Biosludge is released during the water purification of the process water of a rice processing producer. The incoming dirty water, the influent, is purified in a number of steps in the installation. The purified water is called the effluent. The coarser particles are removed successively with a grid or a separator, then the finer particles in settling tanks, and finally the dissolved substances. Apart from water, other substances are released, in particular sludge, the latter being marketed by AgriBioSource as Biosludge.