JP2012220487A - Water purification apparatus improving radioactive substance removal performance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water purification apparatus capable of improving a removal ratio of radioactive substance in addition to a removal performance using a reverse osmosis membrane since, in a generally spread water purifier using a reverse osmosis membrane, most of various substances contained in a liquid can be removed to a concentration meeting a drinking water quality criterion or lower, but perfect removal is disabled in accordance with various conditions such as a removal target substance, liquid temperature, pressure, osmosis membrane type and the like, in the case of radioactive substance, even if a reverse osmosis membrane is used, the radioactive substance is made residual in approximately 2 to 5% and, in particular, regarding radioactive iodine 131, if it is residual in drinking water even a little, it may be accumulated in the thyroid of infant or child, thereby increasing risk in health such as thyroid cancer.SOLUTION: As preprocessing of a reverse osmosis membrane filter, an active carbon filter is disposed and as post-processing of filtrate of the reverse osmosis membrane filter, a filter is disposed which removes radioactive substances through chemical reaction of silver ion with respect to the radioactive substances and water is purified, thereby improving a removal ratio of radioactive substances.

Description

  The present invention relates to a water purifier having a radioactive substance removing performance.

  Water purification equipment that uses reverse osmosis membranes among water purification technologies that are already in widespread use can remove various substances contained in the liquid to a concentration that conforms to the drinking water quality standards, including radioactive iodine and radioactive cesium contained in raw water The radioactive material can also be removed.

  However, 100% removal cannot be performed depending on various conditions such as the substance to be removed, concentration, liquid temperature, pressure, and type of osmotic membrane. It is known that a residue of about 5% occurs.

As shown above, even when a reverse osmosis membrane having excellent microfiltration performance is used, a residual concentration of several percent is generated in purified water, and in particular, in the case of radioactive iodine 131, even a minute amount remains in drinking water. The purpose of the present invention is to obtain a water purifier having a complete removal performance of radioactive iodine 131 in the present invention, because it accumulates in the thyroid gland of infants and children and causes internal exposure, resulting in high risk of causing cancer and leukemia. To do.

    By using a reverse osmosis membrane, approximately 95% to 98% of the radioactive substances contained in the raw water to be purified can be removed. In addition, an activated carbon filter is used as a pretreatment for the reverse osmosis membrane filter. As a post-treatment of water that has been placed and filtered through a reverse osmosis membrane filter, a radioactive substance is removed by placing a filter that removes the radioactive substance by a chemical reaction with silver ions and radioactive substances (mainly radioactive iodine) and purifying the water. The removal rate can be increased.

  As described above, 98% or more of radioactive cesium 137 can be obtained by combining a water purification method using a reverse osmosis membrane, which is commonly used in a water purification apparatus according to the present invention, and a filter that removes radioactive substances (radioactive iodine 131). In particular, radioactive iodine 131 that causes serious health damage due to accumulation in the thyroid gland can be completely removed.

  Connection example diagram of each filter according to the present invention

  Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  In FIG. 1, raw water 1 is sucked into a pressurizing pump 2, pressurized to about 0.5 to 0.7 MPs, and flows into the activated carbon filter 3. The pressure pump 2 may be inserted between the activated carbon filter 3 and the reverse osmosis membrane filter 4. When the raw water 1 passes through the activated carbon layer in the activated carbon filter 3, organic substances, chlorine and the like that wear the reverse osmosis membrane filter 4 and the radioactive substance removal filter 4 are adsorbed and removed, and then flows into the reverse osmosis membrane filter 4.

  About 95% to 98% of the substances contained in the pretreated water flowing into the reverse osmosis membrane filter 4 from the activated carbon filter 3 cannot pass through the osmosis membrane and are discharged out of the water purification system as waste water 6. Is done. The drainage ratio at this time can be adjusted by the drainage adjustment valve 5.

  The water filtered through the reverse osmosis membrane filter 4 still contains about 2% to 5% of radioactive material remaining. Then, it is made to flow into the radioactive substance removal filter 7 continuously. The radioactive substance removal filter 7 is filled with an adsorbent 8 on which silver is deposited. Here, the radioactive iodine 131 remaining in the water undergoes a silver iodide reaction with iodine ions and silver ions to form silver iodide and is fixed to the adsorbent 8.

  By the above, the purified water 9 which has been purified by completely removing the radioactive iodine 131 from the remaining radioactive substance can be obtained.

  Since the present invention can obtain a high removal rate for harmful substances contained in liquids such as drinking water, especially radioactive substances that are of concern for health damage, it is released into the environment due to nuclear reactor accidents, etc. Even if the radioactive material is infiltrated underground and contaminates well water or enters water purification plants via river systems such as rivers and lakes, drinking water can be secured with peace of mind.

DESCRIPTION OF SYMBOLS 1 ... Raw water 2 ... Pressure pump 3 ... Activated carbon filter 4 ... Reverse osmosis membrane filter 5 ... Drainage adjustment valve 6 ... Drainage 7 ... Radioactive substance removal filter 8 ... Adsorbent 9 ... purified water

Claims (2)

  A water purifier comprising: an activated carbon filter, a reverse osmosis membrane filter, and a filter that removes a radioactive substance by a chemical reaction of silver ions to the radioactive substance in order to increase a removal rate of the radioactive substance contained in the liquid.   An activated carbon filter is disposed as a pretreatment of the reverse osmosis membrane filter, and a filter that removes the radioactive substance by a chemical reaction with respect to the radioactive substance of silver ions is disposed as a post-treatment of the filtrate of the reverse osmosis membrane filter. The water purifier according to claim 1.

Images