Heavy metal recovery process for treating low-concentration plating heavy metal wastewater

Abstract

The invention discloses a heavy metal recovery process for treating low-concentration plating heavy metal wastewater. The process comprises the following steps: pumping unpretreated low-concentrationheavy metal wastewater into membrane treatment equipment by a pump, wherein the wastewater contains heavy metal ions, COD (Chemical Oxygen Demand), NH4 and complexes, and the filtering precision of the membrane is 0.01 micron; removing suspended solids, colloid and organic matters, enabling membrane equipment effluent to enter heavy metal adsorption equipment to adsorb copper ions, washing out heavy metal ions by acid regeneration after the adsorbed filter material is saturated, enabling regenerated liquid to enter metal electrolysis equipment to be electrolyzed into sheet metal to be recovered after the ion concentration reaches a certain number, returning the electrolyzed regenerated liquid to recycle, adding a new acid to supplement when the concentration is not enough, regulating the pH value of the adsorption equipment effluent to 7-8, and performing biochemical treatment to remove the heavy metals. According to the wastewater treatment process, since the heavy metals are removedby adopting an adsorption method, the amount of heavy metal sludge is reduced, the sludge treatment cost is saved, and valuable metals in the wastewater are recovered, so that recycling is realized, and the whole wastewater treatment cost is saved.

Description

technical field [0001] The invention belongs to the field of environmental protection, and more specifically relates to a heavy metal recovery process for low-concentration electroplating heavy metal wastewater treatment. Background technique [0002] Most of the existing heavy metal wastewater is treated by chemical dosing. In order to remove a small amount of heavy metals in the wastewater, a large amount of lime, ferrous, sulfide coagulant, etc. are added. The treatment cost is high, and the generated sludge is large. 100 grams of heavy metal 4,000-5,000 grams of sludge is produced. Based on a daily treatment of 1,000 tons of wastewater, the sludge produced per day is about 5 tons, and the treatment cost is 2,000-3,000 yuan per ton. After the waste treatment company collects the sludge, it is difficult to deal with heavy metals in subsequent treatment It is difficult to recycle, and the generated sludge is mostly disposed of by landfill. With the acceleration of technolog...

AI Technical Summary

Problems solved by technology

Practice has proved that the resource utilization of sludge is an inevitable way out for sludge treatment. However, more than half of the heavy metals in the sewage treatment process will be transferred to sludge worms. The heavy metals in sludge have seriously hindered the resource utilization of sludge.

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