Photovoltaic waste water mainly comes from auxiliary waste liquid and cleaning waste water produced by silicon rod cutting, grinding, slicing and silicon wafer grinding, corrosion, polishing and other processes. Its treatment difficulties mainly include: organic matter (mainly polyethylene glycol, etc.), suspended matter (mainly silicon powder, silicon carbide) have high concentration, and contain fluorions, acid and alkali (mainly hydrofluoric acid, nitric acid and other buffer acids) and other pollutants. After testing the samples, the laboratory of our company found that the main pollution factors were fluorine ions, COD and pH value. The fluorine ions in the waste water mainly come from the hydrofluoric acid used in the production process; the organic pollution components in the waste water mainly come from isopropyl alcohol and acetone used in the cashmere tank (the discharge frequency is very small ); acid-base Ph pollution factors are mainly hydrofluoric acid, hydrochloric acid, nitric acid and sodium hydroxide used in production. Therefore, after dozens of tests and cooperating with the customer's original treatment equipment, the following scheme is finally given: adjust the PH of the sewage hydrolysis acidification tank, and then adjust the organic matter through the MBR tank of the aerobic tank, the sludge that can pass through the filter press is finally formed. Acid-resistant materials are used when the filter press selects materials to prolong the service life of the filter press.
