Articolul precedent |
Articolul urmator |
![]() |
![]() ![]() |
Ultima descărcare din IBN: 2023-12-06 02:01 |
![]() GONTA, Maria, LEONTIEVA, Elizaveta. Oxidation/mineralization of anionic sodium dodecyl benzenesulfonate surfactant by fenton reagent. In: Ecological chemistry ensures a healthy environment, 16 septembrie 2022, Chisinau. Chişinău: Institute of Chemistry, 2022, p. 12. DOI: https://doi.org/10.19261/enece.2022.ab03 |
EXPORT metadate: Google Scholar Crossref CERIF DataCite Dublin Core |
Ecological chemistry ensures a healthy environment 2022 | ||||||
Seminarul "Ecological chemistry ensures a healthy environment. " Chisinau, Moldova, 16 septembrie 2022 | ||||||
|
||||||
DOI:https://doi.org/10.19261/enece.2022.ab03 | ||||||
Pag. 12-12 | ||||||
|
||||||
![]() |
||||||
Rezumat | ||||||
Surfactants are the main ingredients of synthetic detergents. It is widely used in soap, toothpaste, cleaning detergents and shampoo. They also have numerous applications in industrial products, in cosmetics, medicines, textiles, food, paper, oil technology, paints, polymers, pesticides and mining. The composition of wastewater includes anionic and nonionic surfactants, which are the most difficult to biodegrade in natural waters, thus spilled into surface and underground waters, cause negative influences on the self-purification process. The global production of surfactants is 13 million tons per year, and anionic surfactants constitute the largest part of the total STAs used. The toxicity of linear alkyl sulfonates (ASLs) to fish and humans is quite high, since ASLs even at low concentrations (1 mg/L) can cause toxicity to aquatic organisms, which increases in proportion to the total carbon content of the alkyl chain. Therefore, due to their resistance to biodegradation, they can accumulate in aqueous environments and influence the quality of natural waters. In this context, the development of waste water decontamination methods is a fairly current issue. Various technological processes are used for the removal or degradation of surfactants, including the use of anaerobic fluidized bed reactors, chemical methods, electrochemical oxidation, membrane technology, chemical precipitation, and catalytic and photocatalytic degradation. However, the limitations of using biological methods and difficulties in using other technologies (such as membranes) require us to develop and use new methodologies to deal with these problems. Thus, advanced oxidation processes (AOPs) [1] are recommended for wastewater pre-treatment or tertiary treatment, when wastewater contaminants have high chemical stability and/or low biodegradability. By reason of scientific research, it was found that the degradation/mineralization performance of the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) depends on physico-chemical parameters such as pH value, hydrogen peroxide and catalyst concentration, and reaction time. As a result of the experimental studies, the degradation conditions of SDBS were determined. It was established that at optimal conditions of homogeneous oxidation ([H2O2]0=1·10-3 molL-1, [Fe2+]0=1·10-3 molL1, and pH value 3), the concentration of anionic surfactant in the system decreases from 20 mg/L to 7 mg/L, and the degradation performance can reach up to 74.4%. The reaction rate (Δc/Δt) of oxidation/mineralization is determined by the concentration of OH radicals formed on the surface of the catalyst and by the probability that OH radicals interact with surfactant molecules. So, the reaction rate of SDBS can reach 2.89·10-7 molL-1s-1, and the rate constant k=0.76·10-3 s-1 under optimal conditions. |
||||||
|