Lead in surface water

Group : LEAD IN SURFACE WATER Name: LE HONG MINH NGUYEN TA NAM NGUYEN VIET HA HA CONG DUC NGUYEN DANH LAN An Overview Lead has been identified in at least 1,272 of the 1,684 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2006) However, the number of sites evaluated for lead is not known Lead is dispersed throughout the environment primarily as the result of anthropogenic activities In the air, lead is in the form of particles and is removed by rain or gravitational settling The solubility of lead compounds in water is a function of pH, hardness, salinity, and the presence of humic material Solubility is highest in soft, acidic water The sink for lead is the soil and sediment Because it is strongly adsorbed to soil, it generally is retained in the upper layers of soil and does not leach appreciably into the subsoil and groundwater Lead compounds may be transformed in the environment to other lead compounds; however, lead is an element and cannot be destroyed Anthropogenic sources of lead include the mining and smelting of ore, manufacture of lead-containing products, combustion of coal and oil, and waste incineration Many anthropogenic sources of lead, most notably leaded gasoline, leadbased paint, lead solder in food cans, lead-arsenate pesticides, and shot and sinkers, have been eliminated or strictly regulated due to lead’s persistence and toxicity Because lead does not degrade, these former uses leave their legacy as higher concentrations of lead in the environment Plants and animals may bioconcentrate lead, but lead is not biomagnified in the aquatic or terrestrial food chain Why we study about lead pollution? The general population may be exposed to lead in ambient air, foods, drinking water, soil, and dust Segments of the general population at highest risk of health effects from lead exposure are preschool-age children and pregnant women and their fetuses Within these groups, relationships have been established between lead exposure and adverse health effects Other segments of the general population at high risk include individuals living near sites where lead was produced or disposed Potential for human exposures Human exposure to lead above baseline levels is common Baseline refers to the naturally-occurring level of lead in soil or dust that is not due to the influence of humans Some of the more important leadexposures have occurred as a result of living in urban environments, particularly in areas near stationary emission sources (e.g., smelters); consumption of produce from family gardens; renovation of homes containing lead-based paint; pica (an abnormal eating habit in children); contact with interior lead paint dust; occupational exposure; secondary occupational exposure (e.g., families of workers using lead); smoking; and wine consumption Higher than normal exposures may also occur to residents living in close proximity to NPL sites that contain elevated levels of lead The highest and most prolonged lead exposures are found among workers in the lead smelting, refining, and manufacturing industries Source release to environment While lead is a naturally-occurring chemical, it is rarely found in its elemental form It occurs in the Earth’s crust primarily as the mineral galena (PbS), and to a lesser extent as anglesite (PbSO4) and cerussite (PbCO3) Lead minerals are found in association with zinc, copper, and iron sulfides as well as gold, silver, bismuth, and antimony minerals It also occurs as a trace element in coal, oil, and wood Lead released from natural sources, such as volcanoes, windblown dust, and erosion, are minor compared with anthropogenic sources Industrial sources of lead can result from the mining and smelting of lead ores, as well as other ores in which lead is a by-product or contaminant In these processes, lead may be released to land, water, and air Electrical utilities emit lead in flue gas from the burning of fuels, such as coal, in which lead is a contaminant Because of the large quantities of fuel burned by these facilities, large amounts of lead can be released I Sources of lead Lead appear in surface water almost caused of human activities, from building, produce processes Lead waterworks were often applied in some previous decades, and these may still be present in old buildings Lead from pipes may partially dissolve in the water flowing through Lead may bind to carbonate, therefore lower amounts of lead dissolve in hard water Inside the pipes, a layer of hardly soluble alkalic lead carbonate is formed This layer functions as a protective coating for the underlying lead of the pipes Despite its toxicity, lead (II) acetate was applied from the 19th century until now, to sweeten wine and other beverages and food stuffs The lead compounds are collected and store in surface water in many years Mining industry is also the source that increase the concentration of lead compounds in surface water.Water pollution containing lead compounds derived from lead ores in the mining industry was first mentioned by architect Vitruvius, in 20 B.C., when he gave out a warning of its health effects In Rome lead was often released as a by- product of silver mining Lead white, an alkalic lead carbonate (2PbCO3.Pb(OH)2), is a white pigment It is no longer applied because of its extreme toxicity Selling tubes of lead white is now prohibited in the European Union Organic lead is applied in petroleum production, and inorganic lead compounds are applied for battery and paint production Most industrially processed lead is applied for fabricating computer and TV screens The lead compound tetra-ethyl lead is applied as an additive in fuels This organic lead compounds is quickly converted to inorganic lead, and ends up in water, sometimes even in drinking water Fortunately, this form of release of lead is less and less abundant In architecture lead is applied in roofs and in stained glass windows Generally, lead dissolved or suspended in wastewater mostly stems from streets, pipes and soils In The Netherlands, lead in food causes about half of the human lead exposure Lead was also used in paint to add color, improve the ability of the paint to hide the surface it covers, and to make it last longer In 1978 the federal government banned lead paint for use in homes Homes built before 1978 probably contain lead-based paint Painted toys and furniture made before 1978 may also contain lead-based paint Lead-based paint becomes a concern when it chips, turns into dust, or gets into the soil All sources above release lead and lead compounds and it will distribute in also surface and ground water II Fate of lead Physical properties: Lead is a heavy, soft, gray solid It is both ductile and malleable Ductile means capable of being drawn into thin wires Malleable means capable of being hammered into thin sheets It has a shiny surface when first cut, but it slowly tarnishes (rusts) and becomes dull Lead is easily worked "Working" a metal means bending, cutting, shaping, pulling, and otherwise changing the shape of the metal o Phase : Solid - Color: Bluish-White - Luster: A shine or glow - Malleability: Capable of being shaped or bent - Conductivity: Poor transmission of heat or electricity - Relatively soft - Tensile: It can be stretched without breaking - Density: 11.34 g.cm-3 at 20°C - Melting point: 327 °C - Boiling point:1755 °C Chemical properties chemical symbol: Pb (originates from the word “plumbum” which is the latin name for lead) o Reactivity with water: The surface of metallic lead is protected by a thin layer of lead oxide, PbO It does not react with water under normal conditions o Oxidation: Does not readily react with oxygen in the air at normal condition Only upon heating lead to 600-800°C does lead react with oxygen in air to from lead oxide, PbO o o 2Pb(s) + O2(g) → 2PbO(s) Flammability: Does not burn Reaction of lead with the halogens: Lead metal reacts vigorously with fluorine, F2, at room temperature and chlorine, Cl2, on warming to form the poisonous dihalides lead(II) fluoride, PbF2, and lead(II) chloride, PbCl2, respectively Pb(s) + F2(g) → PbF2(s) Pb(s) + Cl2(g) → PbCl2(s) o Reactivity with acids: The surface of metallic lead is protected by a thin layer of lead oxide, PbO This renders the lead essentially insoluble in sulphuric acid, and so, in the past, a useful container of this acid Lead reacts slowly with hydrochloric acid and nitric acid, HNO3 In the latter case, nitrogen oxides are formed together with lead(II) nitrate, Pb(NO3)2.Corrosion: Very resistant to corrosion but tarnishes upon exposure to air o Reaction of lead with bases: Lead dissolves slowly in cold alkalis to form plumbites o Toxicity: Toxic Common oxidation states: +2, +4 (+2 is most common) Chemical properties of Pb2+ o With CL In solution have ion clorua, Pb2+ react with Cl- form precipitant Pb2+(aq) + 2Cl-(aq) PbCl2(s) (Slow precipitation rate) When Cl- excess, precipitant dissolve because of forming complex ion tetrachloroplumbate(II) PbCl2(s) + 2CL-(aq) [PbCl4]2-(aq) o With Sulfate Lead ion create precipitation with sulfate ion Pb2+(aq) + SO42-(aq) PbSO4(s) PbSO4 solute in base or acetate salt PbSO4 + 4OH- [Pb(OH)4]2-(aq) + SO2-(aq) PbSO4 + 2CH3COO-(aq) Pb(CH3COO)2-(aq) + SO42-(aq) o With ammonia solution Ion Pb2+ react with ammonia solution form single salt precipitation (ex: Pb2O(NO3)2 ) appear more than Pb(OH)2: Pb2+(aq) + 2NH3(aq) + 3H2O(l) + 2NO3-(aq) Pb2O(NO3)2(s) + H2O(l) + 2NH4+(aq) Precipitant does not solute when NH3 excess o With strong base When react with strong base solution,Pb2+ form black precipitation Precipitant solute when base excess Pb2+(aq) + OH-(aq) Pb(OH)2(s) Pb(OH)2(s) + 2OH-(aq) [Pb(OH)4)]2- o Biologic Fate of Lead Biologic fate of lead once it enters the human body depends on a variety of factors including nutritional status, health, and age + Adults typically absorb up to 20% of ingested lead + Most inhaled lead in the lower respiratory tract is absorbed + Most of the lead that enters the body is excreted in urine or through biliary clearance o Lead in the Blood + The half-life of lead in adult human blood has been estimated to be from 28-36 days + Approximately 99% of the lead in blood is associated with red blood cells +Blood lead (BLL) is also important because the BLL is the most widely used measure of lead exposure o Lead in Mineralizing Tissues (Bones and Teeth) The bones and teeth of adults contain about 94% of their total lead body burden; in children, the figure is approximately 73% Two physiological compartments appear to exist for lead in cortical and trabecular bone + The inert component stores lead for decades Under certain circumstances, this apparently inert lead will leave the bones and reenter the blood and soft tissue organs + The labile component readily exchanges bone lead with the blood III lead process in surface water Lead is one of the heavy metals greatly affect the environment pollution because it is capable of long-term accumulation in the body and cause toxicity to humans, aquatic animals through the food chain Redox reactions of lead in the environment as follows: Pb+2 + 2H2O «» PbO2 + 4H+ 2eLead Pb2 + is relatively stable, strong affinity Therefor, it can replace other metals in the structure of the enzyme Most inorganic salts of lead Pb2 + (PBS, PbCO3, PbSO4,) is less soluble substances, so lead content in groundwater is relatively low They can create hydrogen, carbonate, sulfate and carboxyl complexes in the atmosphere Lead hydoxide is amphoteric hydroxide, so solubility can be increased with increasing pH and increasing concentrations of CO2 in the liquid phase: Pb(OH)2 + OH- «» Pb(OH)3- In the hydrosphere, existing compounds Pb2 + is hydrated, the soluble reaction, lead compounds in suspended form Lead content of natural water or water feeding for living activity is determined by a number of factors such as: - The formation of complexes with inorganic ligands or organic sector; - The dissolution or precipitation of lead compounds; - Adsorption of lead compounds on colloidal dust particles, or organic colloidal particles; - The transformation of living organisms; - The flocculation or coagulation For example, the standard of the World Health Organization for the maximum permitted concentration of lead in drinking water was 0:05 mg / liter, coastal water, the lake is 0.1 mg / liter Groundwater contains less lead (0.01 mg / liter), seawater contains 0.03 micrograms/ liter In the water flowing through the pipelines, we can observe that lead level can up to 100 micrograms/ liter Lead compounds in water-soluble form or suspended in the water will flow into the sea A significant portion of lead compounds go to the living organisms in the food chain or be retained in the sediment Fresh water is mainly in the form of lead carbonate complexes, sea water contain lead compounds mainly in the form of chloride complexes, while in water of land, lead in the complex shape of humic or fulvic acid IV Environmental issues People, animals, and fish are mainly exposed to lead by breathing and ingesting it in food, water, soil, or dust Lead accumulates in the blood, bones, muscles, and fat Infants and young children are especially sensitive to even low levels of lead • Damages organs - Lead causes damage to the kidneys, liver, brain and nerves, and other organs Exposure to lead may also lead to osteoporosis (brittle bone disease) and reproductive disorders • Affects the brain and nerves - Excessive exposure to lead causes seizures, mental retardation, behavioral disorders, memory problems, and mood changes Low levels of lead damage the brain and nerves in fetuses and young children, resulting in learning deficits and lowered IQ • Affects the heart and blood - Lead exposure causes high blood pressure and increases heart disease, especially in men Lead exposure may also lead to anemia, or weak blood • Affects animals and plants - Wild and domestic animals can ingest lead while grazing They experience the same kind of effects as people who are exposed to lead Low concentrations of lead can slow down vegetation growth near industrial facilities • Affects fish - Lead can enter water systems through runoff and from sewage and industrial waste streams Elevated levels of lead in the water can cause reproductive damage in some aquatic life and cause blood and neurological changes in fish and other animals that live there What are the environmental effects of lead in water? Lead and lead compounds are generally toxic pollutants Lead(II)salts and organic lead compounds are most harmful ecotoxicologically Lead salts are attributed to water hazard class 2, and consequently are harmful The same applies to lead compounds such as lead acetate, lead oxide, lead nitrate, and lead carbonate Lead limits plant chlorophyll synthesis Nevertheless, plants can take up high levels of lead up to 500 ppm from soils Higher concentrations negatively influence plant growth Through plant uptake, lead enters food chains Consequently, lead pesticide application is prohibited in most countries Lead accumulates in organisms, sediments and sludge Lead in wastewater mostly stems from streets and roofs Lead exists as four stable isotopes, and no less than 26 instable isotopes What are the health effects of lead in water? The human body contains approximately 120 mg of lead About 10-20% of lead is absorbed by the intestines Symptoms over overexposure to lead include colics, skin pigmentation and paralysis Generally, effects of lead poisoning are neurological or teratogenic Organic lead causes necrosis of neurons Inorganic lead causes axonal degeneration and demyelination Both species of lead may cause cerebral oedema and congestion Organic lead compounds are absorbed quicker, and therefore pose a greater risk Organic lead derivates may be carcinogenic Women are generally more susceptible to lead poisoning than men Lead causes menstrual disorder, infertility and spontaneous abortion, and it increases the risk of stillbirth Foetuses are more susceptible to lead poisoning than mothers, and generally foetuses even protect mothers from lead poisoning A long time ago lead was applied as a measure of birth control, for example as a spermicidal, and to induce abortion Children may absorb a larger amount of lead per unit body weight than adults (up to 40%) Consequently, children are generally more susceptible for lead poisoning than adults Symptoms include lower IQs, behavioural changes and concentration disorder Lead accumulates in leg tissue The most severe type of lead poisoning causes encephalopathy Lead toxicity is induced by lead ions reacting with free sulfydryl groups of proteins, such as enzymes These are deactivated Furthermore, lead may interact with other metal ions V References Hóa học môi trường, Đặng Kim Chi, Nxb Khoa học kĩ thuật Nghiên cứu khảnăng tách loại Pb2+trong nước nano sắt kim loại, Nguyễn Thị Nhung*, Nguyễn ThịKim Thường, Tạp chí Khoa học ĐHQGHN, Khoa học Tự nhiên Công nghệ 24 (2008) 305-30 3 Lead-210 and polonium-210 in the surface water of the Pacific, SHIZUO TSUNOGAI and YOSHIYUKI NOZAKI, Geochemical Journal, Vol 5, pp 165 to 173, 1971 Effects of blending of desalinated water with treated surface drinking water on copper and lead release, Haizhou Liu, Kenneth D Schonberger, Gregory V Korshin, John F Ferguson, Paul Meyerhofer, Erik Desormeaux, Heidi Luckenbach, Water Research, Volume 44, Issue 14, July 2010, Pages 4057-4066 Water contamination: Impact of tin-lead solder, K.S Subramanian, V.S Sastri, M Elboujdaini, J.W Connor, A.B.C Davey, Water Research, Volume 29, Issue 8, August 1995, Pages 18271836 Lead speciation in surface waters of the eastern North Pacific, Gabriele Capodaglio, Kenneth H Coale, Kenneth W Bruland, Marine Chemistry, Volume 29, 1990, Pages 221-233 [...]