FR2694748A1 - Digestion and decantation pit for waste household water - has series of cells connected by staggered slots decanting treated water and retaining sludge. - Google Patents

Abstract

Subterranean decanter and digester for treatment of household waste water. Liq flows slowly through eight cells(A-H) connected by seven staggered slots(1-7). Decanted water only flows through outlet manhole(Z) at exit of final cell(H). Heavy material is deposited at base of pit during flow and light fatty material floats on surface. Waste water enters pit through manhole(Y), with grill, and passes through cells(A-H) via slots(1-7) to outlet manhole(Z) via sunken pipe in final cell(H). Aeration is provided at inlet and outlet. Aerobic digestion at surface and anaerobic digestion in sludge. USE/ADVANTAGE - Treatment of household waste water in small communities. Low cost. Annual cell cleaning. Weekly inlet cleaning.

Description

EXPLANATORY NOTE ON THE OPERATION OF THE DECANTER-DIGESTER
FOR THE TREATMENT OF DOMESTIC DISPOSAL WATER
Objective sought: Optimal treatment of domestic waste water.

Yield possibilities: On the theoretical basis of a volume of discharges corresponding to 200 L of used water per inhabitant and per 24 hours, the type 100 H treats without problem, a total volume of 20 m3 day.

Performances obtained: See the results of analysis of the discharges carried out by the DASS, 19.06.85 - 26.06.87 and 20.10.88.

Principles of operation: (follow the plan) - The domestic waste water arrives in the pit by the Y-eye; they enter cell A, to emerge in the gaze Z, after having circulated slowly and on the surface by the slots 1-2-3-4-5-6 and 7; the slots are arranged in a baffle to avoid a direct correspondence between the slot 1 and the slot 7.

At the end of look Y, installation of a grid for retaining foreign bodies (paper, eggshells, boxes of yogurt, etc.).

To allow the evacuation of suspended matter trapped inside the inlet pipe, two rows of 4 holes of 5 cm are to be drilled the axis of the 1st row is 5 cm from the level of the liquid; the axis of the 2nd row is 16 cm from the same level.

Turbulence: To absorb turbulence possibly caused by a strong inflow of water, the liquid enters cell A, filled like the other cells, over a height of 2.10 m, by a 0.30 pipe which plunges to 0 , 80 from the surface.

Decantation: It is obtained by the rise of light materials on the surface, heavy materials being deposited on the bottom. The water comes out in H by a 0.30 pipe which recovers at an intermediate level, the purified liquid.

Rainwater separators: They are installed only when there is mixed arrival: domestic water plus rainwater.

Pit ventilation: It is essential to ensure good ventilation inside the structure; the permanent supply of oxygen allows the development of bacteria (aerobic) that digest surface sludge; the sludge deposited at the bottom of the tank is digested by bacteria (anaerobes) which live without oxygen supply. The air circulation takes place between the slots from look Y to look Z; if necessary, ventilation can be improved by two air vents placed diagonally on the surface slab.

Emptying the pit: An annual cleaning of the 8 cells seems to be sufficient.

Operating costs: They are limited to the cost of labor and the rental of equipment used to empty the tank.

It is necessary to add the amount of the fees for the analysis of the samples of the rejections, plus the cost of a weekly cleaning of the look Y.

DEPARTMENT of AIN
DEPARTMENTAL MANAGEMENT3
HEALTH AND SOCIAL AFFAIRS
DEPARTMENTAL ASSISTANCE SERVICE
TECHNICAL TO OPERATORS OF
TREATMENT PLANTS
Address
Telephone: Posts
MUNICIPALITY: DOMSURE (Hamlet of Villeneuve)
Visit from: June 10, 1985
Manufacturer Year put into service
Atmospheric conditions: This visit allowed us to observe
Theoretical capacity: ter that this work had a function
satisfactorily. With 30 inhabitants
Equivalent inhabitant connected: connected and a volume of 35 m3, it
is largely dimensioned. A drain
Nature of the effluent: annual sludge is however re
ordered.

Sewage system: Exit sample has been taken
killed downstream, at the outlet of the pipe in
Storm overflow: the ditch. it is within the standards of
rejection.

Lifting
Screening: The Sanitary Technician
Desanding
Degreasing /
LABORATORY Wastewater analysis n 2 1 701
of
HOSPITAL CENTER
47, bd de Brou ASSISTANCE SERVICE
TO OPERATORS OF
01012 BOURG-en-BRESSE PURIFICATION STATIONS
Request
Phone: 22/82/44
DEPARTMENT OF AIN
Ext. 413 DASS

PREFECTURE
(Digester-Decanter)
Origin: DOMSURE treatment plant
Hamlet of Villeneuve
Sampling done on 10.6.85 at 3.30 p.m.
by
EXIT
decanter ph: 7.40
Biochemical BOD oxygen demand:: 23
Chemical oxygen demand COD:: 80
Total suspended matter:: 18
Mineral fraction:: 7
Organic fraction:: 11
Appearance, odor, color ....................

