antioxidant activity of the EATM.The antibacterial activity against S. aureus using the EATM was verified by the paper disc method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods.The total polyphenol and flavonoid contents were 266.66 μg GAE/mg and 6.46 μg QE/mg, respectively.The DPPH and ABTS radical scavenging activity showed a concentration-dependent scavenging activity.The RC 50 values of the EATM were 21.49 and 12.81 μg/mL, respectively.A FRAP analysis was conducted for evaluating the reducing power of the EATM and an efficacy of 0.73 ± 0.19 mM FeSO 4 E/mg was observed.The antibacterial activity of EATM against S. aureus, determined using the paper disc method, showed an inhibitory ring of 3 mm at 2 mg.The MIC was confirmed at a concentration of ≥ 16 mg/mL, while the MBC was confirmed at 32 mg/mL.As the EATM shows antioxidant and antibacterial activities against S. aureus, it can be used as an effective antidote against atopic dermatitis.
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