KR960009377B1 - Apparatus and method for waste water treatment by combined system with reverse osmosis and pelite - Google Patents

Abstract

passing the waste water through a sand filter(1) and a micro filter(2) to remove solid matter, sand, and dust; passing the waste water through ultrafilter(4) to remove organic substance; gettering the waste water in a storage tank(5), adjusting pH, and sending it to a reverse osmosis(7) device; reusing the waste water passed through the reverse osmosis device(7) as gilding water, and condensing heavy metal ions in a ferrite reaction device(9) after setting the temperature of the ferrite reaction basin(8) at 60 -90 deg.C and putting in Fe(II) or Fe(III) and alkalis like NaOH, blowing air in to oxidize the Fe and make ferrite powder, and separating out the powder through a magnetic separator(10).

Description

Plating wastewater treatment method and apparatus by hybrid system of reverse osmosis pressure and ferrite method

1 is a conceptual diagram of an apparatus for carrying out the method of the present invention.

2 is a test graph (zinc removal rate) of the results of the present invention.

3 is a test graph of the results of the present invention (zinc ferrite recovery).

The present invention relates to a plating wastewater treatment method and apparatus by a hybrid system of reverse osmosis and ferrite method, and more particularly, the permeated water obtained by treating the plating wastewater generated by the plating process with reverse osmosis is reused as the plating wash water. In addition, the concentrated heavy metal ions are a non-discharge method which is a hybrid system by reverse osmosis and ferrite method in which the plating wastewater is not discharged out by recovering the ferrite powder by the ferrite method and the apparatus for performing the same.

The plating wastewater generated after plating in the plating industry is currently treated by sedimentation agglomeration, and heavy metals are sludged, and the filtrate after sludge is filtered is discharged. The current precipitation coagulation method is expensive to install and contains heavy organic ions, surfactants, and brighteners as well as heavy metal ions in the plating wastewater, making it difficult to completely settle and use many chemicals to treat them. In addition to the above problems, the precipitation flocculation method generates chemically unstable sludges of about 100 times the heavy metal ions due to the use of many chemicals after treatment, and there is a possibility of soil and water pollution due to heavy metal re-dissolution by landfill.

In order to solve such a conventional crystal, the present invention treats the plating wastewater having a low concentration of heavy metal ions generated by washing and washing with reverse osmosis so that the plating wastewater is not discharged out. Heavy metal ions, such as these, are sent to the ferrite process and recovered as ferrite powder, thereby enabling an environment-free pollution-free process.

Hereinafter, the present invention will be described in detail with reference to FIG. 1 as a process apparatus.

Process

When the plating wastewater is discharged, the solids, dust and sand are removed through a sand filter 1 and a micro filter 2. 4 is an ultrafilter to remove fouling, one of the biggest obstacles in reverse osmosis membranes, by removing surfactants and chelating compounds, which are organic compounds that are not removed by 1 and 2. The washing water in the washing tanks 3 and 6 serves to wash the membrane by flowing the washing water backward to the ultrafiltration membrane and the reverse osmosis membrane, respectively. Plating wastewater discharged from the ultrafiltration membrane apparatus of 4 is collected in the storage tank 5, and then the pH of the solution is adjusted to the reverse osmosis apparatus 7. Here, the permeated water that has passed through the reverse osmosis membrane in the plating wastewater is reused as plating water, and the concentrated heavy metal ions are sent to the ferrite reactor 9. The reaction temperature of the ferrite reactor is about 60-90 ° C, and an appropriate amount of Fe (II) or Fe (III) and alkali such as NaOH are added in an equivalent amount, and oxygen is blown to produce ferrite powder by oxidizing Fe (II). The ferrite powder is separated using a magnetic separator 10 and dried in a dryer 11.

Example

The turbidity of the permeate obtained by treatment of zinc-plated wastewater with a zinc concentration of 58 ppm, pH 2.2, and turbidity of 10 with microfiltration, ultrafiltration, and reverse osmosis was measured, and the turbidities were 4.2, 1.5, and 0.5, respectively. As a result of treatment with reverse osmosis device, zinc removal rate was more than 99.9% at pH 8.0 or above.

Zinc ferrite was added at a reaction temperature of 80 ° C, pH9.0-10.0, and Zn / Fe molar ratio of 0.5-0.6. (Figure 3)

Therefore, the present invention can contribute to environmental protection by making it widely practical in the field of plating industry, which is currently a major factor in the pollution problem.

Claims (2)

The permeated water obtained by treating the plating wastewater generated during the plating process by reverse osmosis method is reused as the plating wash water, and the concentrated heavy metal ions are recovered as ferrite powder by the ferrite method, so that the plating wastewater is not discharged out. Plating wastewater treatment method by a hybrid system of reverse osmosis and ferrite method. Connected to the ultrafilter 4 through the sand filtration device 1 and the precision filtration device 2, and the rinsing water in the cleaning tanks 3 and 6 is installed in the ultrafiltration membrane and the reverse osmosis membrane, respectively. Connect it to the storage tank 5 and connect it back to the reverse osmosis system 7, where the permeated water that passed through the reverse osmosis membrane in the plating wastewater is reused as plating water, and the concentrated heavy metal ions are connected to the ferrite reactor 9, and then through the magnetic separator 10. Plating wastewater treatment apparatus by a hybrid system of reverse osmosis and ferrite method, characterized in that connected in the dryer 11.