Electroplating factory effluents ( or workshop ) and waste, such as plating rinse water, waste liquid, cooling water and rinse water, the water quality due to the production process varies, some containing chromium, some containing nickel or cadmium, cyanide, acid, alkali and other content. Metal ions in waste water with simple cation some form ( such as Ni2+, Cu2+ etc.), some with anions form ( such as CrO Han etc.), some are in the complex anion form [ such as Au ( CN ), Cd ( CN Han entertainment ), Cu (P2O7 ) ] Yong etc.. A wastewater often contains more than one harmful ingredients, such as cadmium cyanide plating waste water with cyanide and cadmium in. In addition, the general in the plating solution containing organic additive constant.

Electroplating wastewater more toxic, harmful. Such as cyanide can cause human and animal acute poisoning, mortality, long-term effect of low concentration can also cause chronic poisoning. Cadmium can cause kidney disease, and may cause Itai-itai disease. Six prices chromium can cause lung cancer, gastrointestinal disorders and anemia, and will in the bone, spleen and liver volume. Therefore, electroplating waste water must be controlled strictly, properly handle.

Electroplating wastewater treatment have been several decades of history, can be divided into three stages: the first stage, generally in the nineteen fifties, mainly focused on waste water, waste residue processing technology. The main object for cyanide and Cr six. Treatment is the main method of chemical precipitation method. The second stage is in roughly 60 years, began to pay attention to reform process and comprehensive utilization, and deal with cadmium and other metal. Third stage since 70 time, begin to study the fundamentally pollution control technology, give priority to in case, reform the electroplating process, study of closed circulation of wastewater from. In the reform process with low concentration process instead of high concentration process ( such as low chromium instead of high chromium plating ), with non-toxic or less toxic materials electroplating process instead of toxic materials (such as cyanide free technology for cyanogen craft ). The following method for treatment of electroplating wastewater:

Chemical method

The addition agent to the waste water, the toxic substances into non-toxic substances or toxicity is reduced greatly.

Evaporation condensation method

Using the heat source and the evaporator at atmospheric pressure or negative pressure directly concentrated wastewater. Treatment of high concentration wastewater with the method of comparative economic, often with three stage countercurrent rinsing, gas water spray, or with ion exchange method combined use. Currently widely applied in production of titanium tube evaporator and evaporator to concentrate of chromium-containing wastewater, wastewater containing cyanide, is also the primary processing of closed cycle.

Prospects of electroplating wastewater treatment technology development prospects, is first compressed content, widespread popularization of countercurrent rinsing and spraying technology; secondly, by chemical sludge and ion exchange resin regeneration waste water comprehensive utilization, and applied to the development of electroplating wastewater treatment with a variety of high-quality resin and membrane, and the further research and perfection of the circulatory system, in order to to achieve full utilization of resources.