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Carbon Filtering
Carbon filtering is a method of filtering that uses a bed of activated carbon to remove impurities from a fluid using adsorption. Mechanism Carbon filtering works by adsorption, in which pollutants in the fluid to be treated are trapped inside the pore structure of a carbon substrate. The substrate is made of many carbon granules, each of which is itself highly porous. As a result, the substrate has a large surface area within which contaminants can be trapped. Activated carbon is typically used in filters, as it has been treated to have a much higher surface area than non treated carbon. One gram of activated carbon has a surface area in excess of 3,000 m2 (32,000 sq ft). Common uses Carbon filtering is commonly used for water purification, air filtering and industrial gas processing, for example the removal of siloxanes and hydrogen sulfide from biogas. It is also used in a number of other applications, including respirator masks, the purification of sugarcane, some methods of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activated Carbon
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that increase the surface area available for adsorption (which is not the same as absorption) or chemical reactions. Activation is analogous to making popcorn from dried corn kernels: popcorn is light, fluffy, and has a surface area that is much larger than the kernels. ''Activated'' is sometimes replaced by ''active''. Due to its high degree of microporosity, one gram of activated carbon has a surface area in excess of as determined by gas adsorption. Charcoal, before activation, has a specific surface area in the range of . An activation level sufficient for useful application may be obtained solely from high surface area. Further chemical treatment often enhances adsorption properties. Activated carbon is usually derived from waste products such as coconut husks; waste f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decaffeination
Decaffeination is the removal of caffeine from coffee beans, cocoa, tea leaves, and other caffeine-containing materials. Decaffeinated drinks contain typically 1–2% of the original caffeine content, and sometimes as much as 20%. Decaffeinated products are commonly termed decaf. Decaffeination of coffee Friedlieb Ferdinand Runge performed the first isolation of pure caffeine from coffee beans in 1820, after the poet Goethe heard about his work on belladonna extract, and requested he perform an analysis on coffee beans. Though Runge was able to isolate the compound, he did not learn much about the chemistry of caffeine itself, nor did he seek to use the process commercially to produce decaffeinated coffee. Decaffeination processes Various methods can be used for decaffeination of coffee. These methods take place prior to roasting and may use organic solvents such as dichloromethane or ethyl acetate, supercritical CO2, or water to extract caffeine from the beans, while le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Technology
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use. Water is the most crucial compound for life on Earth, and having drinkable water is a key worldwide concern for the twenty-first century. All living things require clean, uncontaminated water as a basic requirement. Water covers more than 71 percent of the earth’s surface, but only around 1% of it is drinkable according to international standards due to various contaminations . Waste water discharge from industries, agricultural pollu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Waste-water Treatment Technologies
This page consists of a list of wastewater treatment technologies: See also *Agricultural wastewater treatment * Industrial wastewater treatment *List of solid waste treatment technologies * Waste treatment technologies *Water purification *Sewage sludge treatment Sewage sludge treatment describes the processes used to manage and dispose of sewage sludge produced during sewage treatment. Sludge treatment is focused on reducing sludge weight and volume to reduce transportation and disposal costs, and on red ... References * * Industrial Wastewater Treatment Technology DatabaseEPA. {{DEFAULTSORT:List Of Waste Water Treatment Technologies Chemical processes Environmental engineering *List Water pollution Water technology Waste-water treatment technologies Sanitation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Filter
A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation, accessible drinking water, public and private aquariums, and the safe use of ponds and swimming pools. Methods of filtration Filters use sieving, adsorption, ion exchanges, biofilms and other processes to remove unwanted substances from water. Unlike a sieve or screen, a filter can potentially remove particles much smaller than the holes through which its water passes, such as Nitrates or germs like ''Cryptosporidium.'' Among the methods of filtration, notable examples are sedimentation, used to separate hard and suspended solids from water and activated charcoal treatment, where the boiled water is poured through a piece of cloth to trap undesired residuals. Additionally, the use of machinery to work on desalinization and purificati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatile Organic Compound
Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility. VOCs are responsible for the odor of scents and perfumes as well as pollutants. VOCs play an important role in communication between animals and plants, e.g. attractants for pollinators, protection from predation, and even inter-plant interactions. Some VOCs are dangerous to human health or cause harm to the environment. Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Most VOCs are not acutely toxic, but may have long-term chronic health effects. Definitions Diverse definitions of the term VOC are in use. Canada Health Canada classifies VOCs as organic compounds that have boiling points roughly in the range of . The emphasis is placed on commonly encountere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EVAP
Vehicle emissions control is the study of reducing the emissions produced by motor vehicles, especially internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal c ...s. Types of emissions Emissions of many Air pollution, air pollutants have been shown to have Environmental health, variety of negative effects on public health and the natural environment. Emissions that are principal pollutants of concern include: *Hydrocarbons (HC) – A class of burned or partially burned fuel, hydrocarbons are toxins. Hydrocarbons are a major contributor to smog, which can be a major problem in urban areas. Prolonged exposure to hydrocarbons contributes to asthma, liver disease, lung disease, and cancer. Regulations governing hydrocarbons vary according to type of engine and jurisdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cigarette Filter
A cigarette filter, also known as a filter tip, is a component of a cigarette, along with cigarette paper, capsules and adhesives. Filters were introduced in the early 1950s. Filters may be made from plastic cellulose acetate fiber, paper or activated charcoal (either as a cavity filter or embedded into the plastic cellulose acetate fibers). Macroporous phenol-formaldehyde resins and asbestos have also been used. The plastic cellulose acetate filter and paper modify the particulate smoke phase by particle retention ( filtration), and finely divided carbon modifies the gaseous phase (adsorption). Filters are intended to reduce the harm caused by smoking by reducing harmful elements inhaled by smokers. They have been shown to reduce the risk of lung cancer. While laboratory tests show a reduction of "tar" and nicotine smoke, filters are ineffective at removing gases of low molecular weight, such as carbon monoxide. Most of these measured reductions occur only when the cigare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugarcane
Sugarcane or sugar cane is a species of (often hybrid) tall, perennial grass (in the genus '' Saccharum'', tribe Andropogoneae) that is used for sugar production. The plants are 2–6 m (6–20 ft) tall with stout, jointed, fibrous stalks that are rich in sucrose, which accumulates in the stalk internodes. Sugarcanes belong to the grass family, Poaceae, an economically important flowering plant family that includes maize, wheat, rice, and sorghum, and many forage crops. It is native to the warm temperate and tropical regions of India, Southeast Asia, and New Guinea. The plant is also grown for biofuel production, especially in Brazil, as the canes can be used directly to produce ethyl alcohol (ethanol). Grown in tropical and subtropical regions, sugarcane is the world's largest crop by production quantity, totaling 1.9 billion tonnes in 2020, with Brazil accounting for 40% of the world total. Sugarcane accounts for 79% of sugar produced globally (most of the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a fluid (the ''absorbate'') is dissolved by or permeates a liquid or solid (the ''absorbent''). Adsorption is a '' surface phenomenon'', while absorption involves the whole volume of the material, although adsorption does often precede absorption. The term '' sorption'' encompasses both processes, while '' desorption'' is the reverse of it. Like surface tension, adsorption is a consequence of surface energy. In a bulk material, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are fulfilled by other atoms in the material. However, atoms on the surface of the adsorbent are not wholly surrounded by other adsorbent atoms and therefore can attract adsorbates. The exact nature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogas
Biogas is a mixture of gases, primarily consisting of methane, carbon dioxide and hydrogen sulphide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste and food waste. It is a renewable energy source. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogen inside an anaerobic digester, biodigester or a bioreactor. Biogas is primarily methane () and carbon dioxide () and may have small amounts of hydrogen sulfide (), moisture and siloxanes. The gases methane, hydrogen, and carbon monoxide () can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat. Biogas can be compressed after removal of carbon dioxide and hydrogen sulphide, the same way as natural gas is compressed to CNG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is ''stinkdamp''. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or it or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
