IR-DRDO BIO-TOILETS

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 What is Bio-Toilet ( Bio-Digester Toilet )?

• Bio-Toilet is an innovative technology for disposal of

solid human excreta by biological decomposition in
an eco-friendly, economical and hygienic manner.

• A Bio-Toilet is a complete waste management

solution which convert solid human excreta to
Biogas and pure water, with the help of a bacterial
Inoculum.
 IR-DRDO BIO-TOILETS
• An MOU was signed between DRDO and IR on 29.03.10
regarding joint technology development of ‘DRDE Bio-digester’
for IR toilet system.
• It is one of the major flag bearers of “Swach Bharat” mission.

• IR is putting all effort to make bio toilet successful. Bio-toilet

has now become an essential part of coaching stock.

• So it has become necessary to have fully fledged knowledge of

bio-toilet system for the staff working at bottom line
 Environment Friendly Bio-Toilet System

• To overcome the environmental degradation and

maintain the hygiene in railway premises, IR in
association with DRDO (DRDE/Gwalior) has
developed IR-DRDO Bio-toilets.

• Bio-digester filled with ‘anaerobic bacteria’ converts

human waste into liquid and gases.

• This gases escape to atmosphere and treated waste

water is discharged after chlorination.
 The residual water from Bio-Toilet

• Is colorless, odorless and devoid of any solid particles.

• Requires no further treatment / waste management.

• Can be used for irrigation purposes.

Aims of Green toilet - Zero-Defecation on the ground
• The first prototype rake with IR-DRDO Bio-toilets is
running successfully in Bundelkhand express since
18th Jan.2011.

• IRs have decided that all coaches should be

converted to work with bio-toilet by Dec.2018.
 Benefits of green toilet

• Completely Environment & user Friendly.

• Does not produce any foul smell.
• Uses Natures products to clean human waste.
• Preserves ground water quality.
• Eliminates load on existing Sewerage System.
• Prevent damages to tracks due to corrosion.
• Improves aesthetics at Railway Stations
 Advantage of Anaerobic bio-toilet

• Require less maintenance

• Simple in design

• Easier Retro fitment on existing coaches in service

• No oxygen and sunlight required for processing.

Working of Anaerobic System
 Brief about anaerobic bacteria
• Doubling its population within 6 to 8 hrs.

• Dominates and de-composes matter into liquid and

gases.

• Can be kept for 3-4 months at ambient temperature in

bio-digester tank

• Can withstand subzero temp.as well as up to 600 C.

• Cold temperature would not affect the inside

processing (because anaerobic process is exothermic in
nature)
 Advantage of IR-DRDO Bio-Digester over
Conventional Toilet system
• No bad smell in toilets from the tanks
• No infestation of Cockroaches & flies
• Faecal matter in the tank not visible
• No clogging of digester
• Effluent is free from odour and solid waste
• No maintenance required
• Reduction in organic matter by 90%
• No requirement of repeated adding bacteria/ enzyme
• No need of removal of solid waste
 Main parts of the Bio digester tank
• 1. SS tank with 06 partition walls inside the tank
• 2. Poly grass mats for protection of bacteria inside
the walls.
• 3. Ball valve with handle for operation during
emergency for making toilet direct discharge in case
of choking. (P trap type)
• 4. SS fasteners in place of MS on tank covers.
• 5. Stronger bonding of Colonized rubber mats with
vertical walls.
 Important Dimensions, Volume & Weight
of Bio-digester Tank for ICF/RCF Coaches
• 1. Size – 1150 x 720 x 540 mm (LxWxH)
• 2. Total Volume of Tank – 400 ltr.
• 3. Effective Volume of Tank – 300 ltr.
• 4. Empty Tank weight – 110 Kg.
• 5. Full Tank Weight – 410 Kg.
• 6. Height from Rail level - 220 mm
 Other components of Bio-Digester Tank
for ICF/RCF Coaches
• 1. Mounting Bracket - 04 Nos
• 2. Safety Rope - 04 Nos
• 3. Locking Plate - 08 Nos
• 4. Hex. Head Bolt & Hex. Nut (M16) - 16 Nos each
• 5. Spring Washer (B16) - 16 Nos
• 6. Hex. Head Bolt (M8 X35) - 16 Nos
• 7. ‘U’ Bracket(8 X20 X38) - 08 Nos
IR-DRDO Bio-digester Tank for ICF/RCF Coaches
Sketch of Bio-Digester Tank
Partition walls of Bio-tank
 IR-DRDO Bio-digester Tank for LHB Coaches
• Size 1680X 580 X547 MM with the provision of 02
no’s inbuilt C-Type mounting system along the length
of the tank.

• Each mounting is with the provision of 02 nos. M16

Size bolts which are tightened with the inner and
outer head stocks.
IR-DRDO Bio-digester Tank for LHB Coaches
 Important Dimensions ,Volume & Weight of
Bio-digester Tank of LHB Coaches
• 1. Size: 1680x580x547mm (LxWxH)
• 2. Total Volume of Tank - 600 lt.
• 3. Effective Volume of Tank – 450 it.
• 4. Empty Tank weight – 120 Kg.
• 5. Full Tank Weight – 425 Kg.
• 6. Height from Rail level -220 mm.
 Variants of Bio-Toilets
• Initially Railway tested several variants of bio-toilets
designed jointly by DRDO and IR

• Second variant with manual slider and P-trap was

selected for retro-fitment in coaches as per JWG
Gwalior on 01.04. 2011.

• However with due course of time, all these variants

have been changed and no variant is in use presently.
Waste flow path in the tank
 Mounting arrangement of Bio-digester
• 1. Initially J-Bracket welded with head stocks, and
brackets were part of coach body. Bio-tank rests over
the J-bracket. (As per RDSO letter no MC/CB/LF/Anaerobic ,dated 21.06.2012)
 Disadvantages of J-brackets

• I. J-brackets has higher tendency of corrosion

especially at the edges.
• II. Difficult to repair during retro-fitment because it
involves down hand welding.
• III. Welding of J-brackets fails eventually.
• IV. Difficult for repair and maintenance of welded
design J bracket mounting arrangement,
 2. Direct /Bolted type mounting arrangement
(Positive Mounting)
• There are two types of bolted design bio digester in
use-I) is being used for fitment in Production Unites
and II) one is for retro-fitment in Zonal Railways.
 2.(I) C- Mounting bracket- 29.04.14

• ‘C’ mounting bracket has extended member of both

the tank bracket and head stock channel bracket.

• Bracket of tank rest over the surface of channel of

under frame which makes a shape of ‘C’.

• This is easy to retro fit without any high tendency of

corrosion.
C- Mounting bracket
 2.(II) Direct mounting bolted design.

• For strengthening of the Bio digester tank, alternate

designs have been developed by RCF and approved
and adopted by RDSO(letter no MC/CB/LF/Anaerobic dated
02.03.2016)

• This has many advantages as-

– I. It is easy to mount.
– II. It has almost nil corrosion.
– III. Has high strength for holding of tank
Direct mounting bolted design.

CG 15036-3-2 CG 15036-3
 Direct mounting arrangement
(Positive Mounting)
Types of coaches Bolted design bio digester As per RDSO drawing no.
For ICF design On C- Channel CG-11081
coaches (or RCF dr. no MI0055 10)
For retro-fitment CG-14053 alt-4
For LHB coaches On C-channel
For retro-fitment CG-18100
For Hybrid coaches On C-Channel
For retro-fitment CG-18126

For old CBC fitted ICF For retro-fitment CG-15041

type coaches
For DEMU coaches For retro-fitment CG-14053
For MEMU/TC For retro-fitment MI005854
coaches
 Provision of S-Trap in Bio-Toilets
• In many cases it was found that rubber connector was
torn/ damaged which were causing leaking/spreading
of faecal material over tank which gives foul smell
during rolling-in, rolling-out. Moreover, it is very
inhuman for maintenance staff to work under that
coach,
• Due to use sharp edged picking tong or choke remover
by housekeeping staffs the rubber connector gets
damage which causes leaking/spreading of faecal
material over tank.
• Due to chocking en-route, ball valve is operated to clear
the choking. After the blockage is cleared, ball valve is
left unclosed or partially closed.
 Interface
(between P-trap and pan)
 TPE Connector
Spread of feacal
matter over tank

Connector between
pan and P-trap(60mm)
 S-Trap v/s P-Trap

S-trap P-trap with Ball valve

 S-trap (as per 15th JWG committee)

• So it was decided to introduce a new system to

eliminate above problems, to adopt S-trap in all
coaches

• Now 100 mm dia of S-trap has been recommended

as per RDSO letter no MC/CB/LF/Anaerobic dated
06.10.17.

• Now all coaches turning out from PUs/workshops /

depots are S-trap fitted bio-digester tank only.
 Main features of S-Trap Design
• I. Complete elimination of foot paddle, Ball valve, P-
trap and flexible rubber hose connector from tank
unit.

