JPH0135714B2 - - Google Patents

Description

[Detailed description of the invention]

Conventionally, natural pigments such as humic acid and fulvic acid in well water have been removed by adding large amounts of flocculants such as aluminum salts to lower the pH and have a flocculating effect. Removal of color from naturally colored water has been a challenge during water treatment due to the drawbacks of color generation and increased cost. This invention focuses on an operation in which iron and manganese dissolved in deep well water are removed as oxidized insoluble substances in the presence of an oxidizing agent such as chlorine using highly active manganese oxide as a catalyst. However, since electrolytic manganese dioxide has particularly excellent activity as a manganese catalyst, we investigated the possibility of applying this to the removal of color in humic substances, and the results were obtained. As is well known, the electrolytic manganese dioxide used in the method of this invention is produced by electrolyzing manganese sulfate or manganese chloride produced from manganese ore, and is made of highly pure γ-type manganese dioxide and does not contain bound water. It is a highly active compound. Next, the method of this invention will be explained in comparison with a conventional method using manganese sand in naturally colored water. The apparatus is mainly composed of a overcoat 1 as shown in the attached drawing, and if the chromaticity load is very high, ozone treatment may be performed, so an ozone reaction tower is installed before the overcoat 1. 2 is provided, but this is not relevant to the implementation data presented below. In the system 4 leading from the raw water tank 3 to the overtube 1, a pressurized air injection section 5, a NaClO addition section 6,
A coagulant adding section 7 is provided, and a contact catalyst agent 8 is loaded into the overtube 1 . The inner diameter of the above tube 1 is 100 mm, the agent height is 1500 cm,
As agent Electrolytic manganese dioxide Manganese sand Effective diameter 0.43mm 0.59mm Uniformity factor 1.40 1.60 Water flow conditions SV = 2l/Hh LV = 30m/Hh The test water (raw water) is humic acid colored water and contains a small amount of iron and manganese. However, the amount is not large enough to affect the chromaticity. First, add sodium hypochlorite to raw water as an oxidizing agent.
2ppm, polyaluminum chloride 5ppm as a coagulant
Add. Tables 1 and 2 compare the treatments using an electrolytic manganese dioxide catalyst agent and a conventional manganese sand agent. In addition, residual chlorine is 0.5 to 1.0 mg/
Made it exist.

【table】

[Table] In the above example, sodium hypochlorite is used as the oxidizing agent, but by using ozone as the oxidizing agent, there is no concern about trihalomethane formation, which is advantageous, or it is possible to increase dissolved oxygen in water. For this purpose, pressurized air injection may be performed. This invention is implemented as described above, but when compared with conventional flocculants, the amount of chemical injection is approximately 1/100, the amount of sludge is also less than 1/100, and the amount of dissolved iron, etc. As a matter of course, the effect of removing manganese is also excellent, making it an extremely effective method for treating naturally colored water.

[Brief explanation of drawings]

The accompanying drawing is a system diagram of an apparatus for carrying out the method of the invention. In the figure, 1...transfer cylinder, 2...ozone reaction tower, 3...raw water tank, 4...system line, 5...
Pressurized air introduction part, 6...NaClO addition part, 7...
Flocculant addition part, 8... contact catalyst agent.

Claims (1)

[Claims] 1. In a method for removing dissolved substances in water using highly active manganese oxide as a catalyst, electrolytic manganese dioxide particles are used as the manganese oxide, and the chromaticity of naturally colored water is removed using humic acid and fulvic acid. A method for removing chromaticity of water, which is characterized by: