Heavy Metals Concentration Of Stream Sediment: Fill & Download for Free

Some of the technical duties of a chemist in the Geological survey of India are mentioned below.Determination of major, minor, trace and ultra-trace elements by wet Chemical and instrumental analysis of: a) Rock, minerals, ores for geochemical reconnaissance projects as well for mineral investigation. b) Water samples, physicochemical analysis including trace elements for environmental and urban geological studies. c) Stream sediments, Regolith, Humus, soil samplesTo provide chemical data for preparation of regional geo-chemical map and data-base to study the behaviour ,concentration and dispersion pattern of various elements in the area.To generate base line geochemical data for multipurpose uses like developing natural resources and applications in environmental, agricultural, human health and other societal concerns.Isotopic characterization of major Indian Coalfields and their potential as heavy metal pollutantsCharacterization of pattern, extent and source of bio-accumulation of heavy metals in different food items, cosmetics and in human teeth (and other organs, if feasible).Visit to field sites along with a team of geologist to collect specific samples required for a project.

Ocean pollutants are many and varied. A percentage of just about everything we throw away or put on our yards/croplands ends up in the ocean. This causes all sorts of issues, some obvious, some insidiously hidden below the surface, some long term, some fleeting. Here's a very incomplete list:Plastic: Some floats, some sinks, some degrades into small particles, some remains fairly intact over 100's-1000's of years. Individuals from just about every marine animal species have been found to have consumed some amount of plastic. (see also: Great Pacific garbage patch, 10 Ways to Reduce Plastic Pollution, Plastic Oceans)Fertilizer: Fertilizers used on croplands, lawns and gardens run off into our rivers and streams and eventually reach the ocean. Large concentrations of nutrients and chemicals from human-applied fertilizers cause large blooms of algae, which in turn feed bacteria near the ocean bottom. These bacteria use up ALL of the oxygen in the water, killing fish and other animals. Huge dead zones result. (The annual dead zone off the mouth of the Mississippi river is larger than the state of New Jersey). Dead zones cost our fishing industries 100's of millions of dollars every year, at minimum. (see: http://www.scientificamerican.com/article/oceanic-dead-zones-spread/, Ocean Dead Zones: Reducing Nitrogen Runoff Could Restore Vital Oxygen)Fishing Gear: Fishing lines, trawl nets, weights, hooks, etc all end up in the ocean. Trawl nets in particular can be incredibly destructive, scraping across reefs, entangling marine mammals and turtles, and fouling active lines and nets from active fishing vessels. Every few months, a whale or shark is in the news with humans attempting to free it from some kind of fishing line or net. Imagine how many more smaller or less-watched creatures are killed each year in similar circumstances.Heavy metals: Industrial activities and burning of fossil fuels, particularly coal, release toxic metals (mercury, lead, etc) into the worlds water systems. Even if we didn't care about the health of fish, whales, sharks, etc, this would still be a problem because we eat fish. Large fish, such as Tuna, eat smaller fish, concentrating heavy metals. That's why pregnant women need to watch their fish intake now, when it wasn't a problem 500 years ago. (see: Mercury in fish, The best seafood selections to avoid heavy metals)Oil spills: Seemingly obvious, but more extensive and long-lasting than most people realize. Large oil spills, such as the Deepwater Horizon oil spill in 2010 make news, but countless smaller spills and leaks occur every year. In some areas, such as the Gulf of Mexico, native microorganisms eat the hydrocarbons in the water, speeding recovery in the ecosystem after a spill. In other areas, such as Prince William Sound (Exxon Valdez oil spill), the water is too cold for these organisms, and the oil remains in the water, sediments and ecosystem for many decades. (see: Oil spill-wikipedia)More information:Marine pollution (wikipedia)Ocean Trash Plaguing Our Sea

