Introduction “AOX” is the abbreviation of the sum parameter for water soluble “adsorbable organic halogens” in which ‘A’ stands for adsorbable, ‘O’ for organic and ‘X’ for the halogens chlorine, bromine and iodine. After the introduction of the AOX in 1976, this parameter has been correctly used for “real” AOX constituents (DDT and its metabolites, PCBs, etc.); but also misused for non-adsorbable adsorbed OX-compounds, mostly high molecular organohalogens in plants and even to inorganic compounds being neither organic nor adsorbable. The question of natural “Adsorbable Organic Halogens” (AOX) formed by living organisms and/or during natural abiogenic processes has been definitively solved by the known existence of already more than 3650 organohalogen compounds, amongst them the highly reactive, cancerogenic vinyl chloride (VC). In 1996, the European Committee for Standardization accepted the “Determination of adsorbable organically bound halogens (AOX)” as European Standard. 2. Physicochemical constants of major AOX compounds in Paper Mill Industry 2.1. Chloromethanols The typical Chloromethanols appear in paper milling industry is dichloromethane and trichloromethane. 2.2. X-phenol compounds: 2.3. X-benzene compounds: 2.4. X-dibenzodioxin compounds: 2.5. Dibenzofurans: 3. Virulence of some major AOX compounds Most of the AOX compounds have toxic effects. These compounds can accumulate in the animal/human fat tissue and lead to cancer, multiple animal/human organs damage and embryonic deformity. Research shows that different AOX compound will case different effects. The different toxic effects from different AOX compounds are shown in Table 3.1. Ta... ... middle of paper ... ...xidize and become less toxic. Usually, this method is combine with ozonation process. Membrane filtration is a filtration technique can well performance in remove color, AOX and COD from paper mill wastewater. Researchers find out that if membrane filtration combine with dissolved air flotation can result a much higher percentage removal of TOC, color and suspended solid. Also, membrane filtration is good for heavy metal removal. Ozonation is very useful in pulp wastewater treatment. This process can convert COD to BOD. Many chemical compounds are sensitive to ozonation process. So this process can have a large impact in decrease the concentration of AOX in pulp wastewater and other colored/colorless chemical compounds. Biological Treatment Performance Works Cited Treatment of pulp and paper mill wastewater—a review
This last process is significant not only because it brought dioxin the current notoriety but it also is a chemical process used to make products that were used and are still been used in many applications. These applications include pesticide, herbicide, defoliating agent such as Agent Orange, cleaning agent and electrical insulation. Consequently, human exposure to dioxin is not a recent phenomenon and the dangers of dioxin are not unknown. Only in recent years, especially after the Vietnam War, has the media concentrated on the dangers and impact of dioxin.
Orange and Cancer"). The chemical was sprayed from airplanes on trees, base perimeters, roadways, and communication lines. It was also sprayed by riverboats and trucks (committee, 74). Agent Orange is a dioxin herbicide containing Dichlorophenoxyacetic and Trichlorophenoxyacetic acids. "Dioxin is the most toxic and most durable chemical mankind has developed so far" ("Vietnamese"). Both acids are highly toxic and considered mutagens ("Toxipedia"). Trichlorophenoxyacetic is considerabl...
Schecter, Arnold, et al. "Recent Dioxin Contamination From Agent Orange in Residents of a Southern Vietnam City." FFRD. N.p., May 2011. . Rpt. in JOEM. Vol. 43. N.p.: n.p., n.d. N. pag. 5. FFRD. Web. 3 Apr. 2011.
The MSDS, or material safety data sheet, for 2-butoxyethanol outlines basic health risks that accompany it, along with basic chemical and physical properties. One of the physical properties is the fact that it is a liquid at room temperature, which means it takes the shape of its container and its molecules are not definitively packed. Chemical properties include flammability, which is whether or not it ignites easily, and toxicity, whether or not it is poisonous to humans. 2-butoxyethanol is both flammable and toxic, meaning it does ignite easily and is poisonous to humans It says that 2-butoxyethanol has a health hazard number of two and fire hazard number of two. The health hazard number means that it can cause injury upon exposure and requires rapid medical treatment. The fire hazard number means that it can ignite w...
Orange contains relatively high levels of an exceedingly poisonous contaminant known as Dioxin."(Arison, 1) Dioxin is what remains after the herbicides dissolve; this is not a harmful substance found in nature, but rather a man made poison. The introduction to using resources: Choices and Trade-off states that "The choices people have made in just the last hundred years are largely responsible for what we call the environmental crisis."(Walker, 276) We made this killer and now we are forced to live with it. The destruction this chemical caused to the vegetation should have been the first clue that what destroys nature will in due time destroy us. We are the cause for this mess but we should have been notified much earlier about the potential risk associated with Agent Orange.
U.S. Chemical Safety and Hazard Investigation Board. (March 20, 2007). Final Investigation Report. Retrieved July 26, 2010, from U.S. Chemical and Safety Board: http://www.csb.gov/assets/document/CSBFinalReportBP.pdf
Comment on class result with respect to differences in filter types, differences in filter assemblies, and overall on the confidence you would have in using this type of sterilisation process in preparation of pharmaceutical products. List the factors that may cause contamination during filtration. (20 marks)
Acrylamide or propenic acid amide (AcA) has also been called a cooking carcinogen.AcA has been widely used for decades in various spheres of life, mostly (99.9%) for manufacturing of polyacrylamide (PAA). Acrylamide (CH_2 = CH-CONH_2) has been an important industrial chemical in particular it has been used worldwide to synthesize polyacrylamide. Polyacrylamide has been used for various purposes, including removal of suspended solids from industrial waste water, soil conditioner, grouting agents, surfactant for herbicide mixtures, a stationary phase for laboratory separations, and cosmetic formulations. Consequently, since acrylamide is formed from polyacrylamide degradation, it has been known to be present in drinking water for many years. Therefore, it may enter the food chain in the environment.
Trickling Filters and Membrane Bioreactors are focused on in this paper. Trickling Filters: Trickling Filter (TF) reactors consist of a vertical column packed with biofilm supporting media.
The bacteria and wastewater is mixed in an aeration tank and therefore the contaminants are removed by action of sorption and series of breakdown by the bacteria.
Bromine and Chlorine are the only two halogens currently used in flame retardants, making brominated and chlorinated flame retardants. These two elements have similar properties and mostly act the same way; they stop or interfere with the chemical mechanism that leads to the formation of flammable gases that ignite or sustain the flame. These FRs have a special property; they can be added to plastics and plastic foam without changing their properties.
Since 1-octanol was the least polar among 3 alcohols used in this part, so it was found to be insoluble in water but soluble in hexane. This was due to the longer chain of carbons makes compounds more hydrocarbon-like.
Aoki, T., Munemori, M.. Continuous Flow of Free Chlorine in Water. Journal of Analytical Chemistry. 1983, 55, 209-212
The basic set of reactions that involve this process are: Cl + O3 -->ClO + O2 and ClO + O -->Cl + O2 The net result: O3 + O -->2O2 Chlorine is initially removed in the first equation by the reaction with ozone to form chlorine monoxide. Then it is regenerated through the reaction with monatomic oxygen in the second equation. The net result of the two reactions is the depletion of ozone and atomic oxygen.6 Chlorofluorocarbons (CFCs), halons, and methyl bromide are a few of the ozone depletion substances (ODS) that break down ozone under intense ultraviolet light.
J. Clayden, N. Greeves, S. Warren, P. Wothers. Organic Chemistry. 8th ed. 2007, Oxford University Press, p. 1186-1191.