Method for treating raw water containing hardly decomposable substance

Abstract

A method for treating a raw water containing a hardly decomposable substance, which comprises the following steps: a step (B) of adding an adsorbing agent to a raw water containing a hardly decomposable substance (a raw water to be treated) to allow said adsorbing agent to adsorb the hardly decomposable substance (an adsorption treatment step), a step (C) of separating a permeated liquid by the use of a filtration film, to concentrate the adsorbing agent having absorbed said hardly decomposable substance (a film filtration treatment step), and (D) a step of chemically decomposing the hardly decomposable substance being adsorbed in the concentrated adsorbing agent by a peroxide, without the operation for desorption from said adsorbing agent (a chemical decomposition step), and, by the above steps, concentrates hardly decomposable substances such as dioxins contained in a contaminated water (the raw water to be treated) and converts the hardly decomposable substances to harmless substances. The above method can be applied also to a raw water containing a reducing substance such as a hydrogensulfite for neutralizing free chlorine, the application thereof is not limited by the properties of hardly decomposable substances being contained, and also it allows conversion of hardly decomposable substances to harmless ones with good efficiency at a low cost.

Description

Technical field [0001] The present invention relates to a method for treating water containing hardly decomposable substances such as dioxenes and other endocrine disrupting substances. Background technique [0002] In 1999, Japan formulated a special treatment method for diene countermeasures. In this special treatment method for diene countermeasures, the emission standard of dienes is set to 10pg-TEQ / L or less. On the other hand, waste water from incinerator disintegration works, industrial waste water discharged from specific facilities, and a part of soil leaching water sometimes contain high concentrations of diolefins that significantly exceed this standard. Therefore, it is very hopeful that developments can be developed to reduce them. Treatment or removal technology. [0003] In addition, endocrine disrupting substances such as bisphenols (also called environmental hormones and endocrine disrupting chemicals) other than diolefins, and various organic chlorides represent...

AI Technical Summary

Problems solved by technology

[0022] However, as disclosed in the aforementioned JP-A-2003-93999 or JP-A-2003-285043, when a persulfate is added to a refractory organic compound to chemically decompose the compound, the refractory organic compound The decomposition efficiency is low, so it is extremely difficult for high concentrations

On the other hand, as a treatment method for such high-concentration refractory organic compounds, persulfate can also be used by adding metal salts such as ruthenium salts, but since such metal salts are very expensive, it is not practical in terms of cost.

[0023] In the technique disclosed in Japanese Patent Application Laid-Open No. 2003-144857, for drainage with little solids in the decomposition product, since the solid deposition film layer in the decomposition product will not be formed on the metal screen, the fine particle decomposition product containing dioxene Solids or dissolved dioxenes do not pass through the metal screen, sometimes rendering the treatment inadequate

[0024] For the technology disclosed in JP-P11-347591 and JP-2000-354894, when there is free chlorine in the polluted water, reducing substances such as excess bisulfite must be added for neutralization, Since such bisulfite and the like interfere with chemical decomposition, it cannot be said to be an effective method for separating and removing refractory substances.

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