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Publication numberUS3374065 A
Publication typeGrant
Publication dateMar 19, 1968
Filing dateDec 16, 1964
Priority dateDec 20, 1963
Publication numberUS 3374065 A, US 3374065A, US-A-3374065, US3374065 A, US3374065A
InventorsHideo Suzuki
Original AssigneeToyo Giken Company Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Biochemical oxygen demand continual detecting apparatus
US 3374065 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

March 19, 1968 HIDEO SUZUKI BIOCHEMICAL OXYGEN DEMAND CONTINUAL DETECTING APPARATUS Filed Dec. 16, 1964 INVENTOR United States atent Oilice 3,374,065 Patented Mar. 19, 1968 ABSTRACT OF THE DISCLOSURE An apparatus for the automatic detection of the B.O.D. value, comprising a container and means for injecting a the volatile organic acid alkalinity contained in the stream to be measured.

After due experimental studies performed by the inventor, it was successfully discovered that organic substances in water streams relate to the B.O.D. value and usually consist of acetic acid, propionic acid, butyric acid, etc; and that -50% of the B.O.D. value may always be correlated with the lower fatty acid content.

Also, fatty acids having comparatively large molecules together with unsaponifiable matters other than suspended matters may, however, contain, fatty acids which are always the central base of those substances.

In order to clarify the aforesaid description, the following comparative table between the rate of volatile acidic alkali and the measured value of the B.O.D. is provided:

Chemical Aiter Bio- Kind of soils (p.p.m.) River- River- Rivertreated chemical Drain Drain water water water urinate treatment (A) (B) water Volatile acid alkalinity by direct titration 26.9 19.8 15.8 607.6 75.2 34.5 44.2 Organic acid by steam distillation method 43.7 23.4 13.2 380.6 127.2 65.0 54.9 34. 3 30. 9 9. 1 1,330.0 61. 3 117. 5 108. 1

test material into the container. Means are provided for injecting a non-organic acid into the container to form a mixture. Means for mixing and heating the mixture causes a removal of the basic group, such as carbonate, bi-carbonate or carbonate anhydride, etc. During this stage, means for continuously detecting the lowering pH value causes a valve to close, thereby closing the nonorganic acid injecting means when a low pH value is reached. Means for injecting an alkaline having a pre determined density into the mixture is provided and a recording meter is provided for showing the pH value increase. A measuring means determines the B.O.D. value by measuring an operating period of the alkaline injecting means over a pH value range indicating the volatile organic acid alkalinity.

The present invention relates to an apparatus for continuously detecting and estimating B.O.D. (Biochemical Oxygen Demand) value existing in drainages, rivers, etc.

In spite of a serious need for sufficient detection of the B.O.D. value in the public health field, there has never been, heretofore, an appropriate method for estimating the B.O.D. value on a continual basis due to a difficulty of measuring the varying B.O.D. in flowing drain water.

It has been desired to maintain drainages and rivers within :a predetermined or normal B.O.D. value; however, an exact measurement of the B.O.D. value in water streams could not be satisfactorily achieved due to the continuous change of the B.O.D. value.

It is an object of the present invention to provide an epoch making apparatus for continuously estimating the B.O.D. value in water streams.

It is another object of the present invention to provide an apparatus which substantially utilizes a close chemical relation which exists between volatile organic acid alkalinity and the B.O.D. value.

In accordance with the present invention, the B.O.D. value in water streams can be precisely measured continuously, even though the B.O.D. value is irregular.

A further feature of the present invention is that the B.O.D. value can be indirectly measured by obtaining As apparent from the above table, a mutual relation is confirmed between the volatile acidic alkali and the B.O.D. value.

In order to estimate the B.O.D. value in water streams, the present invention provides a detecting apparatus which essentially consists of a complete line of an automatic pumping device together with other means whereby the volatile organic lacid alkalinity and the B.O.D. value can be automatically measured with a continuous recording system.