• II. In place of existing 60 mm dia. P-trap, a ‘S’ band of

100 mm dia. (ID) is directly coupled to commode pan

• III. Less maintenance is required, as there is no

rubber hose connector and no wear and tear of
rubber connector during cleaning.
Drawing of S-Trap
Retro-fitment of S-trap in existing bio-digester
• It has been decided by RDSO to adopt 100% S-trap in
all coaches

• All the coaches to be turned out from POH should

have 100 mm(against 150mm) lavatory outlet
(Drawing no CG-17045 )and also fitted with S-trap.

• Retro-fitment procedure of S-Trap(RDSO Drawing No.

CG-16008).

• IR-DRDO Bio-Toilet with P-trap (RDSO Drawing No

CG-14053).
Retro-fitment of S-trap in existing bio-
digester
• Design of S-trap has already been adopted by RCF for
fitment of Bio-Toilets in LHB Type Coaches (RCF
Drawing No. MI005710 Alt – ‘f’or latest alteration)
Applicable Designs of Bio-Toilet tanks for
Coaching Stock
 Fitment of SS standard dust bin
• It has been finalized by RDSO in the Bio-Toilets of
ICF/RCF design coaches and circulated to zonal
railways vide RDSO letter no. MC/CB/LF dated 12.09.2013
with drawing no. CG-13031 (for dustbin)
• Kept it inside lavatory under wash basin
 Qualifying criteria for the residual thickness of the headstock
on which retro fitment of Bio-Toilets in Existing Coaches

• “Reduction of cross section of outer & inner

head stock beams may be allowed up to 15%
i.e. residual thickness 8.5 mm for inner head
stock and 6.8 mm for outer head stock.
 Procedure for retro fitment of Bio-Toilet tank
on ICF/RCF design BG Coaches
• Mark the location of each mounting bracket for
making holes of specified size on inner and outer
head stock C channels as per RDSO drawing no. CG-
15036

• Fill bacterial inoculums about 150 liters obtained

from DRDE Gwalior or their approved vendor just
before putting coach into service.
 Parameters of Bio Toilet effluent
• Lab samples should be collected as per testing
scheme circulated by RDSO & results should be
recorded in prescribed Performa’s.
Sl No. Parameter (as per APHA Test Recommended Values
Method).

pH 6 to 9

COD levels Max 1800 mg O2/Litre(PPM)

Faecal Coli Forms count(By MPN Less than 107CFU/100 ml

method)
 Performance Parameters of Inoculum

• Record of these 04 tests should be maintained at

Bacteria Generation Plant-
Parameter (as per APHA Test Method). Recommended Values

pH 6.5 to 7.5

Bio-Gas production test As per test scheme.

Inflammable
Percentage methane > 40%

MPN for methanogens count (MPN/ml) >103

 Maintenance Instructions for Coaching
Depot Staff
• The preventive maintenance schedule for
maintenance of coaches being followed in IR

• Time schedule for maintenance of the IR-DRDO Bio-

toilet system are issued by CAMTECH under
Guidelines for AMOC for Bio-toilets.
List of cleaning agents used in mechanized
coach cleaning in Bio-Toilet system
Maintenance of the Bio-toilet systems and
Guidelines for handling of Bacteria
• Visual inspection of complete toilets system including
under slung equipment’s.
• Toilet chute to be cleared in bio-toilets if there is
choking.
• Checking the toilets system for any deficiency.
• Collection and transportation of sample as per the
test scheme.
• Charging of chlorine/KMNO4 tables and examination
of chlorinator.
 Checking of following equipments /repair /
replacement for proper functioning
• i. Leakage in piping, flush system, tank, valves,
pressurize, PLC, pneumatic valves, etc.

• ii. If there is ball valve (P-trap), replace it with S-trap

on priority basis.

• iii. Charging of Bio-culture if required (based on test

reports).
Check List for Maintenance Staff
Check List for Maintenance Staff
 Maintenance proforma for bio-toilets

• On arrival all bio-toilets are need to be checked

completely by nominated staff.

• After complete inspection(jointly with contractual

supervisor in case of AMOC ) proforma for on arrival
and again before departure from washing line will
be filled up by the concerned staff.
Daily Maintenance proforma for bio-toilets.
 DO’s and DON’Ts for Maintenance in
Open Line
• DO’s:
• Ensure J-brackets/C-Type mounting is in sound condition & all
fasteners are intact.

