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Wednesday, January 07, 2009

NGOs in working on water/gender in Delhi

NGOs in working on water/gender in Delhi

I am a student in Australia and hope to be undertaking fieldwork in Delhi next year. I am interested in obtaining contact details of NGO's working with women on water-related issues (water scarcity and water security) in the slum areas of Delhi. Also, I would appreciate any local government, or municipal programmes and projects that are specifically targetting water issues within slum areas of Delhi.

 Mary Scott

maryscott29@gmail.com
Showing: 1-1 of 1  
Responses

25 Feb, 2008   |  Bhawna Vajpai
Dear Mary,

Although many organization might be working, I know about Development Alternative on water and environment issue in slums (www.devalt.org), PRIA-Gender (www.pria.org) and water Aid India-Water and sanitation India.

I can be more helpful, if get specific requirement.

Bhawna Vajpai
Water and Sanitation Consultant
http://www.indiawaterportal.org/Network/askq/kb/?View=entry&EntryID=117

Calculations!:Aeration Tank Volume, HRT, MLSS Values.

Calculations!:Aeration Tank Volume, HRT, MLSS Values.
I am working in a STP & ETP plant. I need to know how to calculate:

1. Volume of Aeration tank
2. HRT
3. F/M Ratio
4. MLSS value.

The relevant details of the ETP are as below:

Influent flow = 10 m3 / day
In. flow BOD = 1200 mg / L
In.flow COD = 2200 mg / L
TSS  = 850 mg / L

  Jeyaroopa
  jeyaroopa79@gmail.com
Dear Jayroopa

You may please refer Water & Waste Water Engineering by Metcalf & Eddy.
BOD of effluent is 1200 mg/l. It will be difficult to bring down the BOD by Activated Sludge process to desire permissible limits.

Simplified method of calculation is as below.

Process Activated sludge
Flo3, CUM 10
Type Extended aeration
Food to Microorganism ratio (F/M) 0.15
Total BOD load, Kg BOD*Flow/1000.= 12
Total mixed liquor suspended solids(MLSS) Total BOD/(F/M) = 80 kg
MLSS in Tank say mg/l 3000
Volume of tank, CUM Total MLSS/(MLSS/1000) = 26.6
Retention time, hr 24*Volume of Tank/Flow = 63.84

You can select F/M & MLSS values and optiimise the volume of a tank.
The waste water has high suspended solids therefore sedimentation is must.

Maximum efficiency of Activated sludge process is 95% therefore if you need lower value of BOD in treated effluent then you have to opt two stage process.
For further information please contact

Prof. R. V. Saraf
Director
Viraj Envirozing India Pvt. Ltd.
21 Radhakrishna Near SBI, Paud Road, Pune 38
watersgs@vsnl.net


13 Aug, 2008   |  Taral Kumar

Dear Jeyaroopa,

Though the calculation is not that simple, I will give you a thumb rule. Multiply BOD with Quantity of effluent and divide it by 500 to get aeration tank volume. For example, for 10 cum/day with 1200 BOD, aeration tank volume shall be 10 x 1200 / 500 = 24 cum. That is 2.5 days storage nearly. But that is because the BOD is excessively high.

With best regards,

Taral Kumar
Executive Director
Akar Impex Pvt. Ltd.
Noida, Uttar Pradesh
http://www.indiawaterportal.org/Network/askq/kb/?View=entry&EntryID=343

Monday, October 06, 2008

how much bio gas can i produce


HOW TO START UP AND RUN A BIO GAS PLANT

FOR MORE DETAILS
www.envoprojects.com     9899300371 9810004529


STARTING UP A BIO GAS PLANT

POST NUMBER :08   Date : 02/05/2004
BIO GAS PLANT PROCESS DESCRIPTION:

Biotechnology process
stage one : hydrolysis by hydrolytic bactaria, conversion of extracellular molecules
stage two : thermophilic fermentation based on carbohydrates
stage three : synthesis of volatile fatty acids by acetogenic bacteria
stage four : synthesis of methane by methanogenic organisms

