JPS60261590A - Treatment of waste water containing chlorinated hydrocarbon - Google Patents

Abstract

PURPOSE:To remove efficiently chlorinated hydrocarbons by treating waste water contg. chlorinated hydrocarbons in the coexistence with peroxides and compds. of group VIII elements on the periodic table. CONSTITUTION:Waste water contg. trichloroethylene, tetrachlorethylene, etc. is treated in the coexistence with peroxides such as hydrogen peroxide and the compds. of group VIII elements on the periodic table such as ferrous sulfate, ferrous chloride, etc. Consequently, the chlorinated hydrocarbons in the waste can be efficiently removed, and the concn. is reduced to about 5-14ppb.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for treating wastewater containing chlorinated hydrocarbons.

While the conventional aids and inventions are trying to overcome this problem, lazily chlorinated hydrocarbons are used in a wide range of fields as cleaning agents, extractants, diluents, reaction solvents, etc., especially in the field of metal degreasing and cleaning. Although they are used in large quantities, the problem of processing wastewater containing such chlorinated hydrocarbons has come to be understood as a pollution problem, and is strictly regulated from the standpoint of environmental conservation and health and hygiene.

Conventional methods for removing chlorinated hydrocarbons contained in wastewater include aeration methods and activated carbon adsorption methods, but both methods require huge capital investment, and the former in particular causes air pollution. However, the latter method not only requires a large amount of relatively expensive activated carbon, but also has problems in its recycling process.

The present invention overcomes these drawbacks by a simple method at low cost, and eliminates chlorinated hydrocarbons contained in wastewater, such as trichlorethylene, tetrachlorethylene, 1,1
．． The present invention provides a method for efficiently removing 1-trichloroethane and the like.

A means for solving the problem, that is, the gist of the present invention is to treat wastewater containing chlorinated hydrocarbons in the coexistence of peroxide and a compound of a group 8 element of the periodic table (hereinafter simply referred to as a metal compound). A method for treating wastewater containing chlorinated hydrocarbons is provided.

Hydrogen peroxide is generally used as the peroxide in the present invention.

Further, preferable metal compounds used in the present invention include:
Examples include iron compounds such as ferrous sulfate, ferric sulfate, ferrous chloride, and ferric chloride.

The amount of peroxides and metal compounds used depends on the type of these treatment agents, the type and amount of chlorinated hydrocarbons contained in the wastewater,
It may be selected as appropriate depending on the properties of the wastewater, etc., and is not particularly limited, but for example, usually chlorinated hydrocarbon
per liter of wastewater containing 0.00 ppm peroxide.
Use 1 to 30 mol, and 0.1 to 30 mol for metal oxide.

The processing temperature is typically 40 to 50°C, but is not limited thereto.

The processing operation may be carried out by a static method, or the processing efficiency can be increased by stirring.

The concentration of chlorinated carbon hydrogen in wastewater treated by the method of the present invention is about 3 to 14 ppb, which poses no problem in terms of environmental protection.

Since treated wastewater is usually acidic, it is treated with alkali, filtered, and then either drained or reused.

In addition, TOC, COD, B of the wastewater subjected to the above treatment
In order to adjust the OD and the like, the treated wastewater may be further treated with a flocculant, if desired.

Suitable flocculants used for this purpose include JP-A No. 5
An example is the precipitation dispersing agent for water treatment disclosed in Japanese Patent No. 8-216705.

Through such flocculant treatment, wastewater TOC, COD,
and BOD are, for example, about 5-2S and about 5-2S, respectively.
20, and can be adjusted to about 5-10.

Hereinafter, the present invention will be explained by examples.

Example 35 to 100 ml of raw water containing 78 ppm of trichlorethylene
21 ml of %H2O and 1 ml of 10% ferric sulfate aqueous solution
was added and treated at about 45°C for about 60 minutes (pH 2),
It was neutralized using an aqueous sodium hydroxide solution and subjected to filtration treatment, and the concentration of trichlorethylene in the filtrate was measured according to method No. 15 of Kansei Water, Environmental Sanitation Bureau, Ministry of Health and Welfare.
It was ppb.

When this treatment solution was further treated using a flocculant (Saburo CD manufactured by Murata Sangyo Co., Ltd.), the concentration of trichlorethylene was 14 ppm and the COD was 21 ppm.

Example 2 When 100 ml of raw water containing 520 ppm of trichlorethylene was treated with H2O2 and ferric sulfate according to Example 1, the concentration of trichlorethylene was 10 ppb.

Effects of the Invention By the method of the present invention, chlorinated hydrocarbons in wastewater are efficiently removed and their concentration is reduced to about 5-14 ppb.

Claims (1)

[Claims] 1. Treating chlorinated hydrocarbon-containing wastewater with peroxide and No. 8 of the periodic table.
A method for treating wastewater containing chlorinated hydrocarbons, characterized in that the treatment is carried out in the coexistence of a group element compound. 2. The method according to item 1, wherein the treated wastewater is further treated with a flocculant, if desired.