Liquid purification or separation – Processes – Separating
Reexamination Certificate
1999-05-06
2001-06-05
Popovics, Robert J. (Department: 1723)
Liquid purification or separation
Processes
Separating
C210S770000, C210S780000, C210S386000, C210S387000, C100S037000, C100S116000, C100S121000, C100S15500G
Reexamination Certificate
active
06241900
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a waste water treatment method and apparatus for collecting sludge, oily substances, scum, and so on which exist in waste water, float and precipitate therein and for reducing the volume thereof by dehydrating them.
2. Description of the Related Art
Conventionally, waste water, which was discharged from kitchens, meat and marine product processing factories, oil manufacturing factories, oil and fat processing factories, repair shops, gas stations, and the like, included a large amount of wastes which contained animal oils and fats, vegetable oils and mineral oils, and wastes containing animal and vegetable oily substances which were made when various materials were processed.
Since these wastes must be previously removed from the waste water when the waste water is treated, they were conventionally separated and removed with nets, screen meshes and the like. However, when the waste water contains oily substances, they float in the waste water or on the surface thereof as grease-like lumps containing water and sludge or as scum-like lumps containing bubbles.
When the waste water is to be purified, it is an important theme to subject the waste water to biological treatment to permit a prescribed quantity of microorganisms to live in the waste water.
Microorganisms in water have a self-purifying capability. When, however, the amount of oxygen supplied into the water is smaller than the amount of oxygen consumed by them, aerobic microorganisms, which live by taking oxygen, will die because the amount of oxygen dissolved in water is reduced. When no oxygen exist in the water, anaerobic microorganisms, which take oxygen contained in organic matters, will breed and reduce and decompose the organic matters.
The biological treatment is classified into an aerobic treatment and an anaerobic treatment: in the aerobic treatment, oxygen contained in air is sufficiently supplied to polluted water by aeration and the like so that dirt is decomposed and purified; whereas, in the anaerobic treatment, air is prevented from being in contact with polluted water so that anaerobic organisms breed in the area where no oxygen exists and decompose and purify the dirt.
However, since the waste water from kitchens and the like contains a large amount of suspended oily substances, the waste water has a problem that oil sludge clings to a fluidized bed, that is, to the surfaces of carriers onto which microorganisms cling and chokes the microorganisms clinging onto the carriers when the biological treatment is performed.
Since the waste water containing the oily substances clogs nets, screen meshes and the like, the oily substances cannot be separated and removed. The animal oils and fats contained in waste water discharged from kitchens and the like are not solidified while they are at a high temperature. However, since they are solidified when cooled in such places as a raw water tank for treating waste water, a cesspool located at some midway point and a watercourse, the flow of the waste water is obstructed by the solidified animal oils and fats and cannot be treated well.
To remove scum and the like clinging to the tank and the like, there was conventionally employed a method of heating the portions of them which are liable to precipitate by steam or hot water piping. However, the scum and the like which contain sludge and residues, become creamy or sometimes contain bubbles have a problem that they cannot be removed even if they are heated as well as they are removed in only a limited amount even if a worker remove them with a rod or a ladle. Thus, there arises a problem that raw water tanks for treating waste water, cesspools located at some midway point and the like are made unusable.
SUMMARY OF THE INVENTION
To solve the above problems, a first object of the present invention is to provide a waste water treatment method and apparatus capable of obtaining treated water which can be subjected to a microbial treatment by at least collecting and removing oily substances floating in waste water.
A second object of the present invention is to provide a waste water treatment method and apparatus capable of maintaining a waste water treatment tank for storing and treating waste water and the like in a usable state for a long time by collecting and removing not only sludge precipitating in the waste water but also oily substances floating in the waste water.
The waste water treatment method of the present invention is characterized by comprising the steps of supplying waste water containing oily substances into a treatment tank and storing the waste water in the treatment tank; forming a stream to the waste water for causing the waste water to flow out of the treatment tank; feeding a permeable sheet into the treatment tank; causing the waste water, which flows downstream, to pass through the permeable sheet, while the permeable sheet travels in the treatment tank so as to traverse the surface of the waste water on a downstream side; and collecting the waste water having passed through the permeable sheet by causing precipitates and floating substances to cling onto the permeable sheet and gathering them by the permeable sheet.
According the above distinctive feature, the permeable sheet is fed into the treatment tank in which the stream is formed. The waste water, which flows downstream, is caused to pass through the permeable sheet, while the permeable sheet travels in the treatment tank toward the outside so as to traverse the surface of the waste water on the downstream side in the flowing direction of the waste water. Therefore, not only the sludge in the waste water but also the oily substances floating in the waste water can be collected and removed because they cling to the permeable sheet and are gathered by it. As a result, a waste water treatment tank and the like can be maintained in a usable state for a long time.
According to the waste water treatment method of the present invention, it is preferable that the permeable sheet is continuously or intermittently fed and collected.
With this arrangement, since the fresh surface of the permeable sheet is always fed, the clogging of the permeable sheet can be prevented and the clinging property of it can be improved.
According to the waste water treatment method of the present invention, it is preferable that the permeable sheet is moved while it is inclined obliquely upward with respect to the direction in which the waste water flows.
With this arrangement, since the area of the permeable sheet, onto which the substances floating on the surface of the waste water flowing downstream cling, is increased by the inclination of the permeable sheet, the filtrating effect of the permeable sheet can be improved.
According to the waste water treatment method of the present invention, it is preferable that the permeable sheet is pressed after precipitates and floating substances cling onto the permeable sheet.
With this operation, since the water contained in the permeable sheet is removed by pressing the permeable sheet, the weight of the permeable sheet can be reduced as well as the permeable sheet can be easily destroyed by fire in the next process.
According to the waste water treatment method of the present invention, it is preferable that the permeable sheet is pressed by a press means after it is folded to two strip-shaped sections by a guide means while it is moved.
With this arrangement, since the permeable sheet is folded to the two sections, the fluid oily substances, sludge and the like which cling to the permeable sheet can be continuously pressed without removing from the permeable sheet.
According to the waste water treatment method of the present invention, it is preferable that the permeable sheet having been pressed is destroyed by fire in the state it is wound to a roll shape or in the state as it is as a strip shape.
With this operation, since the permeable sheet is wound to the roll shape or formed to the strip shape, it can be made compact and easily
Fukuzuka Kunihiko
Nakamura Shin-ichi
Hayes, Soloway, Hennessey Grossman & Hage, P.C.
Omega Co. Ltd.
Popovics Robert J.
LandOfFree
Unrollable media filtration with subsequent folding and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Unrollable media filtration with subsequent folding and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Unrollable media filtration with subsequent folding and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2463949