In many production process, by using acid, alkali and salt, or in the production process of type produced acid, alkali and salt, and the resulting wastewater treatment by and with higher after the salt, the biochemical treatment had a bad influence, so this wastewater often become a problem.

For some of the activated sludge in without domestication, sodium chloride content more than 4000 mg/L began to show the active sludge inhibitory effect.

The waste water containing sodium chloride, generally has the following treatment: when in the waste water containing both organic, and contain chlorinated quantity and less than 2% time, generally USES the sewage diluted method or training special microorganism, because the toxicity of salty, the system to achieve high efficiency and stability operation is the more difficult and require operators have abundant operation experience, can happen in time the system the possible problems;

For only included the sodium chloride containing organic wastewater or not of the organic matter also contain concentrated with (more than 2%) of salt water, using sodium chloride wastewater treatment crystallization evaporator is the most stable and effective economic method.