1. Polishing the wastewater. During the process of the polishing on the parts, there will be abrasive materials and brightener existing in the waste water. The main pollutants are COD,BOD and SS. Refer to the following process procedures for treatment:
Wastewater → regulating tank→ coagu-flocculation reaction tank→ sediment tank→ hydrolysis acidification pool→ aerobiotic tank →secondary sedimentation tank→ filter →discharge
2. Remove oil and grease from the wastewater: The normal grease removal processes are: organic solvent degreasing, chemical degreasing, electrochemical degreasing, and ultrasonic wave degreasing. In addition to the organic solvent degreasing, other processes will contain degreasant such as alkaline matter, surface active agent and corrosion inhibitor, which will produce pollutants including pH, SS, COD, BOD, petroleum and chromaticity. Refer to the following steps to process:
Wastewater→ oil separator tank→ regulating tank →air-floatation equipment →anaerobic hydrolysis acidification →aerobicbiotreatment → sediment →filtration and adsorption →Discharge
This type of the wastewater normally contains emulsified oil. Add demulsifier of CaCl2 before air floatation to break the emulsified oil. If the COD concentration in the waste water is too high, anaerobic method can be selected. If it is not too high, choose aerobic biotreatment for the process.
3. Pickling waste water. Pickling waste water is often used in the acid pickling process for the steel parts. The PH value of the waste water is 2-3, with high concentration of Fe2＋ and SS. Refer to the following procedures for the treatment: wastewater→regulating tank→neutralizing tank→aeration oxidation pool→coagu-flocculation reaction tank→sediment tank→filter tank→pH value readjust tank→discharge The phosphating wastewater can also called membranadermalis wastewater, which means that iron parts will produce a layer of phosphateprotective film on its surface as the painting coatings after being chemical processed in the solutions of manganese, iron and zinc to prevent rust. The major pollutants in this kind of wastewater is : pH,SS,PO43－,COD, and Zn2＋. Refer to the following steps for the process: wastewater→regulating tank→primary coagu-flocculation reaction tank→sediment tank→ secondary coagu-flocculation reaction tank→secondary sedimentation tank→filter tank→discharge
4. The anodic oxidation wastewater for the aluminum. The main pollutants for this kind of the wastewater is pH,COD,PO43－ and SS. Apply the phosphating wastewater process tfor the anodic oxidation wastewater.
