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Industrial Ecology for Waste Minimization, Utilization, and Treatment
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Biodegradation of wastes is a term that describes the conversion of wastes by enzymatic biological processes to simple inorganic molecules (mineralization) and, to a certain extent, to biological materials. Usually, the products of biodegradation are molecular forms that tend to occur in nature and that are in greater thermodynamic equilibrium with their surroundings than are the starting materials. Detoxification refers to the biological conversion of a toxic substance to a less toxic species. Microbial bacteria and fungi possessing enzyme systems required for biodegradation of wastes are usually best obtained from populations of indigenous microorganisms at a hazardous waste site where they have developed the ability to degrade particular kinds of molecules. Biological treatment offers a number of significant advantages and has considerable potential for the degradation of hazardous wastes, even in situ.
The State of the Science: Human Health, Toxicology, and Nanotechnology Risks
Published in Jo Anne Shatkin, Nanotechnology, 2017
When a person is exposed to a chemical, toxicity is dependent on the chemical entering the body, being metabolized, and then excreted. The process of a chemical entering the body is called absorption. Common routes of absorption include ingestion, inhalation, and dermal penetration. Other routes, such as intraperitoneal, intravenous, and intra-arterial, are more commonly associated with medicines than with environmental agents. Once in the body, chemicals are often distributed, meaning that they are transported between locations in the body. Chemicals that enter the body are often metabolized. Metabolism generally makes a chemical less toxic; however, there are a number of cases where metabolism makes a chemical more toxic before it detoxifies. The primary organ of detoxification is the liver. Finally, most chemicals are released from the body by the process called excretion. The most common excretion path is in urine, via the kidneys. Other pathways of excretion are known and include intestinal release, release from the lungs, and release from the skin. Taken together, the absorption, distribution, metabolism, and excretion (ADME) information of a chemical describes how it moves through the body; it is thus important to understand the ADME properties of nano-objects.
Industrial Ecology for Waste Minimization, Utilization, and Treatment
Published in Stanley Manahan, Environmental Chemistry, 2017
Biodegradation of wastes is a term that describes the conversion of wastes by enzymatic biological processes to simple inorganic molecules (mineralization) and, to a certain extent, to biological materials. Usually, the products of biodegradation are molecular forms that tend to occur in nature and that are in greater thermodynamic equilibrium with their surroundings than are the starting materials. Detoxification refers to the biological conversion of a toxic substance to a less toxic species. Microbial bacteria and fungi possessing enzyme systems required for biodegradation of wastes are usually best obtained from populations of indigenous microorganisms at a hazardous waste site where they have developed the ability to degrade particular kinds of molecules. Biological treatment offers a number of significant advantages and has considerable potential for the degradation of hazardous wastes, even in situ.
Histopathological alterations in Van fish (Alburnus tarichi Güldenstädt, 1814) exposed to tebuconazole
Published in Chemistry and Ecology, 2022
Elif Kaval Oğuz, Burcu Ergöz, Ahmet R. Oğuz
In fish, gills are the principal site of body fluid pH regulation and nitrogenous waste excretion [16,17]. Gills are open directly to the outside of the body. For this reason, all changes that occur in the external environment affect the gills, and especially the effects of toxic substances cause many histopathological effects on the gills [18,19]. These changes have been used by many researchers as bioindicators in the assessment of water quality [20]. The liver and kidneys are organs involved in detoxification. The liver separates toxic substances into their metabolites and deactivates them as a result of the enzymes that they contain, and some of these chemicals are deposited into the tissue [21]. The kidneys are involved in the removal of toxins from the body and also in osmoregulation. Like the gills, many lesions may develop in the liver and kidneys as a result of detoxification [22].
Oxidative and genotoxic effects of bisphenol A on primary gill cell culture of Lake Van Fish (Alburnus tarichi Güldenstädt, 1814)
Published in Chemistry and Ecology, 2018
Elif Kaval Oğuz, Okan Arihan, Ahmet R. Oğuz
In this study, total antioxidant level was not different from the control group (Figure 3(B)). Li et al. reported that BPA had no effect on CAT and SOD levels but increased GST levels [22]. Liver is a basic organ where detoxification of harmful substances occurs in vertebrates. Compared to antioxidant enzyme levels in the liver and gills, it is approximately 10–100 times higher than the gill in the liver [23]. A significant difference was observed between 10−7 and 10−5 M at the end of 48 h, but this difference is insignificant when compared to the control group. During primary gill cell isolation, the cells were treated either mechanically (trituration) or enzymatically (trypsin). Both the enzymatic and the mechanical processes may have affected the antioxidant enzymes in the control group. These effects may have caused the difference between the BPA groups and the control groups to be insignificant.
Endocrine disrupting chemicals (EDCs): chemical fate, distribution, analytical methods and promising remediation strategies – a critical review
Published in Environmental Technology Reviews, 2023
Mridula Chaturvedi, Sam Joy, Rinkoo Devi Gupta, Sangeeta Pandey, Shashi Sharma
Physical methods are commonly used as the operation is simple based on particle-size distribution of pollutants. These prove to be useful in separating hazardous chemicals from non-hazardous waste stream without the alteration of their chemical structures. It provides an advantage of removal of chemicals for further detoxification by chemical or biological treatments. The limitations of physical methods include multistep operation as the pollutant removed is subjected to further processing, thereby increasing the processing cost [50]. Adsorption, membrane filtration, nano-filtration or ultrafiltration and reverse osmosis are examples of physical methods applicable for EDCs removal.