JPS6249914A - Treatment of oil-contaminated water - Google Patents

Abstract

PURPOSE:To effectively remove the oil from the titled oil-contaminated water by adding a specified substance to the contaminated water contg. emulsified oil. CONSTITUTION:Oil absorptive or oil adsorptive rubber consisting of styrene- butadiene rubber, etc., activated carbon, and an inorg. adsorbent or an inorg. porous substance (hereinafter referred to as inorg. mineral matter) are added to contaminated water contg. emulsified oil. Vermiculite, diatomaceous earth, etc., can be exemplified as the inorg. mineral matter. The grain size of the oil absorptive (adsorptive) rubber powder is preferably regulated to <=1mm and the grain diameter of the activated carbon or the inorg. mineral matter is controlled to 0.1-5mm. The mixing ratio of the oil absorptive (adsorptive) rubber powder to the activated carbon or the inorg. mineral matter is preferably adjusted to 1/1-1/10. Consequently, oil is separated from the contaminated water in a short contact time with an excellent demulsifying characteristic and a high oil removal rate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a treatment method for adsorbing and removing oil from emulsion-stabilized oil-water mixtures such as various oil-water mixtures, urban sewage, Ichigata wastewater, etc.

Conventional techniques and their problemsAs a method for treating oil-containing wastewater containing emulsion-stabilized oil,
There is a method of adding a large amount of aluminum sulfate or iron salts to destroy the emulsified oil and precipitate it to separate it, but this requires a large-scale equipment and the treatment of the separated product is cumbersome, so the adsorption removal method using an adsorbent has attracted attention. Various types of adsorbents have been proposed.For example, Japanese Patent Application Laid-open No. 52-91791 proposes an article in which a molded article made of fiber material is immersed in a polymer emulsion and then an iron-based compound pipe is attached. has been done. However, although it is thought that this material destroys emulsification with an iron-based compound and adsorbs the oil produced by destroying the emulsification into the a-substance material, it has the drawback that the oil adsorption equivalent of the fiber m material is not sufficient.

On the other hand, oil-absorbing rubber powder has a high ability to adsorb oil, especially petroleum-based oil, but its ability to adsorb emulsified oil is extremely inferior to that in a non-emulsified state.

Means to Solve the Problem The present inventors discovered that in order to properly treat oil-contaminated water, it is necessary to adsorb and remove oil in a state that destroys the emulsified state.1. As a result of repeated studies, we found that at least 11 combinations were selected from oil-absorbing or oil-absorbing rubber powder, activated carbon, inorganic adsorbent, or inorganic porous material! The present invention was completed based on the discovery that the combination with 1 exhibits excellent adsorption ability for emulsified oil.

The method for treating oil-contaminated water according to the present invention includes adding an oil-absorbing or oil-absorbing rubber and at least one selected from activated carbon, an inorganic adsorbent, or an inorganic porous material to emulsified oil-containing polluted water. This method is characterized by removing oil that has been emulsified.

Examples of oil-absorbing or oil-absorbing rubbers include styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, butyl rubber, and isoprene rubber.

Examples include natural rubber and norbornene rubber, and norbornene rubber obtained by ring-opening polymerization of norbornene is preferably used because it has excellent oil absorption or adsorption properties.

Further, as the activated carbon, ordinary activated carbon for adsorption is used, and as the inorganic adsorbent or inorganic porous material (hereinafter referred to as inorganic mineral material), vermiculite is used.

Examples include diatomaceous earth, activated clay, perlite, talc, bentonite, mica, and shirasu balloon.

Next, as an oil-absorbing or oil-absorbing rubber powder, the particle size is 1
In particular, an average particle diameter of about .alpha.3 to .alpha.8 is preferable from the viewpoint of oil adsorption ability and ease of handling, and the particle diameter of the activated carbon or inorganic mineral substance is preferably in the range of 0.1 to 5 fI#I. If the powder rubber is less than 01, it tends to form blocks when it adsorbs oil, resulting in poor adsorption ability, and if it is more than 5, the particle size is large and cannot be mixed uniformly with the rubber powder, resulting in uneven distribution. .

