JPS5944919B2 - How to remove heavy metals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adsorbing and removing heavy metals such as chromium, vanadine, arsenic, molybdenum, and tungsten that exist as anions in wastewater.

More specifically, heavy metals in wastewater are characterized in that anionic heavy metals in wastewater are adsorbed using an iron plate chelate resin having an iron base of iminopropionate and/or iron base of iminodipropionate as a chelate-forming group. This relates to a removal method.

Normally, many heavy metals such as mercury, copper, cadmium, zinc, lead, silver, nickel, and cobalt often exist as cations in solution, and are processed using neutralization coagulation precipitation method, sulfide precipitation method, and ion flotation method. , ion exchange resin method, activated carbon adsorption method, etc.

However, chromium, vanadine, arsenic, molybdenum,
Heavy metals such as tungsten tend to exist as anions in solutions and are extremely difficult to remove using the treatment methods described above.

In view of this situation, the present inventors have developed a method for removing heavy metals such as chromium, vanadine, arsenic, molybdenum, and tungsten, which are present in the form of anions in wastewater, using a simple device, easy to operate, and effective. As a result of intensive research to find a method that can reliably remove these heavy metals, we have found that anionic properties in wastewater can be reduced by using iron-type chelate resins containing iron iminopropionate and/or iron iminodipropionate as chelate-forming groups. The inventors have discovered that treatment of heavy metals has a remarkable removal effect and can almost completely adsorb and remove these heavy metals.

To explain the present invention in more detail, the chelate-forming groups used in the present invention include iminopropionate iron base and/or
Alternatively, the chelate resin having an iminodipropionic acid iron base is an H type, Li type, Na type, which has an iminopropionic acid group (CII) and/or an iminodipropionic acid group (CID) shown below as a chelate forming group. K
It can be easily obtained by reacting a chelate resin such as type, Ca type, or Mg type with an iron ion solution.

Examples of iron ion solutions include ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, ferrous bromide, and ferric bromide. can be used.

Further, as the base resin for these chelate resins, phenol resin, epoxy resin, urethane resin, melamine resin, vinyl chloride resin, styrene-divinylbenzene copolymer resin, etc. can be used.

(However, R is H, Li, Na, Ca/2゜M
In addition, the anionic heavy metals adsorbed and removed by the iron plate chelate resin described above can be easily eluted (recovered) by using a regenerating agent such as caustic soda, common salt, hydrochloric acid, nitric acid, or sulfuric acid. Another major feature is that the recycled resin can be used repeatedly.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Iminopropionic acid type chelate resin manufactured by Miyoshi Oil (
Product name: [Eporus MX-8J resin base is Na salt type having iminopropionic acid and iminodipropionic acid groups as epoxy resin] 100 hemp was added to 500 rrLl of 0.1% ferric chloride aqueous solution, and after stirring for 5 hours. The resin was thoroughly washed with water to obtain an iron (III) type chelate resin.

A column (diameter 15 mm) was filled with 10 Inl each of the Na type and iron (III) type chelate resin, and 100 p- of chromic acid aqueous solution (PH3) SV3 was used as hexavalent chromium.
0, the liquid was passed in a down flow manner.

The effluent was dispersed into 20 groups using a fraction collector, and the concentration of residual hexavalent chromium ions in the effluent was measured by atomic absorption spectrophotometry.

As a comparative example, a commercially available strongly basic ion exchange resin was also passed through in the same manner.

Figure 1 shows the results of these liquid passages. As is clear from Figure 1, the Na-type chelate resin before reacting with the iron ion solution hardly adsorbs hexavalent chromium.
Iron ([1) type chelate resin has a larger adsorption amount than commercially available strong basic ion exchange resins, and the lower limit of removal is 0.11]
Can remove hexavalent chromium below In, o, i ppm
The amount of hexavalent chromium adsorbed up to 47g/l-R is 63p.
The amount of adsorption until pHL leaks is 51.0 g/l-
It was R, wet.

Example 2 The results of passing arsenic (III) and arsenic (V) through the iron (III) type chelate resin obtained in Example 1 are shown.

The liquid passing conditions were the same as in Example 1.

Note that the concentrations of arsenic (III) and arsenic (V) were each 1100 pp, and aqueous solutions with a pH of 8.0 were passed through the tube.

The results are shown in Figure 2. Example 3 Using 6 times the amount of the iron (III) type chelate resin that adsorbed hexavalent chromium in Example 1 and filling it with 5% caustic soda aqueous solution as a regenerant, SV2, The hexavalent chromium was eluted by passing the solution in a down flow manner.

The amount of hexavalent chromium recovered in the eluent was 50.29/1
-R, wet, the recovery rate was over 98.4%.

Example 4 A 500ml beaker was charged with 25% sodium ethylenediamine dipropionate, 15g of redulucin, 40g of 37% formalin, and 300g of water, and heated at 50°C for 30 minutes.
After stirring for 0 minutes, the aqueous prepolymer solution was formed into a film, and heated at 130 to 150°C for 10 hours to obtain a cured resin.

The obtained cured resin was pulverized into 10 to 48 meshes.

50 g of the thus obtained lO~48 mesh iminopropionate sodium salt type chelate resin was
It was added to 500 rnl of an i% ferric nitrate aqueous solution and reacted for 30 minutes, and the obtained iron (III) type chelate resin was thoroughly washed with water and subjected to a liquid passage test.

Under the same liquid passing conditions as in Example 1, the liquid passing rate (l/l-R,
wet) was 520 times.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are explanatory diagrams showing the adsorption performance of heavy metals.

Claims (1)

[Claims] 1 Iminopropionic acid group ((1
)) and/or iminodipropionic acid groups ((II
)) is present as an anion in the solution using an iron plate chelate resin having iminopropionate iron base and/or iminodipropionate iron base as a chelate forming group obtained by reacting an iron ion solution with a chelate resin having iron ion solution. A method for removing heavy metals, characterized by adsorbing and removing heavy metals. (However, R is H, Li, Na, Ca/2゜M
g/2)