What is the difference between the feed rate and the capacity of the carbon?
The feed rate is the rate at which wastewater enters the activated carbon adsorption unit. It is a unit of flow (i.e., volume per unit time), such as gallons per minute or liters per second. The feed rate should allow the wastewater sufficient time to contact the carbon so that contaminants can be adsorbed onto the carbon. If the feed rate is too high, pesticide active ingredients will pass through the carbon adsorption system that otherwise could have been adsorbed. During its treatability testing, EPA used a feed rate that gave the wastewater an empty bed residence time of approximately 15 minutes. The capacity is the amount of pesticide active ingredient that will be adsorbed per amount of carbon. It is usually given in units of weight of pesticide active ingredient removed per weight of carbon, such as grams of pesticide active ingredient removed per gram of carbon. Determining the capacity can help one determine how much carbon is needed in the unit to remove a particular amount o