OBSERVATIONS
June 19, 1985
The Director of the Laboratory
DEPARTMENTAL MANAGEMENT
HEALTH AND SOCIAL AFFAIRS
SATESE
VISITING REPORT
Address: Prefecture of Ain Commune of DOMSURE
Telephone: 21.01.26
- Wastewater treatment plant in the hamlet of Villeneuve
- Visit of June 12, 1987 in the presence of
municipal staff - Type of station: decanter - Manufacturer - Year of commissioning: - Theoretical capacity: - Type of effluent: domestic - Equivalent inhabitant connected: 30 - Type of network: unitary - Presence of stray water: no - Atmospheric conditions : variables
- Storm weirs: RAS - Lifting: without - Flow limiter
OPERATING COMMENT
Correct operation of this installation.

The sludge is drained regularly.

An exit sample was taken (see analysis).

It is in level d rejection standards.

The Sanitary Technician,
LABORATORY Wastewater analysis n 2276
of
HOSPITAL CENTER
47, bd de Brou TECHNICAL ASSISTANCE SERVICE 01012 BOURG-en-BRESSE TO STATION OPERATORS
PURIFICATION
Phone. : 22.00.56 Request for
Ext. 413 DEPARTMENT OF AIN
DASS

PREFECTURE
(Decanter-digester)
Origin: DOMSURE treatment plant
Hamlet of Villeneuve
Sampling done on June 12, 1987 at 10 a.m.
PH OUTPUT: 7.71
Biochemical oxygen demand BOD (mg / l):: 20
Chemical oxygen demand COD (mg / l):: 74
Total suspended matter (mg / l):: 25
Mineral fraction .......................:
Organic fraction ......................:
Appearance, odor, color ..................:
Total phosphorus (mg / l) ...........................:
OBSERVATIONS
06.26.87
The Director of the Laboratory
DEPARTMENTAL MANAGEMENT
HEALTH AND SOCIAL AFFAIRS
SATESE
Address: Prefecture of Ain
Phone. : 21.01.26
VISITING REPORT
Municipality: DOMSURE
- Wastewater treatment plant in the hamlet of Villeneuve
- Visit of October 6, 1988 in the presence of
Monsieur le Garde-Champêtre
- Type of station: decanter - Manufacturer
- Year of commissioning: - Theoretical capacity
- Type of effluent: domestic - Equivalent inhabitant connected
- Type of network: unitary about 30
- Atmospheric conditions: good weather - Presence of stray water: no
- Storm overflow: does not overflow
not
-Lifting: gravity arrival -Flow limiter: /
------------
OPERATING COMMENT
Correct operation of this installation.

 The rejection is of good quality (see analysis).

The Sanitary Technician,
LABORATORY Wastewater analysis no 2,722
of
HOSPITAL CENTER TECHNICAL ASSISTANCE SERVICE
47, bd de Brou 01012 BOURG-en-BRESSE A @ A @APLUIIANIS DES SIATIUN @
-------- DE PURATION Tel. : 22.00.56 Request from: @@@@@@@@@@@@@@@@@@
Ext. 413 DEPARTMENT OF AIN
DASS

PREFECTURE
(Decanter-digester)
Origin: DOMSURE treatment plant (Villeneuve)
Sampling carried out on 6.10.1988 at 3 p.m.

PH OUTPUT ..........................................: 7.16
Biochemical oxygen demand BOD (mg / l): 4
Chemical oxygen demand COD (mg / l): 40 Total suspended matter (mg / l):: 8
Mineral fraction .....................:
Organic fraction ....................:
Appearance, odor, color .......................:
Total phosphorus (mg / l) ......................:
OBSERVATIONS
OCTOBER 20, 1988
The Director of the Laboratory
Figure 1 shows a plan view
2 2 represents a section on look Y
3 3 represents a section on manhole Z
4 shows a section on exit from compartment H
5 represents a section AA
6 represents a section BB
The capacity is as follows
Cell A: 2 m3 755 Cell E: 2 m3 610 "B: 2 m3 755" F: 2 m3 610
CC: 2 m3 610 "G: 2 m3 755
"DD: 2 m3 610" H: 2 m3 755
TOTAL .... 10 m3 730 + 10 m3 730 = 21 m3 460

Claims (1)

 CLAIM Decanter-digester for the treatment of domestic waste water, characterized in that it is a buried structure and in that the liquid flows slowly and at the surface through seven slots placed in a baffle (1 to 7); only the decanted water flowing in a manhole (Z) at the exit of a last cell (H), your heavy matter being deposited at the bottom of the pit during the circuit and the light fat remaining on the surface .