Technology for recycling low-calcium and low-chlorine purified water

Abstract

The invention discloses a technology for recycling low-calcium and low-chlorine purified water after heavy-metal-containing wastewater is treated. A high-efficiency flocculating agent is added into the heavy-metal-containing wastewater; by acid-base adjustment, the pH is adjusted to be base, and solid-liquid separation is finally executed through an inclined plate settling basin so as to remove most heavy metal ions; supernate enters a buffering water basin for calcium reduction treatment and then enters an ultrafiltration-reverse osmosis system for advanced purification; produced fresh water serving as production water returns to a production system, and concentrated water serves as water for flushing residues. Part of bottom flow subjected to calcium reduction is used as crystal seeds for backflowing, and most of the bottom flow enters the buffering water basin for repeated use. The recycling rate of the recycled water is high; the phenomenon of calcium scaling is avoided; the wastewater treatment cost is low, and zero emission of the wastewater is realized.

Description

technical field [0001] The invention relates to a process for the treatment and reuse of heavy metal wastewater, in particular to a process for the treatment and recycling of wastewater containing one or more heavy metals such as cadmium, arsenic, lead, zinc, copper, etc. It belongs to the field of environmental engineering. Background technique [0002] The rapid development of industrialization has caused a large amount of heavy metal wastewater to be discharged into the environment. The acidic heavy metal wastewater has a low pH (pH value between 4-6) and contains a variety of heavy metal ions, such as Cu 2+ 、Cd 2+ , Pb 2+ , Zn 2+ 、As 2+ etc., they cannot be decomposed by organisms, and once they enter the environment, they will continue to accumulate in the environment, causing serious pollution to water bodies and even destroying the ecological environment. Many domestic smelting enterprises have purified water reuse systems, and the purified water treated by tradi...

AI Technical Summary

Problems solved by technology

These generated particles can strongly coagulate and adsorb organic or inorganic colloidal particles in wastewater, and at the same time, under the action of overvoltage, O 2 and H 2 , during its ascent process, the colloidal particles and oil slicks in the wastewater are adhered to float together, so as to achieve the purpose of removing heavy metal ions in acidic heavy metal wastewater. This method can also realize the reuse of low-calcium and low-chlorine purified water, but the cost At present, the application of electrochemical technology to treat acidic heavy metal wastewater at home and abroad is still relatively small.

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