Selective Removal of Heavy Metal Ions from Waters and Waste Waters Using Ion Exchange Methods

Abstract

Ion Exchange Technologies 194gastrointestinal tract less than 10% cadmium is absorbed. An important source of human exposure to cadmium is food and water. In natural water its typical concentration lies below 0.001 mg/dm 3 , whereas, the upper limit recommended by EPA (Environmental Protection Agency) is less than 0.003 mg/dm 3 . The maximum limit in drinking water is 0.003 mg/dm 3 .Cadmium accumulates in kidneys, pancreas, intestines and glands altering the metabolism of the elements necessary for the body, such as zinc, copper, iron, magnesium, calcium and selenium. Damage to the respiratory tract and kidneys are the main adverse effects in humans exposed to cadmium compounds. In humans exposed to fumes and dusts chronic toxicity of cadmium compounds is usually found after a few years. The main symptom of emphysema is that it often develops without preceding bronchitis. The second basic symptom of chronic metal poisoning is kidney damage. It includes the loss and impairment of smell, pathological changes in the skeletal system (osteoporosis with spontaneous fractures and bone fractures), pain in the extremities and the spine, difficulty in walking, the formation of hypochromic anemia. The most known 'Itai-Itai' disease caused by cadmium exposure is mixed osteomalacia and osteoporosis. However, an important source of cadmium in soils are phosphate fertilizers. Large amounts of cadmium are also introduced to soil together with municipal waste. The high mobility of cadmium in all types of soils is the reason for its rapid integration into the food chain. Daily intake of cadmium from food in most countries of the world is 10-20 mg.Lead is a toxic metal, which accumulates in the vital organs of men and animals and enters into the body through air, water and food. According to the WHO (World Health Organization) standards, its maximum limit in drinking water is 0.05 mg/dm 3 but the maximum discharge limit for lead in wastewater is 0.5 mg/dm 3 . Its cumulative poisoning effects are serious haematological damage, anaemia, kidney malfunctioning, brain damage etc. Chronic exposure to lead causes severe lesions in kidney, liver, lungs and spleen.Lead is used as industrial raw material in the manufacture of storage batteries, pigments, leaded glass, fuels, photographic materials, matches and explosives. Lead being one of very important pollutants comes from wastewaters from refinery, wastewaters from production of basic compounds containing lead, wastewaters with the remains of after production solvents and paints. Large toxicity of lead requires that its contents are reduced to the minimum (ppb level). To this end there are applied chelating ions with the functional phosphonic and aminophosphonic groups. Also weakly basic anion exchangers in the free base form can be used for selective removal of lead(II) chloride complexes from the solutions of pH in the range 4-6. Also a combined process of cation exchange and precipitation is often applied for lead(II) removal form wastewaters (Pramanik et al. 2009). The average colle...

Comparative study of the application of chelating resins for rare earth recovery

“…Such resins exhibit a high affinity for the adsorption of heavy metal ions and proven performance in established hydrometallurgy applications. 9 However, the potential use of these resins in REE processing operations has not been widely explored. Early work on resins containing phosphonic acid functional groups revealed a high affinity for the adsorption of REE from acidic liquors.…”

Bioaccumulation of Trace Metals in Tissues of Rohu Fish for Environmental Risk Assessment

“…With respect to the human health, Al was recorded to be poisonous if it crossed the permissible limits causing various ailments such as Alzheimer's disease [44] [45]. Similarly cadmium accumulates in the human body by consuming plant-and animal-based foods, affecting several organs: liver, kidney, lung, bones, placenta, and central nervous system negatively [46]- [48] and reproductive development, hepatic, haematological and immunological damages [49] [50] and lead can pose a serious health risk to adult and children resulting in delayed physical and mental development and slight deficit and learning abilities [51].…”

“…Similarly cadmium accumulates in the human body by consuming plant-and animal-based foods, affecting several organs: liver, kidney, lung, bones, placenta, and central nervous system negatively [46]- [48] and reproductive development, hepatic, haematological and immunological damages [49] [50] and lead can pose a serious health risk to adult and children resulting in delayed physical and mental development and slight deficit and learning abilities [51]. Ingestion of high levels of copper salts is known to cause gastrointestinal upsets and zinc to damage many biochemical processes followed by its deposition in the kidneys, liver, gonads [45]. Iron is found in natural fresh and ground water, but have no health based guideline value, although high concentrations gave rise to consumer complaints due to its ability to discolour aerobic waters at concentrations above 0.3 mg/L [31].…”

Shallow Shell resin versus traditional resin: A case study for Cu(II) removal

“…Regeneration efficiency (RE, %) was calculated using Equation (14) and obtained results were summarized in Table 5.…”

“…Figure 5 also shows that the kinetic of resins are close to each other and only there is small difference at the beginning of the sorption. It should be noted that variations in the synthesis procedure which resulted in variations in the structure of the matrix, degree of cross linking, density of functional groups, proportion of functional groups and also the particle size affect the performance of resin [14].…”