Náročnosť v schôdzi the štandardoch pre čistenie z galvanické pokovovanie odpadová voda z elektrické kúrenie rúrky

At present, the treatment of electroplating wastewater adopts the following methods: chemical precipitation method (including reduction treatment of chromium containing wastewater and oxidation treatment of cyanide containing wastewater), ion exchange method, and membrane ion separation method. For wastewater from small and medium-sized electroplating enterprises, the conventional treatment process is to divide the wastewater into chromium containing wastewater, cyanide containing wastewater, and other heavy metal wastewater (including nickel containing wastewater, copper, etc.). The chromium containing wastewater is first reduced and then neutralized and precipitated. The cyanide containing wastewater is treated with secondary oxidation and then neutralized and precipitated together with other heavy metal wastewater. The effluent is filtered and discharged. There are also methods of adding heavy metal collectors to improve the removal rate. The use of the above processes often leads to excessive levels of copper, nickel, and COD, mainly due to:

1. Existuje je nie klasifikácia zber z odpadových vôd alebo the klasifikácia zber metóda je neprimeraná. Mnohé galvanické pokovovanie rastliny použitie zmiešané čistenie, ktoré nie len má vysoká čistenie náklady ale tiež nemôže povoliť rôzne kovy ióny do zrazeniny pod the optimálne pH podmienky, konečne vedúce k na jeden alebo dva kov ióny prekročenie the standard. The čistenie z galvanické pokovovanie odpadová voda všeobecne vyžaduje the princípy of klasifikované zber a kvalitatívne ošetrenie.

2. The existing electroplating wastewater treatment facilities are relatively backward, and many enterprises use manual operations. Therefore, the adjustment of pH and the addition of various chemical agents are not precise, and there are many human factors, resulting in low compliance rates.

3. Inaccurate pH control. The existing Ph/ORP control generally adopts switch quantity or PID control. Due to the severe nonlinearity and delayed characteristics of the Ph/ORP process, the pH deviation is large, usually reaching ± 0.5~1.0. If the pH value is required to be controlled at 9.5, but the actual results fluctuate between 8.5~10.0, resulting in poor neutralization and precipitation effect of heavy gold ions.

4. Among various heavy metals, Cu2 plus is most likely to exceed the standard due to the presence of various complex compounds, which cannot be treated by precipitation method. However, most of the existing treatment processes do not have a breakdown process, so exceeding the standard is inevitable.

5. In addition, from the perspective of engineering implementation, although the water volume of small electroplating plants is small, there are many types and the water quality is complex, but the engineering quantity is small. Therefore, professional environmental protection companies with strong technical strength are unwilling to undertake such small environmental protection projects, while small companies lack technical characteristics due to insufficient technical strength, and some do not even have basic analysis and testing instruments, so they are unable to do the project well. In the end, although the manufacturer spent money and the engineering cost was relatively low, they were unable to ensure that the effluent met the standard, especially after long-term continuous operation.