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Chemistry in Wastewater Treatment
Published in Sreedevi Upadhyayula, Amita Chaudhary, Advanced Materials and Technologies for Wastewater Treatment, 2021
Sonali Sengupta, Chandan Kumar Pal
Chemical oxidation of polluted water treatment involves an oxidative chemical process to chemically convert the Contaminants (plural) via oxidation and lower their concentrations in the polluted water. Oxidizing agents oxidize the pollutants, whereby these yield less-hazardous by-products or end products that can be separated or removed and thus produce water with improved quality in terms of contaminants. It has been under review for over two decades (27, 28). In this method, chemical oxidants are used for the oxidation of reduced inorganic species such as ferrous iron, Fe(II); manganous manganese, Mn(II); or the like and hazardous synthetic organic compounds. Apart from the removal of the contaminants, these are also effective in removing odor and color and in restoring tastelessness, which is a primary property of pure water. Another benefit is the removal of bio-contaminants, thereby lowering BOD. The most common oxidant in use is chlorine, in its elementary and various oxidized forms such as hypochlorite or chlorine dioxide; others are permanganate, ozone, etc. Use of several of these in combination with various forms of energy in terms of irradiation of UV or ultrasound produces strong oxidants, which are discussed in Section 7.6, “Advanced Oxidation.”
The Flow of Energy in the Biological World
Published in Jean-Louis Burgot, Thermodynamics in Bioenergetics, 2019
Recall (see Chapter 27) that dioxygen may not be necessarily the reactant in order to carry out an oxidation reaction. The part played by dioxygen in an oxidation reaction is nothing other than a particular case of a general group of chemical reactions, precisely those named “oxidation reactions”. Oxidizing agents are substances which are electron acceptors whereas reducing agents are electron donors (Cf Chapter 27).
Remedial Actions
Published in Benjamin Alter, Environmental Consulting Fundamentals, 2019
For metals that are toxic in their lowest valence states, the goal of in situ metals remediation is to take the metal out of solution through precipitation (see Section 9.2.3). Precipitation of metals can be stimulated by manipulating pH and creating either oxidation or reduction conditions to precipitate the metal contaminants. Typical oxidizing agents include potassium permanganate, hydrogen peroxide, hypochlorite and chlorine gas. Typical reduction reagents include alkali metals, such as sodium and potassium, sulfur dioxide, sulfite salts, and ferrous sulfate.
Degradation of ammonia from gas stream by advanced oxidation processes
Published in Journal of Environmental Science and Health, Part A, 2020
Kamila Kočí, Martin Reli, Ivana Troppová, Tomáš Prostějovský, Radim Žebrák
Probably the most widely used physical method for reduction of ammonia is wet scrubbing. It is very effective due to the good contact of purged gas and water, with addition of acid to the water it can remove over 90% of ammonia,[3] but its efficiency toward removal of other chemicals causing odor emissions depends on their solubility in water.[4] Another solution is using filters, most commonly filled with active carbon, that are used in two-column system where one column is adsorbing whereas the other is used for regeneration.[5] Oxidation can be named from the range of chemical methods. Ozone, potassium permanganate, chlorine, chlorine peroxide etc. can be used as and oxidizing agents. From these chemicals ozone is the most commonly used for its high reactivity.[6]
Sludge Pre-Treatment through Ozone Application: Alternative Sludge Reuse Possibilities for Recirculating Aquaculture System Optimization
Published in Ozone: Science & Engineering, 2019
Desislava Bögner, Frederike Schmachtl, Björn Mayr, Christopher P. Franz, Sabine Strieben, Gregor Jaehne, Kai Lorkowski, Matthew J. Slater
An alternative to enhance biodegradability, solubilize, or eliminate solid wastes and breakdown organic and inorganic compounds is the use of oxidizing agents like ozone (O3) and hydrogen peroxide (H2O2). Advanced oxidation processes (AOPs), chemical processes commonly used for wastewater and drinking water treatment, make use of oxidizing agents or their combination with techniques leading to the formation of highly reactive oxygen species (e.g., hydroxyl radicals), at a sufficient concentration to enable a non-selective reaction with organic and inorganic compounds and finally their mineralization (Oturan and Aaron 2014). These kinds of treatments also reduce or eliminate bacterial loads of water samples. Among the methods and techniques used in combination with oxidizers, UV irradiation, Fenton, photo-Fenton, semiconductor photocatalysis, electrolysis, sonication, and wet air oxidation have been successfully used for water/wastewater treatment (Antonopoulou et al. 2014; Oturan and Aaron 2014) and some have been tested at lab-scale for compounds removal and disinfection purposes in aquaculture facilities to lower the incidence of illness and off-flavor compounds and to improve the water quality (Brazil 1997; Klausen and Grønborg 2010; Nam-Koong et al. 2016; Pedersen and Pedersen 2012; Yao et al. 2017). Ozonation has been used to increase anaerobic digestion of waste-activated sludge for wastewater treatment with promising results in terms of increasing the soluble COD (Silvestre et al. 2015), but excluding disinfection purposes, there is a gap on the use of ozone in aquaculture facilities.
Recent developments and potential advancement in the kinetics of catalytic oxidation of glycerol
Published in Chemical Engineering Communications, 2020
Rozaini Abdullah, Syamima Nasrin Mohamed Saleh, Kartina Embong, Ahmad Zuhairi Abdullah
To overcome the limitation of biological processes and homogeneous catalytic reactions, researchers have developed various types of heterogeneous catalysts considering their interesting features like reusability, low corrosiveness, and the greener catalytic process that can reduce chemical wastes (Chen et al., 2014; Gholami et al., 2014; Okoye et al., 2017). Recently, researchers focused their attention to oxidation reaction because this process is environmentally friendly, able to produce high LA yield under mild conditions and the cost of oxidation agent is also low (Gil et al., 2011; Lakshmanan et al., 2013; Feng et al., 2014). Oxidation reaction is an ideal route to convert organic matters into carbon dioxide, gas, and water with the presence of oxidizing agents.