In detail, this apparatus is constructed with a testing tube, an automatic sampler which takes the proposed sample in the base of a periodic time interval, a pH meter, an acid reservoir, .an alkali tank, a pump for a predetermined volume, a recorder for the B.O.D., etc.

With these and other objects in view, which will become apparent in the following detailed. description, the present invention will be clearly understood in connec tion with the accompanying drawing, in which:

FIGURE 1 is a schematic diagram of an embodimnt of the present invention; and

FIG. 2 is a graph showing a mutual relation between the B.O.D. value (p.p.m.) and the volatile organic acid alkalinity. I r 1 Referring now to the drawing, a test material is initially conducted by a pump 15 into a testing tube 5 and an electric switch 1 is turned on.

A sampler-timer 2 is then actuated and an acid is supplied into the testing water of the testing tube 5. At the same time, valve 6, attached to an outlet pipe of the test material 5', and provided on the testing tube 5, is closed and a mixing treatment with heat is performed by mixer 7 together with heater 8 as switch 8' is turned on. At the moment when the pH contained in the test material shows a lower value than any desired value, for instance, such as 3.5, an indicating signal is transmitting to a pH meter 10 by means of a glass-electrode 9 on which a fixed thermostat is contained in the testing tube 5, whereby a valve 3 of an acid tank 4 is closed by an operation of a shifting switch 11 which is connected to the pH meter 10.

On the other hand, heater circuit 8 'of the testing tube 5 is simultaneously cut within five minutes, being effected by the timer 2, and an alkaline solution having a 3 normal cardinal number is supplied into the testing tube 5 at a constant speed by means of a quantitative pump 13 fixed in the tank 12. If the pH contained in the test material shows a value, for instance 4, an operation of a B.O.D. indicator 14 is commenced.

The B.O.D. indicator 14 is designed so as to record an operating period of the quantitative pump 13, and accordingly a volatile organic acid alkalinity is shown in the indicator through the quantity of the alkaline solution supplied by the quantitative pump 13.

Thus a scale on the indicator may be directly read as the B.O.D. value, for instance, from a reference line A.B. y=2.18x+34.8 (where, y=B.O.D. in p.p.m., and x=volatile organic alkalinity in ppm.) as shown in FIG. 2. Further, OY and OX in FIG. 2 respectively show the B.O.D. in ppm. and the volatile organic acid alkalinity in p.-p.m.

Assuming the pH becomes 7, then the alkaline quantitative pump 13 stops and the indication of the B.O.D. recording indicator 14 is terminated. Then, the valve 6 of the outlet pipe 5 for the test material on the testing tube 5 opens and supplies the test material into the testing tube 5. At this moment, a test material, readily measured, is exhausted through the outlet pipe 5' being effected by an operation of the pump 15 :being controlled by the sampler-timer 2. Then, 'by supplying the test material into the testing tube 5, another test material supplied previously is accordingly replaced and a normal water level of the test material may be maintained in the testing tube since the pump will be automatically stopped. If the sampler pump 15 suspends its operation, the same state as the commencing operative state occurs in which the electric switch is on and the aforesaid process can be repeated.

Now, for a further appreciation and better understanding of the present invention, three experimental examples are provided.

Example 1 With a 500.00 cc. testing tube, successive titration of acid and alkali of which the cardinal number is N/lO was performed at a chemical treating laboratory on drainage.

After twelve hours of successive operation with ten minute time intervals for thirty two times, the reference line shows y=1.33x+605.7 (where, y=B.O.D. in p.p.m., and x=volatile organic acid alkinity in ppm). The scale indication on the recording paper detected the reference formula.

Example 2 With a 300.00 cc. testing tube, the B.O.D. value existing in the neighborhood of an overflowing reservoir outlet was measured twenty-one times. Each measurement was processed for fifteen minutes having been kept continuously for twenty-four hours, successively.

The reference line detected was y=2.18x+34.8 (y=B.0.D. in p.p.m., and x=alkaline degree of organic acid in ppm.)