Carbon dioxide (CO2) is a slightly toxic, odorless, colorless gas with a slightly pungent, acid taste. Carbon dioxide is a small but important constituent of air.It is a necessary raw material for most plant life, which remove carbon dioxide from air using the process of photosynthesis.A typical concentration of CO2- in air is currently about 0.040% or 404 ppm. The concentration of atmospheric carbon dioxide rises and falls in a seasonal pattern over a range of about 6 ppmv. The concentration of CO2 in air has also been steadily increasing from year to year for over 70 years. The current rate of increase is about 2.5 ppm per year.Carbon dioxide is formed by combustion and by biological processes. These include decomposition of organic material, fermentation and digestion. As an example, exhaled air contains as much as 4% carbon dioxide, or about 100 times the amount of carbon dioxide which was breathed in.Large quantities of CO2are produced by lime kilns, which burn limestone (primarily calcium carbonate) to produce calcium oxide ( lime, used to make cement); and in the production of magnesium from dolomite (calcium magnesium carbonate). Other industrial activities which produce large amounts of carbon dioxide are ammonia production and hydrogen production from natural gas or other hydrocarbon raw materials.The concentration of CO2 - in air and in stack gases from simple combustion sources (heaters, boilers, furnaces) is not high enough to make carbon dioxide recovery commercially feasible. Producing carbon dioxide as a commercial product requires that it be recovered and purified from a relatively high-volume, CO2-rich gas stream, generally a stream which is created as an unavoidable byproduct of a large-scale chemical production process or some form of biological process.In almost all cases, carbon dioxide which is captured and purified for commercial applications would be vented to the atmosphere at the production point if it was not recovered for transport and beneficial use at other locations.The most common operations from which commercially-produced carbon dioxide is recovered are industrial plants which produce hydrogen or ammonia from natural gas, coal, or other hydrocarbon feedstock, and large-volume fermentation operations in which plant products are made into ethanol for human consumption, automotive fuel, or industrial use. Breweries producing beer from various grain products are a traditional source. Corn-to-ethanol plants have been the most rapidly growing source of feed gas for CO2 recovery. CO2-rich natural gas reservoirs found in underground formations found primarily in the western United States and in Canada are another source of recoverable carbon dioxide.CO2- from both natural and industrial sources is used to enhance production of oil from older wells by injecting the carbon dioxide into appropriate underground formations. Carbon dioxide is used selectively, primarily in wells which will benefit not only from re-pressurization, but also from a reduction in viscosity of the oil in the reservoir caused by a portion of the CO2- dissolving in the oil. (The extent to which carbon dioxide will dissolve in the oil varies with the type of petroleum present in the reservoir. If the viscosity reduction effect will be minimal, nitrogen, which is usually less expensive, may be used as the pressurant instead.)Carbon dioxide will not burn or support combustion. Air with a carbon dioxide content of more than 10% will extinguish an open flame, and, if breathed, can be life-threatening. Such concentrations may build up in silos, digestion chambers, wells, sewers and the like. Caution must be exercised when entering these types of confined spaces.CO2- gas is 1.5 times as heavy as air, thus if released to the air it will concentrate at low elevations. Carbon dioxide will form "dry ice" at -78.5ºC (-109.3º F). One kg of dry ice has the cooling capacity of 2 kg of ordinary ice. Gaseous or liquid carbon dioxide, stored under pressure, will form dry ice through an auto-refrigeration process if rapidly depressured.Carbon dioxide is commercially available as high pressure cylinder gas, relatively low pressure (about 300 psig or 20 barg) refrigerated liquid, or as dry ice.Large quantities are produced and consumed at industrial sites making fertilizers, plastics and rubber.Carbon dioxide is a versatile material, being used in many processes and applications - each of which takes advantage of one or more these characteristics: reactivity, inertness and/ or coldness.Carbon dioxide is commonly used as a raw material for production of various chemicals; as a working material in fire extinguishing systems; for carbonation of soft drinks; for freezing of food products such as poultry, meats, vegetables and fruit; for chilling of meats prior to grinding; for refrigeration and maintenance of ideal atmospheric conditions during transportation of food products to market; for enhancement of oil recovery