tailieunhanh - Resources/Waste: Home Chemicals

Organic farming is a growing sector in Thailand, which is encouraged by the government and many private initiatives. Therefore, production is expected to rise to meet the growing demand in the domestic market for organic foods. The increased range of healthy foods and the establish- ment of certificates for pesticide controlled vegetables indicate that there is a potential market. Consumers everywhere know very little about the production process, as there is no identifica- tion with the product and its producer. This might be true for Thailand as well, and therefore leads to low levels of confidence in organic production, which would indicate. | Resources Waste Home Chemicals Introduction Chemical Connections Chemicals are everywhere in the air you breathe in the food you eat and in the chair you re sitting on. Moreover you re mostly chemicals. Ninety nine percent of the human body is composed of just 6 chemical elements oxygen carbon hydrogen nitrogen calcium and phosphorus. After you die you ll decompose into hydrogen nitrogen water ammonia carbon dioxide phosphoric acid and sulfuric acid. So from chemicals we come and to chemicals we go. Fig. 1 Periodic Table NASA Chemical elements are substances that contain one kind of atom and cannot be separated into simpler substances. There are 116 known chemical elements of which 91 occur naturally. The other 25 are man-made. These elements are listed in the periodic table. Go to http reports periodic table . Scroll down below the table and you ll see the elements listed. Many of them will be familiar to you. Chemical compounds are formed by the combination of two or more elements. The one you re probably most familiar with is H20 two parts hydrogen and one part oxygen also known as water. Other common compounds include sodium chloride NaCl or salt glucose C12H22O11 or sugar and CH3COOC6H4COOH or aspirin. Chemicals are used in a wide range of industrial and commercial applications including plastics adhesives absorbents fertilizers detergents dyes explosives oils inks lubricants metals paper insecticides pharmaceuticals solvents waxes photography food additives and on and on. So you see chemicals are everywhere. There are several ways to classify chemicals. Organic chemicals are those chemicals that contain the element carbon C. Organic chemicals can be broken down by micro-organisms and reactions with other chemicals as well as photo chemically by ultraviolet or visible light. The rate at which a chemical degrades is expressed as half-life the amount of time it takes for half of the chemical to be converted into some other chemical or element. .