The mixing ratio of the oil-absorbing rubber powder and the activated carbon or inorganic mineral substance (hereinafter, both simply referred to as the mixture) is a weight ratio of rubber powder:mixture of 1=1 to 1:10. A range of 1 or less is preferable, and if the mixture is less than 1, the effect of removing emulsified oil will be poor, and if it is more than 10, the oil adsorption effect will be reduced, which is not preferable.

Effect In the present invention, this is due to an excellent synergistic effect on the emulsified oil that was not observed with the rubber powder or the mixture alone, respectively.The mechanism of this synergistic effect is not clear, but it is probably due to the emulsification of the mixture with the emulsified oil. The rubber powder and the mixture agent exhibit excellent adsorption action on the oil droplets, and the mixture agent particles intervene between the rubber particles to prevent block formation and ensure a flow path for the treated water. considered to be a thing.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1.2 and Comparative Examples 1 to 3 Kerosene was added to water as raw water to be treated, a nonionic surfactant was added thereto, and the mixture was sufficiently stirred to prepare emulsified raw water. The oil in the raw water was completely emulsified, and no floating oil was observed.

The water quality (oil content) of raw water and treated water was measured by the normal hexane extract method specified by JIS method.

Norbornene rubber powder was used as the oil-absorbing rubber powder, and perlite was selected as the activated carbon and inorganic mineral adsorbent.The average particle size of the norbornene rubber powder was α3.
Simple, the average particle size of activated carbon is 07, and that of pearlite is 0.
．． It was 6 friends.

Norbornene rubber and activated carbon or pearlite were added so that the ratio by weight was 1=2, and thoroughly mixed to prepare a homogeneous mixture. Spread this mixture between 30 mm in inner diameter and 30 mm in height.
A packed tower with 150 liters of water is filled, raw water is allowed to flow down from above, treated water is discharged from below, and the space velocity (Spac
e Velocity, S.

The flow rate was regulated so that 2.0 (1/hrl) was obtained.For comparison, the norbornene-based rubber powder was dispersed and adhered to the valve material (comparative example). 1], a polypropylene nonwoven fabric with norbornene rubber dispersed in it (Comparative Example 2), and a commercially available fiber-based adsorbent (trade name Palcross) (Comparative Example 3) were filled and tested.The results are as follows: Shown in the table.

In addition, in Comparative Examples 1 to 3, turbidity remained in the treated water, and in Example 1
In Example 2, the turbidity of the treated water was extremely low, and in Example 2, no turbidity was observed in the treated water, and the removal rate was also extremely excellent.

Note to Table 1: Space velocity WE (S, V-5=2.0 (1/h
rl raw water quality: 200 ppm Examples 3 to 6 In the same manner as in Example 1, 300 ppm raw water for treatment was
Using the same norbornene-based rubber/perlite mixture as that prepared and used in Example 1, an experiment was conducted by changing the space velocity in the packed column. The results are shown in Table 2.

Table 2 As shown in Table 2, when the space velocity is increased, that is, S, V, 1! Even when the contact time was extremely short (>0), emulsion destruction and oil adsorption were sufficiently carried out, and the quality of the treated water was below the target value of 15 ppm, indicating a high oil removal system. In addition, the above Example 3
-6, the treated water (no turbidity was observed).

Effects of the Invention According to the present invention, as shown in the above examples, excellent emulsion breaking properties and a high oil removal rate are exhibited, and furthermore, this effect is exhibited even when the contact time is short, and the oil absorption of the oil-absorbing rubber is improved. Ability is effectively demonstrated. As for raw water quality treatment range, it has excellent emulsion breaking and oil removal rates over a wide range of oil content from 800 ppm to 20 ppm, and is superior to emulsions stabilized with nonionic surfactants that are difficult to treat as shown in the above examples. It has excellent emulsion breaking properties, and is extremely effective as a method for treating emulsified oil-containing wastewater such as urban sewage and industrial wastewater.

Claims (1)

[Claims] 1. Adding an oil-absorbing or oil-absorbing rubber and at least one selected from activated carbon, an inorganic adsorbent, or an inorganic porous substance to polluted water containing emulsified oil to remove the emulsified oil. A method for treating oil-contaminated water, characterized by: