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Carbon Nanomaterial Embedded Membranes for Heavy Metal Separation
Published in Shrikaant Kulkarni, Iuliana Stoica, A.K. Haghi, Carbon Nanotubes for a Green Environment, 2022
Pallavi Mahajan-Tatpate, Supriya Dhume, Yogesh Chendake
These heavy metals affect adversely to humans, animals, plants, and soil. It is necessary to separate them from groundwater and effluent to avoid contamination and accumulation/deposition. Apart from this, they are industrially important. Chromium is industrially used in the textile industry, leather tanning, metal finishing industry, and electroplating industry. Whereas to prepare nickel-cadmium batteries, Cd-Te solar cells and pigments, and in steel and plastic industries cadmium is used.9 Arsenic trioxide is useful in the treatment of leukemia, the mercurous oxide is antibacterial, antiseptic, and used in skin ointment, gold used as tonic and is anti-infective, detoxicant, and has antiaging properties.10
Ecological and Health Implications of Heavy Metals Contamination in the Environment and Their Bioremediation Approaches
Published in Ram Naresh Bharagava, Sandhya Mishra, Ganesh Dattatraya Saratale, Rijuta Ganesh Saratale, Luiz Fernando Romanholo Ferreira, Bioremediation, 2022
Trivalent chromium is an essential micronutrient, whereas hexavalent chromium is toxic to both humans and animals. Toxicity of chromium is found in people who live in areas close to waste disposal sites and chromium manufacturing industries. Chromium enters through respiratory tract in workers who work in leather, steel and textile industries and causes shortness of breath, coughing and wheezing. Allergic reactions such as skin rash occur in people using products containing chromium from leather and textile industries. Acute chromium toxicity leads to respiratory tract and skin inflammation, upset of gastrointestinal tract, coma, renal failure, cardiovascular diseases, teratogenicity, carcinogenicity and haematological effects (Douglas 2018).
X-Nuclei MRI and Energy Metabolism
Published in Guillaume Madelin, X-Nuclei Magnetic Resonance Imaging, 2022
Many trace elements also play important metabolic roles in the body, while some others have no known function or appear to be toxic. Iron (Fe) is a component of hemoglobin used to transport oxygen to cells. Lithium (Li) seems to have no biological role, but it has an effect as a drug for some psychiatric pathologies. Fluorine (F) is found in teeth and bones. Zinc (Zn) is the key component of many enzymes, and in hormone insulin. Copper (Cu) is an electron donor in many redox biochemical reactions. Iodine (I) is important for the synthesis of thyroid hormones that regulate metabolic rate and multiple cellular functions. Selenium (Se) is essential for the function certain enzymes, to stimulate metabolism and protect against free radical oxidants and some heavy metals. Chromium (Cr) interacts with insulin and has a role in glucose metabolism. Manganese (Mn) is essential for the function of certain enzymes, in particular those that protect mitochondria from oxidants. Molybdenum (Mo) is important for transforming sulfur into a usable form and for nitrogen fixation. Cobalt (Co) is an important component of vitamin B12, which is involved in protein formation and DNA regulation. Gold (Au) plays a role in preserving joints. Aluminum (Al) may be involved in the action of enzymes.
Assessing the impact of lime on chromium migration in soil caused by basic chromium sulfate in tannery
Published in Environmental Technology, 2023
Li-jie Song, Yu-hui Xu, Jin-yan Yang
Chromium (Cr) is one of the main pollutants in leather industry [1]. To date, Cr has received widespread attention due to its wide range of uses and adverse effects on the biological health and environmental security [2]. In the production of final leather products using raw hide or skin in tanneries, only 20% of the raw materials are eventually converted into leather-final products, while more than 60% of Cr enters the environment in the form of liquid and solid waste [3]. Cr exists in the environment mainly as Cr(III) and Cr(VI). Cr(III) is easily precipitated and has relatively low toxicity, while Cr(VI) is water-soluble and toxic [4–6]. Chromium can cause serious adverse effects on human health such as skin irritations, ulcers, diarrhoea and lung carcinoma [7–9]. Cr (VI) has been recognised as one of the chemical substances that pose a threat to human beings according to the US Environmental Protection Agency [10]. Basic chromium sulfate (BCS) is a primary Cr chemical used in the tannery industries. Although the increasing emphasis is placed on wet-white (chrome free) manufacture, Cr chemicals are still used in 80%−90% of tanneries worldwide [11], and the annual consumption of BCS can reach 40,000 t [6]. Previously, the lack of appropriate Cr disposal facilities and operations in most industries led to discharged casually of relevant wastes on land [2,12].
Chicken feathers derived materials for the removal of chromium from aqueous solutions: kinetics, isotherms, thermodynamics and regeneration studies
Published in Journal of Dispersion Science and Technology, 2022
Rupa Chakraborty, Anupama Asthana, Ajaya Kumar Singh, Renu Verma, Sreevidya Sankarasubramanian, Sushma Yadav, Sónia A. C. Carabineiro, Md. Abu Bin Hasan Susan
Chromium is noxious due to its non-biodegradable nature and it is present in the list of top 20 contaminants and hazardous materials in the last 15 years.[3,4] It can be found in the environment mainly in the Cr(III) and Cr(VI) valence states. Toxicity of trivalent chromium is negligible, but the hexavalent form of chromium is 500 times more toxic and carcinogenic than trivalent chromium.[5] The increased use of chromium in industrial applications, such as electroplating, metallurgy, tanning, textile dyeing, and preservation of food, poses serious threats to ecosystems. Cr(VI) exists in different anionic forms such as hydro chromate (HCrO4−), chromate (CrO42–), or dichromate (Cr2O72–) anions, which depend on the pH of aqueous solution. Cr(VI) ions are structurally similar to oxy-anions, viz. phosphates and sulfates and they can actively enter inside the cell.[6] It causes cancer in the digestive tract, headache, diarrhea, nausea, vomiting, lung tumor, and hemorrhage. When Cr(VI) ions enter inside the cell, they form stable bonds with protein and DNA. This can show several mutagenic effects such as genotoxicity and mutagenicity.[6] The Environmental Protection Agency (EPA) set the allowed limit of chromium in drinking water as 0.1 mg/L.[7]
Cr(VI) adsorption on low-cost activated carbon developed from grape marc-vinasse mixture
Published in Particulate Science and Technology, 2020
Hasan Arslanoğlu, Semih Kaya, Fikret Tümen
In aqueous solutions, chromium commonly exists in two stable oxidation states, Cr(III) and Cr(VI), which have different characteristics. Trivalent chromium is considered to be a trace element essential for the proper functioning of living organisms and it is toxic at high concentrations. Hexavalent chromium is known to be toxic and carcinogenic, affecting immune, urinary and respiratory systems and causing various illness and cancers. The USEPA has a drinking water standard of 100 μg/L for total chromium, which includes all forms of chromium including Cr(VI)(USEPA 2012). According to European regulations (Anonymous 1980), the maximum concentration of total chromium in drinking water was set as 50 μg/L. Accordingly, chromium, especially Cr (VI), should be regarded as a dangerous contaminant and remedies for its removal from water must be explored.