... Consequently, lead pesticide application is prohibited in most countries Lead accumulates in organisms, sediments and sludge Lead in wastewater mostly stems from streets and roofs Lead exists as four stable isotopes, and no less than 26 instable isotopes What are the health effects of lead in water? The human body contains approximately 120 mg of lead About 10-20% of lead is absorbed by the intestines Symptoms... blending of desalinated water with treated surface drinking water on copper and lead release, Haizhou Liu, Kenneth D Schonberger, Gregory V Korshin, John F Ferguson, Paul Meyerhofer, Erik Desormeaux, Heidi Luckenbach, Water Research, Volume 44, Issue 14, July 2010, Pages 4057-4066 5 Water contamination: Impact of tin -lead solder, K.S Subramanian, V.S Sastri, M Elboujdaini, J.W Connor, A.B.C Davey, Water. .. fish - Lead can enter water systems through runoff and from sewage and industrial waste streams Elevated levels of lead in the water can cause reproductive damage in some aquatic life and cause blood and neurological changes in fish and other animals that live there What are the environmental effects of lead in water? Lead and lead compounds are generally toxic pollutants Lead( II)salts and organic lead. .. amount of lead per unit body weight than adults (up to 40%) Consequently, children are generally more susceptible for lead poisoning than adults Symptoms include lower IQs, behavioural changes and concentration disorder Lead accumulates in leg tissue The most severe type of lead poisoning causes encephalopathy Lead toxicity is induced by lead ions reacting with free sulfydryl groups of proteins, such... to lead include colics, skin pigmentation and paralysis Generally, effects of lead poisoning are neurological or teratogenic Organic lead causes necrosis of neurons Inorganic lead causes axonal degeneration and demyelination Both species of lead may cause cerebral oedema and congestion Organic lead compounds are absorbed quicker, and therefore pose a greater risk Organic lead derivates may be carcinogenic... heart and blood - Lead exposure causes high blood pressure and increases heart disease, especially in men Lead exposure may also lead to anemia, or weak blood • Affects animals and plants - Wild and domestic animals can ingest lead while grazing They experience the same kind of effects as people who are exposed to lead Low concentrations of lead can slow down vegetation growth near industrial facilities... ecotoxicologically Lead salts are attributed to water hazard class 2, and consequently are harmful The same applies to lead compounds such as lead acetate, lead oxide, lead nitrate, and lead carbonate Lead limits plant chlorophyll synthesis Nevertheless, plants can take up high levels of lead up to 500 ppm from soils Higher concentrations negatively influence plant growth Through plant uptake, lead enters food chains... more susceptible to lead poisoning than men Lead causes menstrual disorder, infertility and spontaneous abortion, and it increases the risk of stillbirth Foetuses are more susceptible to lead poisoning than mothers, and generally foetuses even protect mothers from lead poisoning A long time ago lead was applied as a measure of birth control, for example as a spermicidal, and to induce abortion Children... are deactivated Furthermore, lead may interact with other metal ions V References 1 Hóa học môi trường, Đặng Kim Chi, Nxb Khoa học và kĩ thuật 2 Nghiên cứu khảnăng tách loại Pb2+trong nước bằng nano sắt kim loại, Nguyễn Thị Nhung*, Nguyễn ThịKim Thường, Tạp chí Khoa học ĐHQGHN, Khoa học Tự nhiên và Công nghệ 24 (2008) 305-30 3 Lead- 210 and polonium-210 in the surface water of the Pacific, SHIZUO TSUNOGAI... solder, K.S Subramanian, V.S Sastri, M Elboujdaini, J.W Connor, A.B.C Davey, Water Research, Volume 29, Issue 8, August 1995, Pages 18271836 6 Lead speciation in surface waters of the eastern North Pacific, Gabriele Capodaglio, Kenneth H Coale, Kenneth W Bruland, Marine Chemistry, Volume 29, 1990, Pages 221-233