from oil wells; and for treatment of alkaline water.Carbon dioxide in air is considered to be a greenhouse gas because of its ability to absorb infrared light.The concentration of CO2 - in the Earth's atmosphere has been increasing at a noticeable rate for much of the past century, There is much interest and concern over the inter-relationship between the levels of carbon dioxide in air and the subject of global warming,Carbon dioxide plays a major role as a component of the carbon cycle in which carbon is exchanged between the atmosphere, the terrestrial biosphere (which includes freshwater systems and soil), the oceans, and sediments (including fossil fuels). These interactions are complex and widespread. They undoubtedly can be, and are, influenced by many types of human activities, but the extent to which humans have impacted these processes, and will impact them in the future, remains the subject of much research and debate.Multi-Industry Uses for Carbon Dioxide (CO2):Carbon dioxide in solid and in liquid form is used for refrigeration and cooling. It is used as an inert gas in chemical processes, in the storage of carbon powder and in fire extinguishers.Metals Industry:Carbon dioxide is used in the manufacture of casting molds to enhance their hardness.Manufacturing and Construction Uses:Carbon dioxide is used on a large scale as a shield gas in MIG/MAG welding, where the gas protects the weld puddle against oxidation by the surrounding air. A mixture of argon and carbon dioxide is commonly used today to achieve a higher welding rate and reduce the need for post weld treatment.Dry ice pellets are used to replace sandblasting when removing paint from surfaces. It aids in reducing the cost of disposal and cleanup.Chemicals, Pharmaceuticals and Petroleum Industry Uses:Large quantities are used as a raw material in the chemical process industry, especially for methanol and urea production.Carbon dioxide is used in oil wells for oil extraction and to maintain pressure within a formation.. When CO2- is pumped into an oil well, it is partially dissolved into the oil, rendering it less viscous, allowing the oil to be extracted more easily from the bedrock. Considerably more oil can be extracted from through this process.Rubber and Plastics Industry Uses:Flash is removed from rubber objects by tumbling them with crushed dry ice in a rotating drum.Food and Beverages Uses for Carbon Dioxide:Liquid or solid carbon dioxide is used for quick freezing, surface freezing, chilling and refrigeration in the transport of foods.In cryogenic tunnel and spiral freezers, high pressure liquid CO2 is injected through nozzles that convert it to a mixture of CO2 - gas and dry ice "snow" that covers the surface of the food product. As it sublimates (goes directly from solid to gas states) refrigeration is transferred to the product.Carbon dioxide gas is used to carbonate soft drinks, beers and wine and to prevent fungal and bacterial growth.Liquid carbon dioxide is a good solvent for many organic compounds. It is used to de-caffeinate coffee.It is used as an inert “blanket”, as a product-dispensing propellant and an extraction agent. It can also be used to displace air during canning.Supercritical CO2- extraction coupled with a fractional separation technique is used by producers of flavors and fragrances to separate and purify volatile flavor and fragrances concentrates.Cold sterilization can be carried out with a mixture of 90% carbon dioxide and 10% ethylene oxide, the carbon dioxide has a stabilizing effect on the ethylene oxide and reduces the risk of explosion.Health Care Uses:Carbon dioxide is used as an additive to oxygen for medical use as a respiration stimulant.Environmental Uses:Used as a propellant in aerosol cans, it replaces more environmentally troublesome alternatives.By using dry ice pellets to replace sandblasting when removing paint from surfaces, problems of residue disposal are greatly reduced.It is used to neutralize alkaline water.Miscellaneous Uses for Carbon Dioxide (CO2):Liquid carbon dioxide's solvent potential has been employed in some dry cleaning equipment as a substitute for conventional solvents. This use is still experimental - some types of soil are more effectively removed with traditional dry cleaning equipment, and the equipment is more expensive.Yields of plant products grown in greenhouses can increase by 20% by enriching the air inside the greenhouse with carbon dioxide. The target level for enrichment is typically a carbon dioxide concentration of 1000 PPM (parts per million) - or about two and a half times the level present in the atmosphere.