Example 3 With a 300.00 cc. testing tube, and fifteen minute measurements, the B.O.D. value in river water was successively made twenty-two times in two days. The respective 4 time intervals between experiments were two hours. The reference line showed y=1.55x0.77 (y:B.O.D. in p.p.m., x=volatile organic acid alkalinity in p.p.m.).

As is apparent from the above examples, the present continuous B.O.D. detecting apparatus can be easily utilized for detecting the B.O.D. value such as, for example, from river water, drain water and any type of sewages by means of classifying scales, testing tube capacities, cardinal numbers of acid and alkali of the recording form into several groups depending upon the proposed drainage to be tested.

The present B.O.D. detecting apparatus provides a remarkable means for detecting B.O.D. in river water, drain water and any other type of sewages by usefully utilizing a close chemical relationship between volatile organic acid alkalinity and the B.O.D. value.

The present invention successfully provides an inventive detecting for the B.O.D. value without being affected by the continuous changes of the water quality.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claim.

What I claim is:

1. An apparatus for the automatic detection of the B.O.D. value of a test material comprising a container used as a testing tube,

means for injecting the test material into said container,

means for injecting a non-organic acid in o said container to form a mixture,

means for mixing and heating said mixture,

means responsive to a predetermined low pH value for closing said non-organic acid injecting means, means for injecting an alkali having a predetermined density into said mixture at a predetermined rate, recording meter means for showing the pH value increase, and

determining the B.O.D. value by recording the time during which the alkali is injected until the pH reaches a predetermined high value, whereby the total alkali added is determined and is a measure of the fatty acid content of said test material and correlated to the B.O.D. value thereof, whereby the B.O.D. value of said test material is determined.

References Cited UNITED STATES PATENTS 2,928,782 3/1960 Leisey 23253 X 3,073,682 1/1963 Lindsley 23253 3,192,017 6/1965 Kruger 23253 3,246,952 4/1966 Dawe 23253 OTHER REFERENCES Gaffney et al.: Biochemical Oxidation of the Lower Fatty Acids, Water Pollution Control Federation Journal, vol. 33, pp. 1178-1181, November 1961.

MORRIS O. WOLK, Primary Examiner.

R. E. SERWIN, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2928782 *Feb 9, 1956Mar 15, 1960Standard Oil CoAutomatic titrator
US3073682 *Aug 4, 1958Jan 15, 1963American Enka CorpAutomatic titrator
US3192017 *Jul 3, 1962Jun 29, 1965Beckman Instruments IncContinuous recording titrator
US3246952 *Aug 13, 1962Apr 19, 1966E H Sargent & CoTitrating and recording apparatus
Referenced by
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US3466146 *Apr 1, 1966Sep 9, 1969Minerais Et MelauxInstallation for automatic attack of materials with a view to their chemical analysis
US4088575 *Feb 22, 1977May 9, 1978Hilty Jon DAutomatic system cleaner for remote monitor
US5531960 *Nov 28, 1994Jul 2, 1996Madison Metropolitan Sewerage DistrictAutomated dissolved oxygen and biochemical oxygen demand analyzer
US5976888 *Dec 7, 1998Nov 2, 1999Biochem Technology, Inc.Method for measuring NOx in biochemical processes
US6106718 *Jun 30, 1999Aug 22, 2000Biochem Technology, Inc.Enhanced denitrification process by monitoring and controlling carbonaceous nutrient addition
US6143246 *Aug 18, 1998Nov 7, 2000Biochem Technology, Inc.Apparatus for measuring ammonia in biochemical processes
US6248595Apr 23, 1999Jun 19, 2001Biochem Technology, Inc.Method of measuring a nitrification rate for liquids
US6416652Jul 18, 2000Jul 9, 2002Bio Chem Technology, Inc.Method for measuring ammonia in biochemical processes
WO1999051531A1 *Apr 6, 1999Oct 14, 1999Theodore T RonaldWaste treatment system and method
U.S. Classification422/79, 436/55, 210/85, 436/62
International ClassificationG01N33/18, G01N31/16
Cooperative ClassificationG01N31/16, G01N33/1806
European ClassificationG01N31/16, G01N33/18A