1 For a 2-hour party, Cork Catering in Illinois charges $7.50 per guest for beer or wine only and $14.50 per guest for a premium bar serving most types of mixed drinks. 2  For detailed open bar pricing, see How Much Does an Open Bar Cost. For a 2-hour party, Cork Catering in Illinois charges $7.50 per guest for beer or wine only and $14.50 per guest for a premium bar serving most types of mixed drinks. 2  For detailed open bar pricing, see How Much Does an Open Bar Cost.
Selenium exists in a number of allotropic forms. Allotropes are forms of an element with different physical and chemical properties. One allotrope of selenium is an amorphous red powder. A lump of clay is an example of an amorphous material. A second allotrope of selenium has a bluish, metallic appearance.
icity and transport properties of arsenic strongly depend on their chemical form. The forms of arsenic occur with valance states of â3, 0, 3, and 5. Most arsenic exists as arsenite (AsO3 3, As(III)) and arsenate (AsO3 4, As(V)) in water [3], and As(III) is more toxic than As(V). Meanwhile, selenium is a natural trace element, known to be an essential nutrient for animals and humans. Selenium contamination in drinking water is currently of concern because of the narrow range between selenium deï¬ciency and toxicity to humans [4,5]. Selenium is introduced into water from various sources including agricultural activities, fossil fuel combustion, and other industrial efï¬uents [6]. Selenium exists in valance state of â2, 0, 4, and 6 and has several organic forms [7]. Because higher valance forms of selenium are more water soluble, selenite (SeO2 3, Se(IV)) and selenate (SeO 2 4, Se(VI)) are the predominant forms found in water, and Se(IV) is more toxic than Se(VI) [5,8]. The United States Environmen-tal Protection Agency has established the maximum