Advanced treatment and recycling process for wastewater containing heavy metal ions

Abstract

The invention discloses an advanced treatment and recycling process for wastewater containing heavy metal ions, which comprises the following steps of: primarily sedimenting wastewater of lead, zinc and other smelting enterprises respectively to remove most lead, zinc and arsenic in the wastewater; secondarily sedimenting to basically remove lead, cadmium, mercury, arsenic, zinc, copper, nickel, cobalt and other heavy metals in the wastewater; carrying out ceramic microfiltration membrane microfiltration treatment to remove SS in the wastewater to below 1mg / L so as to meet the requirement on quality of supplement water for circulating and cooling water, and the water is used as low-quality reuse water. The process disclosed by the invention is convenient to operate and manage, the operation is automatized, monitoring is easy to realize, the engineering investment and the operation cost are moderate, the heavy metal ion removal rate is high, and the process is easy to apply and popularize in the whole industry.

Description

technical field [0001] The invention belongs to the field of environmental protection, and in particular relates to advanced treatment and recycling process of waste water containing heavy metal ions produced by lead-zinc smelting enterprises. Background technique [0002] With the increasingly stringent requirements for the discharge of sewage and wastewater in lead and zinc smelting enterprises, the treatment of sewage acid wastewater generated in the process of smelting production has been paid more and more attention. The heavy non-ferrous smelting wastewater represented by lead and zinc mainly comes from the cooling drainage of furnace equipment, with a large discharge (about 40% of the total discharge); the discharge of flue gas washing and purification devices such as smelting and acid making, various heavy metals and A large amount of pollutants such as acids, alkalis and non-metals are discharged; the molten slag water quenching cooling water in the smelting process...

AI Technical Summary

Problems solved by technology

Therefore, the pH value control is a bit cumbersome, and the wastewater after treatment needs to be adjusted before it can be discharged.

[0009] (2) Sulfide precipitation method: adding sulfide to make the heavy metal ions in the wastewater generate sulfide precipitation and remove it. Compared with the neutralization precipitation method, the advantage of the sulfide precipitation method is that the solubility of heavy metal sulfide is higher than that of its hydroxide The solubility is lower, and the reaction pH value is between 7-9. Generally, the treated wastewater does not need to be neutralized, and the treatment effect is better, but the disadvantages of the sulfide precipitation method are: the sulfide precipitation particles are small, easy to form colloids, and the sulfide precipitation Residues in water will generate gas when encountering acid, which may cause secondary pollution

The existing advanced (reuse) treatment process for lead-zinc smelting wastewater also has problems such as long treatment process, unreasonable front-end treatment technology, cumbersome operation and management, difficulty in automatic operation and monitoring, and high investment and operation costs. It is difficult to implement and cannot become a process technology for advanced treatment or reuse treatment that is popularized and applied in the whole industry

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