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Repairing Nature
Published in Daniel T. Rogers, Environmental Compliance Handbook, 2023
Chemical oxidation involves the addition of an oxidizing agent to contaminated soil that either results in the complete destruction of the contaminants or can be used as a source of oxygen to more rapidly induce bioremediation as long as the correct dosage is used. This technology can be very effective at remediating many organic compounds, including some DNAPL compounds, as long as the correct dosages are applied and the chemicals can be delivered to the location where the contaminants reside in the subsurface. Common oxidizing agents used include (USEPA 2007): OzoneHydrogen peroxideSodium percarbonateSodium permanganatePotassium permanganateSodium persulphate
Remediation
Published in Daniel T. Rogers, Urban Watersheds, 2020
Chemical oxidation involves the addition of an oxidizing agent to contaminated soil that results in either the complete destruction of the contaminants or can be used as a source of oxygen to more rapidly induce bioremediation as long as the correct dosage is used. This technology can be very effective at remediating many organic compounds, including some DNAPL compounds as long as the correct dosages are applied and that the chemicals can be delivered to the location where the contaminants reside in the subsurface. Common oxidizing agents used include (USEPA 2007): OzoneHydrogen peroxideSodium percarbonateSodium permanganatePotassium permanganateSodium persulfate
General Types of Contaminated Site Restoration Methods and Technologies
Published in Kofi Asante-Duah, Management of Contaminated Site Problems, 2019
In situ chemical oxidation (ISCO) refers to a general group of specialty remediation techniques or technologies in which chemical oxidants are delivered to the subsurface to rapidly degrade organic contaminants, with each variant technology representing unique combinations of oxidants and delivery techniques. Broadly speaking, it involves the application of a strong oxidizing agent in the ground via well injection or a specially designed injection tool. The oxidants degrade the target contaminants by converting them to benign compounds, usually H2O, CO2, and mineral salts. Specific primary oxidants commonly used for ISCO include hydrogen peroxide (H2O2); Fenton’s reagent (i.e., an iron-catalyzed hydrogen peroxide—a liquid composed of Fe2+ + H2O2); permanganate (MnO4−)—typically potassium and sodium permanganate (usually, KMnO4 in liquid form); and ozone (viz., O3 gas). Each oxidant chemical is generally uniquely effective for different contaminants.
Current status of soil and groundwater remediation technologies in Taiwan
Published in International Journal of Phytoremediation, 2021
ISCO is another alternative technology to remediate soil or groundwater of several organic compounds. The contaminants are catalyzed by injecting liquid or gaseous oxidants directly into the polluted medium. The objective of this technology is to degrade, detoxify, or change the solubility of organic compounds. Furthermore, ISCO can be used as pretreatment and coupled with another treatment technology such as bioremediation. Fenton’s reagent, ozone, permanganate (sodium permanganate and potassium permanganate) and persulfate are mostly used as oxidants.
The chemical identity of “[Ag(py)2]MnO4” organic solvent soluble oxidizing agent and new synthetic routes for the preparation of [Ag(py)n]XO4 (X = Mn, Cl, and Re, n = 2–4) complexes
Published in Journal of Coordination Chemistry, 2018
István E. Sajó, Gréta B. Kovács, Tibor Pasinszki, Petra A. Bombicz, Zoltán May, Imre M. Szilágyi, Anna Jánosity, Kalyan K. Banerji, Rajni Kant, László Kótai
Caution: Perchlorate, permanganate, and nitrate salts of metal organic complexes are potentially explosive and should be handled with great care. Reagent grade silver(I) nitrate, sodium sulfate, sodium perrhenate, pyridine, sodium perchlorate, sodium permanganate, and potassium permanganate were supplied by Deuton-X Ltd., Hungary.
Oxidizing-gas-based passivation of pyrophoric iron sulfides
Published in Chemical Engineering Communications, 2021
Zhan Dou, Shuoxun Shen, Juncheng Jiang, Zhirong Wang, Xu Diao, Qiang Chen
Generally, the chemical compositions of pyrophoric iron sulfides generating under different circumstances are distinctive. For example, different from that in a distillation column, the formed iron sulfides in a typical closed natural gas pipeline mainly consist of mackinawite, greigite, and pyrites, and all these iron sulfides pose a risk of pyrophoricity. To lower the self-heating risk of pyrophoric iron sulfides when they come into contact with air during shutdowns and openings of equipment, cleaning with liquid solutions are typically employed currently as follows (Kang et al. 2016; Ustamehmetoğlu et al. 2013; Horsup et al. 2010; Yan et al. 1999; Wolthers et al. 2007; Hamdy et al. 2007; Sosa et al. 2003; Gander et al. 2002; Thomas et al. 1998).Acid cleaning with corrosion inhibitors and hydrogen sulfide suppressants is performed. The corresponding cleaning and treating are effective and inexpensive, but there are two shortcomings: 1) the acid that is used to dissolve iron sulfides scale, and the released hydrogen sulfide gas requires extra disposal and 2) the potential synergistic corrosion of the acid and hydrogen sulfide gas on steel appears to be serious.Chelating solutions are often used as cleaning agents. Several types of synthesized chelating solutions have mild or high pH values and can dissolve pyrophoric iron sulfides effectively without any emission of hydrogen sulfide gas; however, such solutions are often expensive. Moreover, additional costs are incurred in handling the residual chelating solutions.Oxidizing chemicals, especially permanganates, are used as cleaning agents. Oxidizing chemicals convert iron sulfides to oxides. Typically, up to now, permanganates, particularly potassium and sodium permanganate, have been extensively used to oxidize pyrophoric iron sulfides. However, permanganates must be injected into the treated equipment with a water rinse owing to its inapplicability in a pH-low environment, and then, a series of chemical cleaning procedures are also needed to dispose of the residual MnO2. Moreover, potassium permanganate treatment is more expensive than that of acid cleaning with corrosion inhibitors and hydrogen sulfide suppressants and more expensive than traditional cleaning with oxidizing agents, such as sodium hypochlorite and hydrogen peroxide.