JPS5853957B2 - Treatment method for wastewater containing phenols - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing and/or recovering phenols from wastewater containing phenols.

Phenols are generally useful as industrial raw materials, and are widely used as raw materials for various medicines and agricultural chemicals, or as raw materials for producing polymeric materials.

However, these phenols are highly toxic to animals, animals, and fish, and the phenols contained in wastewater cause environmental pollution, so their emission standards and environmental standards are strictly regulated.

The purpose of the present invention is to separate phenols contained in wastewater to prevent environmental pollution, and to effectively recover the separated phenols and utilize resources effectively.

Activated sludge method, ozone oxidation method, activated carbon adsorption method, ion exchange resin method, liquid-liquid extraction method, etc. are conventionally known methods for removing phenols from phenol-containing wastewater.Industrially, activated sludge method is used. A relatively large number of ka-mori are used.

However, the activated sludge method requires a large capital investment and the phenol concentration in the wastewater is 1. It has drawbacks such as the need to strictly control the H1 temperature, etc.

There have also been reports of methods for adsorbing and removing phenols contained in wastewater using ion-exchange resins, but in all cases, the resin is regenerated using ion-exchange methods using alkaline solutions or solvents such as methanol. A cleaning method is used.

These regeneration methods have drawbacks such as being complicated in operation and requiring a large amount of organic solvent, and require a large amount of cost to remove and/or recover phenols from wastewater.

Other methods also have drawbacks such as inability to recover phenols, low phenol removal efficiency, and high cost for phenol separation.

The present inventors have conducted intensive research on a method for removing and/or recovering phenols from wastewater containing phenols, and have arrived at the present invention.

That is, the present invention brings phenols-containing wastewater into contact with a polyvinylpyridine resin (hereinafter referred to as PVP resin) to adsorb phenols onto the PVP resin.
The inventors have now discovered that by heat-treating the PVP resin that has adsorbed phenols, it is possible to recover the phenols and regenerate the resin.

The PVP resin used in the present invention refers to a crosslinked polymer of 2,3- or 4-vinylpyridine or a substituted derivative thereof.

Divinylbenzene is preferably used as the crosslinking agent.

A particularly preferably used PVP resin is a crosslinked polymer of 4-vinylpyridine, and among these, a macroporous type polymer shows excellent performance.

According to the present invention, there is no restriction on the method of contacting the phenol-containing wastewater with the PVP resin.

That is, the phenol-containing wastewater may be passed through a column filled with PVP resin, or the phenol-containing wastewater and the PVP resin may be brought into contact by stirring and mixing in a suitable container.

Examples of phenols that can be selectively adsorbed and removed from wastewater by PVP resin include phenol, cresol,
Examples include ethylphenol, resorcinol, hydroquinone, and derivatives thereof.

According to the present invention, there is no problem even if the wastewater that is brought into contact with the PVP resin contains various compounds other than phenols.

However, since free organic acids and inorganic acids or bases reduce the phenol adsorption activity of the PVP resin, it is desirable to neutralize the wastewater before contacting it with the PVP resin.

Industrial wastewater containing phenols is generated, for example, from chemical plants that produce oxygen-containing compounds by oxidizing hydrocarbons, chemical manufacturing plants, synthetic resin manufacturing plants, steel factories, and other process industrial equipment. The phenol recovery method can be used for any wastewater.

Further, the method for removing phenols from wastewater according to the present invention can sufficiently exhibit its phenol removal effect even when used alone, but it may be used in combination with other removal methods depending on the case.

Next, a method for reactivating the PVP resin by heat-treating the PVP resin that has adsorbed phenols to desorb the phenols will be described.

According to the present invention, phenols are easily desorbed from the PVP resin by heat-treating the PVP resin that has adsorbed phenols.

The heating temperature is preferably 80 to 200°C.

At temperatures below 80°C, phenols are not sufficiently desorbed from the PVP resin, and the phenol adsorption activity of the PVP resin is not fully recovered.

Furthermore, high temperatures of 200'C or higher are undesirable because the PVP resin deteriorates.

In addition, when heat treatment is performed, the desorption rate of phenols is increased by operating under reduced pressure conditions or passing gas such as air or nitrogen, and these methods are one of the preferred operating methods for the heat treatment method of the present invention. be.

A more desirable heat treatment method of the present invention is a method in which phenols are desorbed from the PVP resin by passing hot water or steam through the resin.

The amount of steam required to regenerate the PVP resin varies depending on the temperature of the steam and the type of phenol, but is generally 0.1 kg to 10 kg per resin 11.

The steam passed over the PVP resin is fully or partially condensed and subjected to post-treatment.

Generally, phenols have a lower vapor pressure than water, so the partially condensed liquid contains a high concentration of phenols, and it is easy to recover the phenols from this.

The steam from which phenols have been removed in this manner can be reheated if necessary and reused for regenerating PVP resin.

In addition, PVP resin that has desorbed phenols by passing through steam has recovered its phenol adsorption activity without losing its shape, and by repeating these operations, PVP resin can be used repeatedly. Become.

The method of the present invention will be explained below with reference to examples, but the scope of the present invention is not limited by these examples.

Examples 1 to 4 A glass column with an inner diameter of 201111 L was filled with 50 g of polyvinylpyridine resin (trade name Sumikire-hcR-2).

Water containing a certain concentration of phenol is poured into the top of this column.
When the column was run at a flow rate of 0.00 g/hr and the phenol concentration at the outlet of the column was measured, the results shown in Table 1 were obtained.

Comparative Example 1 A phenol removal experiment was conducted under the same conditions as in Example 2 using activated carbon instead of polyvinylpyridine resin.

The results are shown in Table-1. Table 1 Example 5 After long-term operation under the same conditions as in Example 1, the phenol concentration in the treated water reached 500 ppm (8
After 0 hours), the supply of phenol-containing water was stopped.

Next, keep the glass column warm and apply pressure from the bottom of the column for 12 hours.
The vapor coming out from the top of the column was cooled and condensed by passing 0°C steam.

The amount of condensed liquid was 100 g, and its phenol content was 8.2% by weight.

Next, after completing the steam treatment, a phenol removal experiment was conducted again under the same conditions as in Example 1, and the phenol concentration in the treated water was measured, and the results shown in Table 2 were obtained.

Table 2 The phenol concentration values in the treated water of Examples 1 to 5 and Comparative Example 1 are all values 2 hours after the start of operation.

Claims (1)

[Scope of Claims] 1. Phenols characterized by bringing phenol-containing wastewater into contact with a polyvinylpyridine resin to adsorb the phenols to the resin, and then desorbing the phenols by heating the resin. A method for removing and/or recovering phenols from wastewater containing phenols. 2. The method according to claim 1, wherein hot water or steam is passed when desorbing phenols by heating the polyvinylpyridine resin.