Method for treating electroplating wastewater based on low voltage pulsed electric flocculation technology

Abstract

The invention discloses a method for treating electroplating wastewater based on low voltage pulsed electric flocculation technology. The method comprises the following steps: treating electroplating wastewater by pulsed electric flocculation technology, wherein the time for the treatment is 20 min to 60 min, pulse power supply is an industrial-frequency alternating current of 220 V and 50 Hz, output voltage of the pulse power supply is 0 to 36 V, duty ratio is 10% to 90%, output frequency is 100 Hz to 1000 Hz, output current density is 0.5 A / dm<2> to 3.5 A / dm<2>, the anode of the electric flocculation is aluminum electrodes, the cathode is stainless steel electrodes, and the distance between plate electrodes is 1 cm to 10 cm; adding lime into the electroplating wastewater treated by pulsed electric flocculation to adjust the pH value of the wastewater to be 7.4, wherein the weight ratio of lime to the treated wastewater is 1:200 to 1:40; adding diatomite into the solution, wherein the weight ratio of diatomite to the electroplating wastewater treated by pulsed electric flocculation is 1:200, standing the solution for deposition, and discharging or recycling the electroplating wastewater. The method provided in the invention is simple and easy to implement and enables low cost and high efficiency; treated wastewater can be reused or discharged directly.

Description

technical field [0001] The invention relates to a method for treating electroplating wastewater, in particular to a method for treating electroplating wastewater based on low-voltage pulse electrocoagulation technology. Background technique [0002] Electroplating is highly versatile and widely used in industry. Almost all industrial sectors have electroplating factories. According to statistics, the number of electroplating sites in the country has grown to nearly 20,000, and the consumption of water resources has also increased. On average, each electroplating point uses 200m water per day 3 It is estimated that the annual discharge of wastewater in the country will exceed 1 billion m 3 . More than 90% of electroplating wastewater comes from the cleaning process of plating parts. The reuse rate of electroplating cleaning water is very low, and the wanton waste of water is very common. The water quality of electroplating wastewater is complex, and its composition is dif...

AI Technical Summary

Problems solved by technology

These two methods have low equipment efficiency, high processing costs, and complicated post-maintenance

[0004] Electrocoagulation technology has the advantages of no need to add chemicals, low cost, no or little secondary pollution, and less sludge generation. Increased maintenance costs for electrode replacement

[0005] Pulse electrocoagulation technology can effectively slow down electrode scaling and save power consumption. When this technology is used for wastewater treatment, the pulse power supply voltage used is high (up to 300~500V), which is much higher than the safe voltage of 36V. When treating wastewater, the surrounding area is prone to moisture and water seepage, which can easily cause electric shock to the operator, posing a great safety hazard