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Phenols
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Global Resources and Universal Processes, 2020
Leszek Wachowski, Robert Pietrzak
Phenols and their derivatives are common in the natural environment. These compounds are used as the component of dyes, polymers, drugs, and other organic substances. The presence of phenol substances in ecosystems is also related with production and degradation of numerous pesticides and the generation of industrial and municipal sewages. Some phenols are also formed during natural processes. These compounds may be substituted with chlorine atoms, nitrated, methylated, or alkylated. Both phenols and catechols are harmful ecotoxins.
Solvent Exposure and Toxic Responses
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
Phenols are aromatic hydrocarbons with one or more hydroxyl groups attached to the benzene ring. The simplest of the compounds is phenol, which contains only one hydroxyl group on a benzene ring. Other examples include cresol (methyl phenol), catechol (1,2-benzenediol), resorcinol (1,3-benzenediol), and hydroquinone (1,4-benzenediol). Phenol is used as a cleaning agent and disinfectant, but its primary use is as a chemical intermediate for resins and pharmaceuticals. Cresol is used primarily as a disinfectant. Catechol is used in photography, fur dying, leather tanning, and as a chemical intermediate. Resorcinol is used as a chemical intermediate for adhesives, dyes, and pharmaceuticals. Hydroquinone is used in photography, as a polymerization inhibitor, and as an antioxidant.
Nanocatalysts Based in Zeolites for Environmental Applications
Published in Vanesa Calvino-Casilda, Antonio José López-Peinado, Rosa María Martín-Aranda, Elena Pérez-Mayoral, Nanocatalysis, 2019
Isabel Correia Neves, António M. Fonseca, Pier Parpot
These metal pyrrolyl-azine complexes encapsulated in the zeolite NaY exhibited increased activity for the phenol oxidation, in the presence of tBuOOH as an oxygen source, under mild conditions, compared to the homogeneous systems. The heterogeneous nanocatalysts were achieved by two different methodologies reported in the literature (Kuźniarska-Biernacka et al. 2013b; Kuźniarska-Biernacka et al. 2012c). In this context, the heterogeneous nanocatalysts were prepared by two steps: introduction of metals by ion exchanged into zeolite followed by in situ complexation with the pyrrolyl-azine derivative (L, ligand). The prepared catalysts showed high conversion for the phenol oxidation under optimized reaction conditions with 100% selectivity towards catechol.
Colorimetric paper bioassay by horseradish peroxidase for the detection of catechol and resorcinol in aqueous samples
Published in Preparative Biochemistry & Biotechnology, 2020
Ajinkya Dabhade, Sivaraman Jayaraman, Balasubramanian Paramasivan
Catechol is an ortho-isomer of benzenediol also called pyrocatechol and has many applications as a polymerization inhibitor, photographic developer, lubricating oil and in pharmaceuticals.[1] It is a toxic and persistent water pollutant in the environment.[2,3] Catechol is classified as a possible carcinogen to humans (group 2 B) by the International Agency for Research on Cancer (IARC).[4] Phenolic compounds such as catechol have been listed as priority pollutants by EPA.[5–7] It is toxic for most aquatic animals including fish at lower concentrations.[8] Resorcinol is a meta isomer of benzenediol widely used in the manufacturing of phenolic resins and pharmaceuticals.[9] The rubber industry highly consumes resorcinol (50%) with a 0.1% loss during tire production. About 25% resorcinol usage is for high-quality wood bonding applications and other uses are in the manufacturing of pharmaceuticals, dyes, hair dye formulations and pesticides .[10] Resorcinol is an endocrine-disrupting chemical, which can cause a serious impact on wildlife on release to the environment.[11] Coal carbonization and gasification industries are a major source of catechol and resorcinol in wastewater where its concentration ranges from a few mg/L to a maximum of 2000 mg/L.[9,12]
Oxidation-precipitation of magnetic Fe3O4/AC nanocomposite as a heterogeneous catalyst for electro-Fenton treatment
Published in Chemical Engineering Communications, 2020
Pegah Nazari, Neda Askari, Shahrbanoo Rahman Setayesh
The treatment of the agricultural and industrial effluents which are containing toxic and low or non-biodegradable compounds has become the most challenging issue in the environmental protection science. It is necessary to eliminate these hazardous compounds completely before discharging them into the environment. A considerable portion of water pollutants is organic compounds. The phenolic pollutants are removed hardly due to their high stability. Catechol is a phenol-derived compound with high stability and toxicity. This aromatic compound is mostly utilized as a precursor to flavors, fragrances, and pesticides (Cavalieri et al., 2002). Catechol caused some diseases such as methemoglobinemia, DNA disruption, cyanosis, and death (Cavalieri and Rogan, 2004). Regarding the harmful impact of catechol on human health, an innovative and effective method is required before discharging it into the water resources. The organic chemicals are not remediated effectively by conventional wastewater treatments, due to their drawbacks like time-consuming, inefficiency, creating more toxic intermediates or products, and the need for secondary remediation process. These traditional techniques are categorized as adsorption, photocatalysis, sonochemical, ozonation, and biodegradation (Huang et al., 2017; Alam et al., 2018; Chadi et al., 2018; Ren et al., 2018; Yang et al., 2018).
Engineered Pseudomonas putida for biosynthesis of catechol from lignin-derived model compounds and biomass hydrolysate
Published in Preparative Biochemistry & Biotechnology, 2022
Catechol and its derivatives are important chemical precursors for several applications such as carbamate insectidices (carbofuran and propoxur), polymerization inhibitors (4-tert-butylcatechol), photographic developers, tanning agents, perfumes, cosmetics, biomaterial and therapeutic agents.[1,2] Annually, 2.5 × 107 kg of catechol is produced commercially by synthetic/chemical routes.[3] The various chemical routes for catechol production include hydrolysis of 2-chloro phenol with copper as a catalyst at elevated temperature; hydroxylation of phenol in presence of peroxide along with catalyst; dehydrogenation of 1,2-cyclohexanediol with palladium as a catalyst at 300 °C; and oxidation of salicylic aldehyde and demethylation of guaiacol.[1,4,5] Chemical synthesis of catechol is a catalyst-based energy intensive process, resulting in the co-production of compounds such as hydroquinone and resorcinol. This compound along with un-reacted phenol mixtures makes separation and scale up a tedious job.[1,6,7] Moreover, catechol is derived from petroleum-based feedstock leading to several environmental issues thereby necessitating focusing our attention toward catechol synthesis from sustainable and renewable starting material using microbes.[3,8] Lignocellulosic biomass is one such sustainable and renewable feedstock giving rise to bio-refinery concept.