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Supramolecular Gels as Smart Sorbent Materials for Removal of Pollutants From Water
Published in Uma Shanker, Manviri Rani, Liquid and Crystal Nanomaterials for Water Pollutants Remediation, 2022
The presence of various toxic metal ions in concentrations above the permissible limits in water can have deleterious effects on human health (Chonamada et al. 2019). Metal ions such as Hg2+, Pb2+ and Cd2+ have a very strong binding affinity toward various biomolecules, which can lead to either modification in the activity of the biomolecules or their complete activity loss. Therefore, these toxic metal ions when consumed directly or indirectly above the permissible limits can cause severe diseases, including kidney failure, damage to the central nervous system and immune system (Aragay et al. 2011). Unfortunately, these hazardous metal ions are a constituent of industrial waste, which is discharged in water regularly. Supramolecular gels can be used to remove these metal ions via two different strategies. One of the strategies utilizes the coordination ability of the metal ions to bind to specific ligands leading to the formation of a metal-organic gel, hence effectively separating the toxic metal ions from water into the nanoscale gel network. The second strategy exploits the porous structure of supramolecular gels for the adsorption of these toxic metal ions into the matrix of the gel. Some of the examples of supramolecular gels for uptake and removal of toxic metal ions are discussed below:
Waste and Pollution
Published in John C. Ayers, Sustainability, 2017
Heavy metals are transition elements that are usually toxic. They are referred to as trace elements because they occur at low concentrations in the environment. Examples include lead, mercury, arsenic, cadmium, and selenium. Heavy metals are used in many products, and industrial processes and improper disposal have led to heavy metal pollution of the environment. The most common heavy metal exposure pathway is ingestion of drinking water, although other exposure pathways such as inhalation of atmospheric particles can present significant risk. Sustainability requires that we reduce risk by safely managing toxic metals and preventing them from contaminating our supporting ecosystems. Here we briefly examine health effects, identify products that often contain these metals, and discuss how to safely dispose of or recycle them.
Removal of Toxic Metals from Contaminated Water Using Powder Activated Alumina Combined with Coagulation/Flocculation
Published in Nada Assaf-Anid, Hazardous and Industrial Wastes Proceedings of the Thirty-Third Mid-Atlantic Industrial and Hazardous Waste Conference, 2001
One of the major factors affecting the potable water treatment industry is the presence of toxic metals in the natural source water. Toxic metals are defined as priority pollutants by the United States Environmental Protection Agency (USEPA) and must be removed from the water below stringent concentration levels prior to distribution as drinking water or released to a natural environment. As defined by the USEPA, toxic metals include: arsenic, barium, cadmium, chromium, copper, lead, mercury, and selenium. The removal of these toxins can prove to be difficult and costly with varied degrees of efficiency. Their small size and chemical composition make removal by current conventional water treatment processes unacceptable with proposed drinking water standards. Determining a process to effectively and cost efficiently remove these toxic metals is important to the safety and compliance of the water treatment industry.
Coal ash for removing toxic metals and phenolic contaminants from wastewater: A brief review
Published in Critical Reviews in Environmental Science and Technology, 2023
Abdelkader Labidi, Haitao Ren, Atif Sial, Hui Wang, Eric Lichtfouse, Chuanyi Wang
Recently, reports on residues removal from water and soil have evidenced that toxic metals can be considered as the top-list inorganic pollutants of water (Hasan et al., 2022; Helmrich et al., 2022; Li, Liu, et al., 2022; Luo et al., 2022; Zamora-Ledezma et al., 2021). Although some metals, for example, calcium (Ca), magnesium (Mn), zinc (Zn), iron (Fe), copper (Cu), and nickel (Ni), are necessary micronutrients in our body, they can be toxic for humans, plants and animals when taken up in high concentrations or in certain forms (Ayub et al., 2021; Glasner et al., 2021). Other toxic metals such as chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) are classified as poisonous compounds for humans even at low concentrations (Mukherjee et al., 2022; Sun et al., 2022). The main sources of heavy metals are fossil fuel combustion, metallurgical and agricultural production, mining, and industrial sectors, waste disposition as well as biomass combustion and coal burning for winter heating (Cui et al., 2022; Mukherjee et al., 2022; Sun et al., 2022).The bio-accumulation of toxic metals in plants and their discharge in water cause various illnesses like Parkinson’s diseases including olfactory dysfunction, constipation, sleeping disorder, tremor, rigidity, and bradykinesia (Vellingiri et al., 2022). In addition, the contamination of water with heavy metals may lead to cardiovascular diseases, renal, and urological diseases (Guo et al., 2022; Korashy et al., 2017).
Adsorption performance of activated carbon synthesis by ZnCl2, KOH, H3PO4 with different activation temperatures from mixed fruit seeds
Published in Environmental Technology, 2022
As a result of the advancement of nuclear energy, mining and chemical production, high levels of toxic heavy metal ions are released into the environment, creating grave dangers to underground and surface mediums [1–3]. The continuous exposure to heavy metal ions, high toxicity and accumulation in living organisms can cause the long-time health problems in humans and other types [4–6]. Therefore, it is essential to remove the heavy metal ions from the polluted water [7,8]. Water pollution is one of the most significant subjects to protect the environment. For human and living organisms, heavy metals such as Cr(III), Cd(II), As(III), Cu(II), Zn(II), Ni(II), Pb(II), are toxic and health hazards if their concentrations exceed the permissible limits [9,10]. The long-time exposure to toxic metals causes human health problems such as carcinoma, anaemia, liver and kidney injury. Nickel is a toxic metal and is known to be carcinogenic. According to the World Health Organization (WHO), Ni(II)and Cu(II) concentrations in aqueous solutions should be below 0.2 and 2 mg/L, respectively [11]. A high intake of copper into the human body can oxidize DNA, lipids and proteins inside the cell. Therefore, it can potentially cause cancer [12]. Oral exposure to Cr(III) in humans is due to contaminated water. Exposure to chrome causes indigestion, kidney failure mouth ulcers, abdominal pain, acute tubular necrosis, vomiting, and lung cancer [13]. For this reason, the toxic heavy metals should be taken from the water to keep human health and the perimeter [14].
Phytoremediation of metals by colonizing plants developed in point bars in the channeled bed of the Dilúvio Stream, Southern Brazil
Published in International Journal of Phytoremediation, 2022
Vinícius Maggioni dos Santos, Leonardo Capeleto de Andrade, Tales Tiecher, Robson Andreazza, Flávio Anastácio de Oliveira Camargo
The pollution of the water bodies by many substances discharged without treatment is another major problem in urban areas. Potentially toxic metals can have sources from domestic sewage, wastewater, road dust, solid urban waste, and atmospheric deposition. It causes concern about the harmfulness to human beings since toxic metals are not biodegradable and accumulate in organisms (Patidar et al. 2017). Many metals are essential for organisms; however, in excess, they are harmful to human health and the environment. Thus, the decontamination of polluted areas is a requirement for the environmental quality and sanitary safety of the population (Ali et al.2013; Sharley et al. 2016; Demarco et al. 2018). Some metals without vital functions are toxic to living organisms, even in small amounts; these metals are dangerous to human health and are increasing in the environment due to rapid urbanization and industrialization, and the intensive use of chemicals in agricultural activities (Jose and Ray 2018).