A method for treating spray paint wastewater

Abstract

The invention relates to the field of wastewater treatment, in particular to a method for treating spray paint wastewater, comprising the following steps: 1) passing the wastewater through a grid to remove suspended matter, and staying in the first treatment liquid obtained after aeration; Add a pH regulator to adjust the pH value to obtain the second treatment solution; 3) add soluble superphosphate to the second treatment solution for the first stirring reaction to obtain the third treatment solution; 3) add sub The iron salt solution is stirred for the second time to obtain the fourth treatment solution; 5) adding a coagulant to the fourth treatment solution and stirring for the third time, then adding a coagulant and stirring for the fourth time, and standing for stratification; 6) Remove the suspended matter in the upper layer after static stratification in step 5), and clear the lower layer to be discharged or recycled. In the present invention, the spray paint wastewater has a good treatment effect through the above treatment method, and the waste water has a high viscosity-breaking efficiency, which can effectively improve the waste water and make the COD in the paint spray wastewater Cr The value is less than 100mg / L, reaching the third grade standard of GB8978‑1996.

Description

technical field [0001] The invention relates to the field of wastewater treatment, in particular to a method for treating spray paint wastewater. Background technique [0002] Painting wastewater mainly comes from the water used in wet spray booths or the process of painting workpieces. Paint spray wastewater contains a large amount of suspended solids such as resins, surfactants, organic solvents and additives, and macromolecular organic substances that are difficult to biodegrade. The composition of pollutants is relatively complex and the recyclability is poor. At present, the traditional methods for treating spray painting wastewater are dilution method and coagulation method. However, due to the large volume of wastewater to be treated after dilution, a large amount of chemicals need to be added, so the treatment cost is high, and it is not suitable for large-scale application. The coagulation method is to directly add coagulant and flocculant to the spray paint wastew...

AI Technical Summary

Problems solved by technology

Paint spray wastewater contains a large amount of suspended solids such as resins, surfactants, organic solvents and additives, and macromolecular organic substances that are difficult to biodegrade. The composition of pollutants is relatively complex and the recyclability is poor.

At present, the traditional methods of treating spray painting wastewater are dilution method and coagulation method, but because the volume of wastewater to be treated after dilution is too large, a large amount of chemicals need to be added, so the treatment cost is high, and it is not suitable for large-scale application

The coagulation method is to directly add coagulant and flocculant to the spray paint wastewater for coagulation treatment, but the quality of the effluent water is difficult to meet the safety discharge standard. The present invention solves the existing problems by configuring a method that can eliminate the viscosity of water-soluble and fat-soluble paints and has a good A spray paint wastewater treatment agent with good coagulation effect, a treatment method that reduces the cost of the agent, can effectively improve the wastewater, and make the effluent quality meet the standard