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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.
Selected Approaches for the Investigation of Microbial Interactions in Landfill Sites
Published in Eric Senior, Microbiology of Landfill Sites, 2020
Irene A. Watson-Craik, L. Robin Jones
Methanogenic fermentation of phenol has, however, been reported with inocula from anoxic aquifers24,25 and anaerobic digesters.26–28 It may be speculated that phenol plays a pivotal role in the methanogenic fermentation of a wide range of naturally occurring aromatic substrates since lignin monomers such as vanillate, ferulate, protocatechuate, and syringate have been shown to be dissimilated to catechol as an intermediate29,30 before oxidation to phenol, through cis-benzenediol.29p-Cresol and phenol have also been detected as intermediates in the methanogenic fermentation of the naturally occurring amino acid tyrosine.31 Since aromatic acids, such as vanillic, ferulic, and syringic, and amino acids, such as tyrosine, are likely to be widespread in waterlogged soils, sediments, and refuse, even if localized and at very low concentrations, it seems likely that the capability exists in the genetic pool for the degradation of phenol to CO2 and CH4. suboptimal degradation in landfills may be due, therefore, to excessive loading rates or to limiting environmental conditions.
Toxicology
Published in Martin B., S.Z., of Industrial Hygiene, 2018
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.
Effect of temperature on the physicochemical characteristics of pine nut shell pyrolysis products in a screw reactor
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Liyuan Qin, Ye Shao, Zhiwei Hou, Enchen Jiang
The bio-oil exhibited a very complex composition; thus, it was difficult to determine the elemental composition and heating value because of excess water. Wood vinegar as aqueous phase accounted for 21.03–28.42 wt.% of products, and the moisture content was as high as 85.3–90.1 wt.%. Table 4 presents the main ingredients of the wood vinegar obtained from PNS pyrolysis at 500°C. The main ingredients of the wood vinegar were phenols, ketones, ethers, esters, aldehydes, acids, alcohols, and amines. There were a total of 24 types of phenols in the wood vinegar, and 1,2-benzenediol, phenol, and 4-methyl-1,2-benzenediol were the main phenols. Other added-value compounds, such as vanillin and alcohols, were also present. Moreover, the wood vinegar also showed a lower pH of 2.6–3.2 and contained a large quantity of phenols and acids. The tar was the water-insoluble fraction of the bio-oil, which provides the main energy of the liquid product. The identified components of the tar with relative peak areas greater than 0.5% obtained from PNS pyrolysis at 500°C are listed in Table 5. The main ingredients of the tar included phenols, hydrocarbons, aldehydes, ketones, ethers, alcohols, amines, and acids. As shown in Table 5, 4-methylphenol and phenol were the main phenols. In addition, five types of organic compounds combined with an aldehyde group, representing 8.98%, and four types of organic compounds combined with nitrogen, representing 2.96%.
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]
Degradation of 2,4-dichlorophenol by cathodic microarc plasma electrolysis: characteristics and mechanisms
Published in Environmental Technology, 2022
Yifan Zhang, Jiahao Yu, Guijun Liu, Xiaoyue Jin, Ruihong Liu, Jiancheng Du, Wenbin Xue
On the basis of the above analyses, the possible 2,4-DCP degradation pathways by the CMPE method are shown in Figure 12. The pathways run in two parts in terms of the position of hydroxyl substituents. Most of 2,4-DCP is hydroxylated to become 4-chloro-1,2-benzenediol, 4-CP and hydroquinone, only a small part turns to 2-chloro-1,4-benzenediol, 2-CP and catechol. The polyhydroxy compounds have lower oxidation activation energy, which are easily oxidised to become benzoquinone. Then these molecules are decomposed to aliphatic carboxylic acids [23]. It is worth noting that there are not the ortho-hydroxyl substituents when using K2SO4 and KNO3 as electrolyte. These processes are similar to the electrochemical oxidation process.