Anodizing Wastewater Treatment Line

Project overview

According to the information provided by Party A, Party A's production workshop plant to build a new oxidation production line (output 300t / month). In the process of production, there will be a certain amount of acidic wastewater, alkaline wastewater, wastewater containing nickel discharge. The wastewater contains a certain amount of oil, ammonia nitrogen, suspended matter and COD. According to the local environmental protection requirements, the waste water must be effectively treated before reaching the discharge standard. Party A attaches great importance to environmental treatment and hereby entrusts our company to formulate this plan.

Design Basis

1. Materials and sites provided by Party A.
2. Total production wastewater ≤230m³/d
3. Acid base wastewater discharge: ≤200m³/d.
4. Nickel containing waste water: ≤30m³/d.   
5. Instrcution:The above production wastewater is only the cleaning wastewater discharged from the water washing tank, excluding the tank discharge liquid.
6. There is no acid etching process and three acid polishing process in the oxidation production line.

Discharge Standards

According to the data provided by Party A, the wastewater discharged after treatment meets the requirements in the following table:

Ni Wastewater Treatment

1. Discharge of nickel containing wastewater: ≤30m³/d.
2. Emission requirements:According to the data provided by Party A, the pretreated nickel containing wastewater and comprehensive wastewater are mixed to meet the discharge requirements in Article 4 of the technical scheme.
3. The processing capacity of supporting equipment in this scheme is ≤30m³/d. Continuous treatment is adopted.
4. Treatment process flow:

5. Treatment process description

The nickel containing wastewater is discharged from the workshop and enters the sump. After homogenization in the sump, the wastewater is pumped to the duplex reactor, and the reducing agent is added to the reactor to fully stir the reaction.Then add alkali to adjust the pH value of the wastewater to alkaline, and add PAM to make the wastewater produce flocculent precipitation (also known as alum). After the dosing reaction, the wastewater flows into the sedimentation tank by itself. In the sedimentation tank, suspended matter with a specific gravity greater than water settles to the bottom of the tank to form sludge, and the supernatant automatically flows to the alkaline wastewater tank for further treatment.

The sludge at the bottom of the sedimentation tank is regularly discharged to the sludge concentration tank, and then the sludge is pumped to the filter press by the sludge pump for dehydration treatment. After dehydration, the dry sludge is bagged and entrusted to a qualified unit for outward treatment, so as to avoid secondary pollution caused by improper sludge treatment.The filtrate enters the filtrate pool and is pumped to the duplex reactor for reprocessing.

6. Expected treatment effect

When the equipment is in normal operation, the discharge outlet index for the mixed treatment of nickel-containing wastewater and comprehensive wastewater after treatment meets the requirements of 2 of this Part.