JPS6111118A - Filter medium for heavy metal - Google Patents

Abstract

PURPOSE:To obtain extremely good filtration effect for waste liquid contg. heavy metals by using a flter medium prepd. by compression molding, water permeable mineral, Portland cement and basic hardening agent added with water. CONSTITUTION:The mixture of an inorg. basic hardening agent and water is added to a mixture consisting of dry shirasu particles having 0.5-1mm. particle size and Portland cement. The mixture is stirred, compression molded in a molding flask and dried. A filter medium 2 obtd. above is fitted to a waste water discharging port 1' provided to the bottom of a tank 1 so as to block the discharging pipe, and aq. soln. 3 of heavy metal is charged from the top of the tank 1 to filter the heavy metal. When plating waste liquid contg. 389mg/l total Cr and 340mg/l hexavalent Cr is filtered using the filter medium having 50mm. thickness, contents of total Cr and hexavalent Cr in the treated liquid are 0.08mg/l and 0.06mg/l, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Purpose of the Invention 1) Industrial Field of Application The present invention relates to heavy metal filter media, particularly those containing harmful heavy metals such as chromium, cadmium, lead, arsenic, and mercury. This article relates to a filter material for ion exchange filtration of industrial waste. 1
2) Conventional technology In a factory that uses heavy metals, when disposing of a used plating solution, it is stored in a filtration tank and subjected to sedimentation filtration.

In addition, the treatment of various heavy metals (: means the characteristics of the heavy metals (=
The appropriate treatment method (for example, precipitation filtration method or reduction neutralization method, etc.) (secondarily, the treatment involves multiple steps and is then drained.

3) Problems to be solved by the invention However, the conventional treatment method C2 required a large amount of equipment (;, necessitated a large investment in equipment. In addition, heavy metals with different characteristics There was a need for a treatment method suited to the characteristics of each material.Furthermore, even if existing equipment was used, no effective and satisfactory filtration material for heavy metal treatment C2 could be found, and in the industry, an effective and simple method has not been found. A filter material made of heavy metals, which also requires a small amount of capital, has been awaited.

Composition of the invention 1) Means to solve the problem As a means to solve the above problems.

A mixture of a water-permeable mineral and Portland cement mixed and stirred, an appropriate hardening agent and water mixed and stirred was compacted or compressed in a mold, and cured to form a heavy metal filter medium. (=Specifically, it was a heavy metal filter material using Shirasu as a water-permeable mineral.

2) Effect When industrial waste liquid containing one heavy metal is filtered using the filtering medium according to the above-mentioned method, an extremely good filtration effect can be obtained.

3) Example The filter medium is manufactured as shown below.

Dried whitebait particles (0.5 plate to 1 mm) and Portland cement are blended and stirred to form a blend. Next, an inorganic salt hardening agent and water are mixed and stirred to form an additive. Subsequently, the formulation and additives are mixed and stirred. Further, the mixture is placed in a pre-prepared mold of a certain shape, compacted or compressed to form a predetermined shape, and cured until the mold is solidified.Finally, the mold is removed from the mold. Take it out and let it dry naturally in the air.

Dry with steam or heat.

An example of the filter material manufactured by the above process will be explained based on one drawing, but the shape of the filter material is as shown in Example C below: it can be shaped to suit various uses without being restricted. Of course. FIG. 1 is a sectional view showing a single heavy metal filtration device. This device consists of a tank 1 with a drain port 1' at the bottom (2. Lower part C in the tank; a filter material 2 is installed inside the C Mita frustum to block the drain port 1', and a heavy metal aqueous solution 3 is poured from above the tank. It is a device for filtering out heavy metals, and a conduit (not shown) is connected to the discharge port 1' for drainage. Fig. 2 is a cross-sectional view showing an agricultural waterway.

In conventional construction, irrigation canals are formed in the ground with concrete, but agricultural water is contaminated by wastewater runoff from factories and penetrates the concrete.

This caused contamination of soil or farmland.

In the embodiment, an irrigation channel is formed using a filter material 5 instead of the ground 8 concrete. Figure 3 is a cross-sectional view of the ground. If the soil contains harmful substances, the filter material 6 should be buried at the boundary between the harmful soil 7 and the non-hazardous soil 8 (2) to prevent the diffusion of harmful substances. 9 is a ground layer formed by pouring concrete milk.Furthermore, if a filter material 10 is laid on the foundation and embankment 11 is performed, it can be used as a reclaimed land.In addition, the filter material 6 is buried. In such a case, after digging the soil, it may be sequentially bundled and cultured while being filled with the mixture.

Although not shown, the ground was excavated.

The bottom and walls surrounding it on all sides are made of filtration material, and can also be used as a treatment facility to dispose of harmful substance deposits.

Furthermore (= sewage treatment, mine rainwater treatment (both are effective (two functions, filtering harmful substances).

3 Effects of the Invention To explain the experimental results in which plating waste liquid was filtered using the filter material according to the present invention, when plating waste liquid was put into the filtration device based on Fig. 1 and a filter material with a thickness of 50 myn was used, As a result of measurement using the JIS standard (two-layer detection method), before treatment, the total chromium value was 389 mg/l, and the hexavalent chromium value was 340.
After treatment, C2 contained 0.08 mg/l of total chromium and 0.06 mg/l of hexavalent chromium.
It became the value of j.

Similarly, the results of experiments with heavy metals such as cadmium, lead, arsenic, copper, and mercury showed that the filter material based on the present invention can filter all heavy metals in common, and can obtain good filtration results. Ta.

As explained above, the filter material according to the present invention can greatly reduce the concentration of heavy metals, so it can be used for filtering various heavy metals.

It can be used for agricultural waterways, mine rainwater treatment, sewage treatment, and for preventing the spread of heavy metals in soil containing heavy metals. Also,
This simplifies the filtration equipment and significantly reduces equipment investment.

Note that even when volcanic ash containing volcanic glass was used as the whitebait of the present invention, similar effects were obtained.

[Brief explanation of drawings]

Each figure shows one embodiment of the present invention. FIG. 1 is a sectional view of a heavy metal filtration device, FIG. 2 is a cross-sectional view of an agricultural waterway, and FIG. 3 is a sectional view of the ground. 1...Tank 1'...Drain port 2.5,
6.10...Filtering material

Claims (2)

[Claims] (1) A heavy metal filter material made by mixing and stirring a mixture of water-permeable minerals and cement with an appropriate hardening agent and water, compacting or compressing the mixture in a mold, and curing it. (2) The heavy metal filter material according to claim 1, wherein the water-permeable mineral is shirasu.