– Dr N B Mazumdar

Multiple solid waste management:

how to foster recovery in developing countries ?

Closing Conference

June 8th -9th 2017, AFD : Paris

�  Dr N B Mazumdar Sulabh, Director General, Delhi Ex- Senior Technical Consulting Adviser IL&FS Waste Management and Urban Services Ltd., New Delhi 2005-2016 Previously : -Consultant to TERI -Chief (Projects), Waste Management Cell, HUDCO -Director, Sulabh International Institute of Technical Research and Training - Consultant to the WHO in China Worked as a consultant to the WHO in China in the field of Environment Management (low-cost on-site sanitation)and training of professionals in Sanitation Management.

Thermal WtE The new saviour or generator

of trouble??

�  An average of 9000 tons/day is collected in Delhi

�  Since 1975, 23 landfills have been closed and in 2017, 4 are currently functionning

�  Increasing price and decreasing availability of land has been the prime driver for thermal WtE

�  Ease of selling electrical power compared to organic

manure (compost) with its low nutrient and requirement of warehousing (seasonal agricultural application) is the other driver

�  Favourable revision of power tariff during the last 2

years has also given a large boost

�  Between 2012-2017 three thermal waste to energy plants have been set up in Delhi (next slide)

�  The first one at Okhla was based on mass burn. The

plant was built quickly in about 18 months and has been running since May 2012 full capacity

�  However, in the initial 3 years it had emission control

issues, which were gradually resolved �  This plant has habitation at close range and there have

been public objection and court cases but it is operational

  Location

  BOOT operator

  Start date  

  MSW intake as per

concession agreement

  Actual

(TPD)

   

  Mass burn

or through RDF  

Power generation

MW

– Designed capacity

– Average generation  

  Number of boilers

  Grate type  

  Emission norm followed  

Okhla

  Jindal

Timarpur Okhla WM Co. Ltd.

  2012

   

  1950

  2000  

  Mass burn  

  16

  22

(20% internal consumption)

  18  

3 (any 2 working)

  Reciprocating inclined

grate

  Martin  

  DPCC**

  (Delhi Pollution Control

Committee)  

  Ghazipur

  IL&FS Environment

  2016

   

  1300  

  RDF followed by

incineration  

  12

  8

(30% internal consumption)

   

  01

  Reciprocating inclined

grate

  Keppel Sieghers  

  Euro norm  

  Bawana

  Ramky

  2017

         

  4000

  Present intake 1400 TPD

     

  Mass burn

  Actually old RDF is being incinerated

   

  24

   

16  

  2

  Reverse acting

reciprocating inclined grate

  Covanta  

  DPCC**  

�  Thus in thermal WtE there are two distinct approaches – (i) direct mass burn and (ii) preparation of RDF (crude SRF) followed by combustion of the RDF

�  Both sides have advantages and disadvantages and for the average waste in India the jury is yet to be out

�  Both systems need to be studied closely in working

commercial plants

�  In the WtE plant at Ghazipur, the boiler fuel is prepared in he form of RDF

�  The material is picked up from the MSW pit and

subjected to manual segregation on slow moving conveyors, passed through magnetic separators

�  Then the sorted material is passed through a trommel

with 100 mm round openings and a bag ripper �  The material passing through (<100 mm) is passed

through a combined trommel with 25 mm and 16 mm openings

�  The material between 16-25 mm is considered organic and sent to compost plant

�  Material below 16 mm is inert and is sent to the landfill �  The material above 100 mm size is sent to the

shredders �  The shredded material is allowed to be mixed with the

25-100 mm fraction from the trommel �  Combined shredded material sent to rotary dryer

followed by air density separator. The dried material is RDF (light combustible fraction)

�  Treated sewage water is used in the plant for process water

�  The primary air and secondary air is heated using

steam coil air pre-heater (SCAPH) �  The environment management plan consists of

i. Flue gas treatment plant (FGTP) ii. Odour control iii. Leachate treatment plant iv. Management of solid residues v. Noise control

�  It is a complex system comprising the following steps: �  Manual segregation of chlorinated plastics �  Temperature control in furnace �  Selective non-catalytic reduction agent (SNCR) for NOx

by ammonia / urea injection in the boiler �  Multi-pass boiler to capture maximum particulate

matter which go out with bottom ash �  Lime injection for neutralising acidic gases and

precipitating heavy metals. The flue gases from the boiler goes into a semi-wet reactor where lime injection is done

�  Activated carbon is injected when the treated flue gas from the semi-wet reactor goes to the bag filter. Activated carbon helps in adsorption of mercury vapours, odorous constituents, dioxins and furans

�  The bag filter removes remaining SPM in the form of fly ash

�  The cleaned air is pushed by an ID fan through the

chimney �  The chimney has continuous emission monitoring

system (CEMS) which can be viewed by the public through website and display boards.

