Electroflocculation device and method for treating heavy metal ion wastewater

Abstract

The invention discloses an electroflocculation device and method for treating heavy metal ion wastewater. The electroflocculation device comprises an electrolytic cell for storing the heavy metal ionwastewater, a cathode and an anode are arranged in the electrolytic cell, the anode is connected with a positive electrode of a voltage-stabilized direct-current power supply arranged outside the electrolytic cell, and the cathode is connected with a negative electrode of the voltage-stabilized direct-current power supply. The method comprises the steps that the pH value of the heavy metal ion wastewater is adjusted to be 6-9 by using NaOH, the electric conductivity of the heavy metal ion wastewater is adjusted to be 3 ms / cm by using NaCl, then the current density of the voltage-stabilized direct-current power supply is adjusted to be 5 A / dm<2>, the voltage-stabilized direct-current power supply is connected, and the heavy metal ion wastewater is treated for 30 minutes, so that heavy metals in the heavy metal wastewater are converted into floccules for separation. Compared with the prior art, the electroflocculation device and method have the advantages that the heavy metal ion wastewater is treated by utilizing an electroflocculation technology, the fact that the heavy metal ion removal rate is the highest, can be 95% or above, is verified under the conditions that the pH value ofthe heavy metal ion wastewater is within the range of 6-9, the distance between plate electrodes is about 2 cm, the electrolysis treatment time is controlled to be about 30 min, the current density is 5 A / dm<2> and the conductivity is controlled to be 3 ms / cm.

Description

technical field [0001] The invention relates to the field of metal ion wastewater treatment, in particular to an electroflocculation device and method for treating heavy metal ion wastewater. Background technique [0002] In today's society with rapid progress and development, as people's demand for various resources gradually increases, the supply of resources on the earth is becoming more and more tense, and the problem of water resources is more prominent. Nowadays, the problem of water resources has attracted the attention of all countries. Human survival and development are inseparable from water. The quality of water has an important impact on human health and living conditions. According to statistics, my country's water resources are extremely scarce, and the per capita water resources are 0.22×10 4 m 3 , probably only a quarter of the world's average level of water resources. Moreover, the distribution of fresh water resources in our country varies greatly. The s...

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Problems solved by technology

[0007] (1) When electrocoagulation is used for sewage treatment, the cathode of the electrode is prone to passivation, resulting in the formation of a dense oxide film on the surface of the electrode, which not only increases the energy consumption of the treatment, but also hinders the reaction of electrocoagulation, and ultimately reduces the The ability to purify sewage

[0008] (2) Electrocoagulation technology requires high energy-consuming electricity, and it is difficult to promote and apply electrocoagulation technology in areas where power supply facilities are relatively backward

[0009] (3) The conductivity of sewage is an important factor affecting the electrocoagulation reaction. The efficiency of electrocoagulation treatment of sewage containing solids with low solubility is not high because of its weak conductivity.

[0011] (5) Some hydroxide flocs are dissolved in sewage in some cases and cannot be completely removed by coagulation

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