Liquid radioactive waste generated at nuclear power plants usually contains soluble and insoluble radioactive components (fission and corrosion products) and nonradioactive substances. The general objective of waste treatment methods is to decontaminate liquid waste to such an extent that the decontaminated bulk volume of aqueous waste can be either released to the environment or recycled. Waste concentrate is subject to further conditioning, storage, and disposal. Because nuclear power plants generate almost all categories of liquid waste, nearly all processes are applied to treat radioactive effluents. Standard techniques are routinely used to decontaminate liquid waste streams. Each process has a particular effect on the radioactive content of the liquid. The extent to which these are used in combination depends on the amount and source of contamination. Four main technical processes are available for treatment of liquid waste: evaporation; chemical precipitation/flocculation; solid-phase separation; and ion exchange.