batch leaching

A leaching test that estimates how readily contaminants could mobilize out of a solid waste or other solid material if the material comes into contact with natural waters. The test involves placing a given mass of the solid sample in a container with a specific volume of a liquid leaching solution. The leaching solution may be water, salt buffers, acidic solutions, basic solutions, or organic solvents. The mixture is agitated for a specific amount of time (usually, hours to days). Afterwards, the mixture is filtered and the liquid (the leachate) is analyzed for contaminants, such as arsenic. A common batch leaching method is the US Environmental Protection Agency’s toxicity characteristic leaching procedure (TCLP), which is used to determine whether a solid or liquid waste has the toxicity characteristic of hazardousness (compare with leaching, leaching test, column leaching, sequential batch leaching, and serial batch leaching).