• Ensure availability of chlorine/Kmno4 tablets in each trip.

Provide if required.

• Check condition of 8/10 mm dia SS Safety wire rope for

proper securing and any damage near edges of Bio-Toilet
tank. Maintain 5 mm gap between wire rope & tank body.

• Ensure functionality of flush buttons/ lever & water taps for

adequacy of flushing in pan
 DO’s:
• Ensure no foul smell inside Toilet.

• Ensure overall cleanliness level in the Bio-Toilet.

• Ensure availability of Stickers/Notices for Users and

Maintenance staff in Hindi/English & regional language of
the originating & destination station.

• Ensure no leakage from S-trap.

• Ensure availability of sufficient choke remover devices in

the depot for removing S-trap choking.
 DO’s:
• Ensure availability of Evacuation machine in working order
in Coaching depot & evacuation record of tanks is being
maintained properly.

• Ensure Broad-casting of short video film on Bio-Toilet at

passenger station for awareness of passengers.

• Clean hands with detergent/soap after handling of the

bacteria

• Ensure AMOC guidelines are being followed strictly in the

depot as recommended in CAMTECH Doc.
IRCAMTECH/GWL/M/Bio-Toilet/AMOC/1.0-Aug-2015
Don’t
 Facilities required in Coaching Depots for
maintenance of coaches fitted with Bio-toilets
 Trouble-shooting of Bio-Toilet System for
Coaching Depots staff.
• Method of S-Trap Choke Removing :by en route
cleaning staffs and housekeeping staffs.
• 1. Flush the water in lavatory to make a water column.

• 2. Now apply “choke Remover” in to the Pan with

pressure 2-3 times, due to this action, S-trap will be
cleared of obstruction.

• 3. In case, S-trap is still having obstruction in side, the

“choke Remover” should be applied again in the Pan
by flushing Bio-toilet.
P-Trap/S-Trap Choke Removers
Garbage Picking Tongs
 Remedial action
in case of a sample fails in effluent testing
• i) If a sample from a given bio-toilet fails to comply with revised targets in
respect of any of these three parameters (i.e. pH, COD and Faecal
coliform), the effluent quality should be tested twice more at monthly
interval.

• ii) If the sample fails on any of the two repeat occasions in any of the three
parameters, then corrective remedial measures should be taken by zonal
railways.

• iii) In remedial action complete tank should be evacuated through

evacuation machine.

• iv) After evacuation bio-digester should be charged with 120 litres of fresh
tested inoculums.

• Consolidated all the test reports (In-House/Govt. Approved Labs) of

effluent discharge shall be submitted to RDSO on 06 monthly bases.
 Technical requirement of chlorine tablets
• The tablet size should be 78 mm dia and weight should be of
approx. 200 gms.

• The tablet should have active molecule of di-chloro-isocyanuric-

acid.

• It should have effective chlorine of > 50% chlorine.

• The tablet should be formulated for sustained release (should last

for at least 21 days in tap water).

• Moisture content should be < 4%.

• The tablet should be stable during storage for at least 01 years.

di-chloro-isocyanuric-acid.
Technical requirement of chlorine tablets

• Identification marking: Each chlorine tablet shall

have manufacturers name /Logo, month and year of
manufacture.

• Packing: should properly protect against moisture,

rubbing, impact, and scratches during handling,
transportation and storage.

• Warranty: for conformance to quality for a period of

12 months from the date of supply.
 Abbreviations
• AMI – Anaerobic Microbial Inoculum.
• CFU – Colony Forming Units.
• COD – Chemical Oxygen Demand.
• FC – Faecal coliform count.
• FRP – Fibre reinforced plastic.
• HRT – Hydraulic Retention Time.
• MPN – Most Probable Number.
• PUF – Polyurethane foam.
• RCC – Reinforced Cement Concrete.
• TC – Total coliform count.
• TDS – Total Dissolved solids.
• TS – Total solids.
• VFA – Volatile Fatty Acids.
• VS – Volatile solids.
• APHA -American Public Health Association
• AMOC-Annual maintenance of operating contract
 ISO Standard
• ISO 9000: QMS- Fundamentals and vocabulary
• ISO 9001: QMS- Requirements
• ISO 9004: QMS- Guidance for performance
improvement
• ISO 19011: Guidelines on quality and/or
environmental management systems auditing (To be
published)
• The revised ISO 9001 and ISO 9004 standards were
developed as a "consistent pair" of standards.
• ISO 9001:2008 is focused on the customer.
 .

THE END