tailieunhanh - Organic chemical contaminants in Biosolids

Certification informs the consumer of the undesirable and unobserved pesticides that may or may not have been used in the production of food. Thailand has multiple forms of organic regulations and certifying bodies. A standard and certification by the national government has issued only one label, called “Organic Thailand”, by the Department of Agriculture (DOA), when the gov- ernment set up standards for organic crop production in 2000 and developed a certification body for organic food products. The major certification body accredited by IFOAM is called “Organic Agriculture Certification Thailand” or ACT. . | Organic chemical contaminants in Biosolids Sally Brown University of Washington What are organic chemicals Organic chemicals or organics is the name for an enormous range of chemicals that have in common one central characteristic they contain the element carbon. Like all things that are made out of carbon organic contaminants will degrade over time to simple carbon dioxide. The time required to turn these compounds back to carbon dioxide will vary depending on the complexity of the compound. For example both a head of lettuce and the plastic bag that you put it in at the supermarket are organic carbon based materials. The lettuce will break down in a matter of days or weeks - as those of us who have been asked to clean out the vegetable bin in the refrigerator can attest. Plastics on the other hand can persist in the environment for decades. There are a wide range of chemicals that can be classified as organic. For example all plants animals and people are carbon based and can be classified as organic. Perfume shampoo and laundry detergent are also classified as organic. Carbon can bind to both itself as well as to other elements. Organic chemistry is the science that deals with the different types of organic compounds and explains their behaviors and persistence. The names of different organic chemicals are often derived from their differing carbon structures. For example trichloroethylene or TCE is an organic contaminant that in the past was commonly used as a solvent for industrial cleaning as well as by your neighborhood dry cleaner. The hazards associated with too much TCE in the environment were brought to light in the book A Civil Action by Jonathan Harr. The name of this chemical simply describes its structure it is an ethylene group with three chloride atoms attached to it trichloro . The chemical trichloroethylene is drawn above In many cases names of different organic chemicals are representative of different families of compounds. This is the same as .