Treatment method for waste water containing mercury in PVC production through calcium carbide process

Abstract

The invention relates to a treatment method for waste water containing mercury in PVC production through a calcium carbide process. The treatment method comprises the following steps that the waste water containing the mercury is collected into a sedimentation basin, large-grain sediments in the waste water are subjected to sedimentation treatment, waste water containing the mercury after sedimentation treatment is pumped into a filtering pretreatment device to conduct filtering pretreatment through a conveying pump, waste water containing the mercury after filtering pretreatment is conveyed into a coagulating sedimentation reactor, a sodium sulphide solution and an inorganic flocculant are successively added into the coagulating sedimentation reactor, and HgS flocculent precipitation is generated and naturally precipitated; filtering clear liquid after reaction sedimentation is conveyed into an ultrafiltration device, the filtering clear liquid sequentially passes through a mercury-removing resin film and a material filling column loaded with mercury-removing filling and is subjected to joint absorption treatment of inorganic mercury and organic mercury again, and ultrafiltration clear liquid is generated; and the ultrafiltration clear liquid is conveyed into a saline water separation device to conduct concentration desalination, and finally, fresh water which conforms to the national standard is discharged into a water storing tank to store for later use through a saline water separation device.

Description

technical field [0001] The invention relates to the technical field of treating mercury-containing wastewater, in particular to a method for treating mercury-containing wastewater in calcium carbide process PVC production. Background technique [0002] Polyvinyl chloride (PVC) is one of the five general-purpose plastics. It is widely used in important fields such as industry, agriculture, national defense, and chemical building materials. It is an important product of "replacing steel with plastic and wood with plastic". It is one of the important products of modern society and occupies an important position in the national economy. In my country, the production of polyvinyl chloride mainly adopts the calcium carbide method and mainly uses the acetylene raw material route. In the production process of PVC by the calcium carbide method, the catalyst used in the synthesis of vinyl chloride is activated carbon as the carrier impregnated with 10%-12% mercuric chloride. In this...

AI Technical Summary

Problems solved by technology

The mercury content in the generated wastewater is unstable, and it also contains a large amount of inorganic salts and various impurities. The water quality components are very complex, and the treatment is difficult, which has a certain impact on the clean production of the enterprise.

It can be seen that the production of calcium carbide PVC leads to a large amount of mercury emissions and mercury pollution. Mercury pollution is persistent, bioaccumulative, and biomagnifying, which has a great impact on the environment and human health.