STARTING UP A BIO GAS PLANT:


OPERATION OF BIO GAS PLANT

FLOW CHART: CRUSHER(less than 7mm particle size)----thermophilic Aerobic digester(Temp 55 degree C  )---Mesophilic Anaerobic Digester(37 Degree C )---Manure Pit
Aspect
Bottlenecks
Remarks
CONTROLS
Check for Gas leaks
Check hood , pipe etc. Monthly checking of leakage by pressure system and or with soap water
Cow dung slurry
Make slurry of cow dung and fresh water in the ratio 2kg dung 15 liter water (thumb rule 10% dung of water volume). Fill up the bio digester with the slurry.
Slurry fermentation
Wait for slurry to form gas. It normally takes 3 to ten days.Gas formation can be seen by rising of floating dome or pressure gauge in fixed dome.
Start of Feeding
Start fresh feeding after formation of gas. Start with small quantity of feed material in 1:1 ratio. After 15 days, start feeding full capacity.
Complete Release of first gas produced
Gases should be released to the atmosphere at least three  times at a gap of three days each.
It may be needed to be released more till methane percentage of 60% reached .Do a sample bio gas test to know exact position of gas produced.
Technical
Improper preparation of influent solids
leading to blockage and scum formation
Proper milling and other treatment measures (pre-
soaking, adjustment of C/N ratio); removal of inert
particles: sand and stone.
Temperature fluctuations
Careful regulation of temperature through use of
incorporation of auxiliary solar heating system.
Maintenance of pH for optimal growth of
Methanogenic bacteria
C/N ratio
Appropriate choice of raw material, regulation of
C/N ratio and dilution rate.
Appropriate mixing of N-rich and N-poor
substrates with cellulosic substrates.
Dilution ratio of influent solids content
Appropriate treatment of raw materials to avoid
stratification and scum formation.
Retention time of slurry
Dependent upon dilution ratio, loading rate,
digestion temperature.
Loading rate
Dependent upon digester size, dilution ratio,
digestion temperature.
Seeding of an appropriate bacterial
Population for biogas generation
Development of specific and potent cultures.
Corrosion of gas holder
Construction from cheap materials (glass fibre,
clay, jute-fibre reinforced plastic) and/or regular
cleaning and layering with protective materials
(e.g., lubricating oil).
Pin-hole leakages (digester tank, holder,
inlet, outlet)
Establishment of "no leak" conditions, use of
external protective coating materials (PVC,
creosotes
Occurrence of CO2 reducing calorific
value of biogas
Reduction in CO2 content through passage in
lime-water
Occurrence of water condensate in gas
supply system (blockage, rusting)
Appropriate drainage system using condensate
traps
Occurrence of H2S leading to corrosion
On a village scale, H2S removed by passing over
ferric oxide or iron filings
Improper combustion
Proper air gas  mixing appliances necessary
Maintenance of gas supply at constant
pressure
Regulation of uniform distribution and use of gas;
removal of water condensate from piping systems;
appropriate choice of gas holder in terms of weight
and capacity
Residue
utilization
Risks to health and plant crops resulting
from residual accumulation of toxic materials
and encysted pathogens
Avoid use of chemical industry effluents; more
research on type, nature, and die-off rates of
persisting organisms; minimize long transportation
period of un-dried effluent
Health
Hazards to human health in transporting
night soil and other wastes (gray-water)
Linkage of latrine run-offs into biogas reactors
promotes non-manual operations and general
aesthetics
Safety
Improper handling and storage of methane
Appropriate measures necessary for plant
operation, handling, and storage of biogas through
provision of extension and servicing facilities


DO NOT USE eggshells, Onion peels or left-over bones in this system as they will affect the efficient functioning of the system
Hazards: Methane in a concentration of 6 to 15 percent with air is an explosive mixture. Since it is lighter than air, it will collect in rooftops and other enclosed areas. It is relatively odorless and detection may be difficult. Extreme caution and special safety features are necessary in the digester design and storage tank