Parameter

   Unit   Test value   Euro norms   DPCC norms  

PM

   mg / Nm3   6   10   30  

NOx (as NO2)

   mg / Nm3   57   200   350  

SOx (as SO2)

   mg / Nm3   0   50   100  

CO

   mg / Nm3   31   50   100  

HCl

   mg / Nm3   11.8   10   50  

Total dioxins and Furans  

ng TEQ / Nm3   0.015   0.1   0.1  

�  Collection cum equalization tank �  Chemical treatment (addition of ferrous salt, lime and

polyelectrolyte for precipitating SS, heavy metals, removal of colour etc.)

�  Stripping tower - Aeration for reduction of ammonia �  2-stage biological process – anaerobic hybrid reactor

followed by aeration

�  Filtration – treated water used for horticulture in plant premise

�  This project has social inclusion as an important component

�  Eligible rag-pickers have been employed in the WtE plant according to their capability

�  Alternative livelihood for the women rag-pickers was a big concern

�  An organization named ‘Gulmeher’ has been started where women are trained to make artefacts from waste flower, hand made paper etc.

�  The company helps them with marketing of these materials

�  Creches for babies of working mothers, functional literacy, helping with opening bank accounts etc.

The challenges of Composting

�  Applicable quality norms for compost produced from MSW FCO 2009 and PROM 2013

�  Therefore whoever undertakes to prepare MSW based compost and sells the same, requires a licence to market / sell in the concerned state in India

�  They are liable for official inspection and analysis of product (compost)

�  Therefore quality management is essential throughout the manufacturing process

�  **FCO – Fertilizer Control Order, PROM – Phosphate rich organic manure

Location

  Boot

operator

   

  Start date  

SWM intake capacity (TPD)

Designed

Actual  

  System  

  Storage for

compost  

  Leachate treatment

facility  

Okhla

  IL&FS Environment

   

  2009  

  300

200  

Aerobic windrow composting + RDF  

  One month  

  Yes  

Bhalswa

  Excel Industries    

  1999  

  500

Closed  

Aerobic windrow composting    

  No  

  No  

Bawana

  Ramky

   

  2011  

  1400  

Aerobic windrow composting + RDF

   

  One month

Yes     

�  At the Okhla compost plant experiments were done with aerated static pile composting for about one year

�  Simple indigenous systems were designed, often using

unused material lying around in the compost plant �  Results were quite encouraging – reduced odour and

reduced time (by 2 weeks) for composting �  Aeration was optimised

�  This simplified aerated static pile system was found to be better than the aerobic windrow with weekly turning

�  Our compost quality standards are quite stringent

�  In spite of rules, segregation of MSW at source is not happening effectively, mainly because the ULBs are not able to make adequate arrangement for supporting segregation at source followed by segregated collection, transportation and taking the different components to the respective recycling facilities

�  Compost is used seasonally according to crops, necessitating warehousing

�  Pricing of FCO 2009 compliant compost is the biggest challenge

�  Result – thousands of tons of compost accumulated in plants

Conclusion

�  Paucity of land and difficulty in selling compost is tilting the scale in favour of thermal WtE

�  The Government of India has made a policy for supporting

sale of compost made from MSW (INR 1500 per ton compost) but disbursement of the money to a large number of beneficiary is a big challenge

�  The Central Electricity Regulatory Authority has revised the

power tariff quite favourably, which has become an added incentive to go for thermal WtE

�  However, biomethanation of food waste should also be explored in Delhi (200 TPD MSW based biomethanation plant operational at Sholapur in Maharashtra for past 2 years)

�  Appropriate management of C&D waste is crucial for compost quality as well as for boilers of thermal WtE

�  C&D Waste represents a large amount of waste disposal in the landfills

�  So far there are four commercially operating plants in India

�  Crushed and size-graded products:

•  GSB •  Brick pozzolana •  Recycled concrete / stone / tile aggregate of different sizes •  Recycled manufactured sand – mix of coarse, medium and fine

�  Mixed and moulded products:

•  Ready mix concrete (RMC) •  Kerb stones •  Paving blocks and tiles •  Bricks (solid, hollow)

These would be used for non-structural purposes:

•  Kerb stones (normally these do not have load bearing role).

•  Paving blocks and drain covers (pedestrian areas

and gardens). •  Cold moulded bricks (for non load bearing

structures such as, wall between RCC columns, small to medium height fencing walls, partition walls without additional load etc.).

Conclusion

�  Choice of technology / system would depend on quantity and characteristics of MSW, available site (size, neighbourhood, sensitivity), finance / fund available for capex and opex and management

�  For decentralized systems often paid employment for the plant is not affordable unless voluntary labour and management is at hand on a long term basis

�  In India and certainly in Delhi, availability and cost of land is the crucial factor, more so because site for waste management was not allocated in the master plans

�  Paucity of land and difficulty in selling compost is tilting the scale in favour of thermal WtE

�  The Government of India has made a policy for supporting

sale of compost made from MSW (INR 1500 per ton compost) but disbursement of the money to a large number of beneficiary is a big challenge

�  The Central Electricity Regulatory Authority has revised the

power tariff quite favourably, which has become an added incentive to go for thermal WtE

�  However, biomethanation of food waste should also be explored in Delhi (200 TPD MSW based biomethanation plant operational at Sholapur in Maharashtra for past 2 years)