Solid waste policy in the United States produce large amounts of waste in small areas. For example, EPA reports that a single dairy cow produces approximately 120 pounds of wet manure per day equaling to that of 20-40 people. The main problems of animal waste mismanagement are environmental, especially water pollution. Industrial waste consists of a significant amount of solid waste. EPA reported that each year United States industrial facilities generate and dispose of approximately 7.6 billion tons of industrial solid waste based on 1980s figures. This figure includes waste generated from 17 industrial manufacturers of organic chemicals, inorganic chemicals, iron and steel, plastics and resins, stone,
Air changes per hour the airflow efficiency of the enclosure and the methods used to ventilate it. The actual amount of air changed in a well mixed ventilation scenario will be 63.2% after 1 hour and 1 ACH. In order to achieve equilibrium pressure, the amount of air leaving the space and entering the space must be the same. formula_1 Where: Ventilation rates are often expressed as a volume rate per person (CFM per person, L/s per person). The conversion between air changes per hour and ventilation rate per person is as follows: formula_2 Where: Air change rates are often used as rules of