There are many kinds of electroplating production process, due to different electroplating processes, the resulting waste water is also different, the general discharge of wastewater from electroplating enterprises including acid, alkali and other pre-treatment wastewater, cyanide cyanide copper-containing wastewater, copper-containing wastewater , Nickel-containing wastewater, chromium-containing wastewater and other heavy metal wastewater. In addition there are a variety of plating waste generated.
For different types of pollutants containing electroplating wastewater have different treatment methods, are mainly introduced the following use of UV disinfection or sterilization of UV disinfection process:
1. Cyanide wastewater UV disinfection process
The current treatment of cyanide-containing wastewater is relatively mature technology is the use of alkaline chloride treatment, we must pay attention to cyanide wastewater and other wastewater to be strictly shunt to avoid mixing with nickel, iron and other metal ions, or difficult to handle. The principle of the method is that the wastewater is treated under alkaline conditions by a chlorine-based oxidant to destroy and remove the cyanide. The treatment process is divided into two stages. The first stage is the oxidation of cyanide to cyanate and the incomplete destruction of cyanide , Called incomplete oxidation stage, the second stage is to further oxidize and decompose cyanate into carbon dioxide and water, called the complete oxidation stage.
Treatment process: Cyanide-containing wastewater → Regulating pool → first grade cyanide pool → second grade cyanide pool → inclined sedimentation tank → filter tank → callback pool → UV disinfection equipment (UV sterilizer or UV sterilizer) → after discharge treatment Cyanide-containing wastewater mixed with electroplating wastewater treatment together.
2. chromium wastewater UV disinfection process
Containing hexavalent chromium wastewater is generally treated by chromium reduction method, the principle of the law is added under acidic conditions, reducing agent ferrous sulfate, sodium sulfite, sodium bisulfite, sulfur dioxide, the hexavalent chromium reduced to trivalent chromium, Then add sodium hydroxide, calcium hydroxide, lime and other pH adjustment, to generate trivalent chromium hydroxide precipitate from the wastewater separation.
Process: Cr6 + wastewater treatment → regulating tank → reduction reaction tank → coagulation reaction tank → sedimentation tank → filter → pH callback tank → discharge.
3. Integrated UV disinfection of heavy metal wastewater disinfection process
Integrated heavy metal wastewater is composed of non-complex heavy metal wastewater containing copper, nickel, zinc and acid, alkali pre-treatment wastewater. Such wastewater treatment is relatively simple, generally used under alkaline conditions generated hydroxide precipitation process for processing. Process: Integrated heavy metal waste water → regulating pool → quick mixing tank → slow mixing tank → inclined tube settling tank → filtration → pH callback pool → UV disinfection equipment (UV sterilizer or UV sterilizer) → discharge.
4. A variety of electroplating wastewater comprehensive treatment of ultraviolet disinfection process
When a electroplating plant contains a variety of electroplating wastewater, such as cyanide-containing wastewater, wastewater containing hexavalent chromium, acid and alkali, heavy metals such as copper, nickel, zinc and other integrated wastewater, wastewater diversion treatment generally take the first cyanide wastewater containing chromium Wastewater should be separately diverted from the production line and collected, respectively, in accordance with the corresponding method for the treatment of cyanide-containing and chromium-containing wastewater, the treated wastewater mixed with the integrated wastewater, coagulation and sedimentation together with the follow-up treatment.
Process: Cyanide-containing wastewater → regulation pool → a broken cyanide tank → two broken cyanide pool → comprehensive wastewater tank. Chromium-containing wastewater → regulating tank → chromium reduction tank → integrated waste water tank. Integrated wastewater → Integrated wastewater tank → Quick mixing tank → Slow mixing tank → Inclined pipe settling tank → Intermediate tank → Filter → pH callback tank → UV disinfection equipment (UV sterilizer or UV sterilizer) → Emission.
Article from NdFeB Industry Network