The Performance and Potential of the Municipal Solid Waste Compost Plants in Batticaloa

(Technical Assessment)

N. Jayathilake

S. Fernando

Structure of the presentation

• Municipal solid waste management in Sri Lanka & Batticaloa

• Compost plants assessment

• Options for Nutrient enrichment and value addition of compost

Solid Waste Management - Sri Lanka

tonnes/dayTotal waste Generation 6,400 t Waste collection 2,700 t (42%)Organic waste to compost 400 tWaste disposal 2,300 t

Moisture content 70 – 80% HIGHCalorific Value 600 – 1000 kcal/kg LOW

(Bandara, 2008)

Solid Waste Management - BatticaloaCollection and Segregation

LA/ Compost plantSW collected

(T/day)segregated waste collected (T/day)

Batticaloa MC (BMC) 52.5 12

Kattankudy UC (KUC) 18.5 12

Kaluthavalai PS (MSEP-PS) 7.7 6

Arayampathy PS (MP-PS) 5.5 4.5

0.0

10.0

20.0

30.0

40.0

50.0

60.0

Batticaloa MC Kattankudy UC Manmunai South(Kaluthavalai) PS

Arayampathy PS

Was

te c

olle

cted

(T/

day

)

LA

Present level of source segregation

SW collected (T/day)

segregated waste collected (T/day)

Local Authority Waste

Collection (T/day)

Amount To compost plant

(T/day)

% of SW composted

Amount to landfill (T/day)

% disposed at landfill

BMC 52.5 2.6 5% 49.7 95%

KUC 18.5 4 22% 14.5 78%

MSEP-PS 7.7 1 13% 6.7 86%

MP-PS 5.5 1.2 22% 4.3 77%

Solid Waste Management - BatticaloaTreatment and Disposal

0 10 20 30 40 50 60

Batticaloa MC

Kattankudy UC

Kaluthavalai PS

Arayampathy PS

Waste Treatment and Disposal

SW composted (T/day) Total waste disposed at dump site (T/day)

Operating level of compost plants

Compost plant

Design

capacity

(T/day)

Theoretically

compostable

potential

amount

(T/day)

Actual

amount of

SW

composted

Operating

level

BMC 12 7.2 2.6 36%

KUC 12 7.2 4.0 55%

MSEP-PS 7 4.2 1.0 24%

MP-PS 7 4.2 1.2 28%

In general most of the compost plants in Sri Lanka operate at an average efficiency of 37%.

Compost Plants Assessment

Composting Process

Waste preparation

Windrow construction

Turning and watering

Curing

Value addition

Waste preparation

Waste PreparationWaste Sources

Source of waste

No. of units

BMC KUC MSEP-PS MP-PS

i. Domestic ( no. of households) 23,721 17,238 14,500 4,280

ii. Market 5 3 6 2

iii. Slaughter house 1 1 - 1

iv. Hotels/ restaurants 55 119 34 3

v. Hospital 3 1 2 1

vi. Commercial /Institutional 44 33 15 35

vii. Food processing industries - - - -

Waste inputQty of segregated waste (T/day)

BMC KUC MSEP-PS MP-PS

Food & Market Waste 1 2 1 1

Bulky Green waste 9 6 3 3

Agricultural Waste - 1.5 0.5

Fecal Sludge - - - -

Any other (Banana waste) 2 2.5

Total (T/day) 12 12 4 4.5

Type of input waste (segregated)

Alternative OptionsInput Type Animal excreta (that includes dead livestock and manure)

Food waste (household/hotels/markets)

Fresh Bio-solids

Municipal Green

Dry waste (hay, grass, sawdust)

Hard dry waste (timber, tree branches)

Potential for composting

High

Low

Low pollution potential

Source Availability

Segregated Hotel

and Restaurant

waste

A large volume of waste already been collected, but segregation is poor

Lagoon Algae The lagoon covers a total area of approximately 135.5 km2. Therefore a large quantity of algae

may be available

Livestock waste There are large quantities of cows, buffaloes, goats and chicken farmed in Batticaloa

Fish Waste BMC, KUC, MP-PS- and MSEP-PS area produce 6300MT, 1348 MT, 3460 MT and 1320MT of fish

harvest respectively

Faecal sludge Large numbers of households. Commercial entities.

Glidiceria/Giniseria There are large spaces in plant premises that can be cultivated

Husk ash Paddy farming is the major agriculture activity in the region with a large area

Source: Department of Environment Affairs (2013) The national Organic Waste Composting Strategy, South Africa

Pollution potential of

waste sources

Windrow Construction

Particle size

• The best sized particles for composting are less than 2 inches (or 50 mm) in the largest dimension

• Shredding creates a greater surface area, which makes it more susceptible to bacterial activities or biodegradation. Large pieces of wood or leaves do not decompose quickly in a compost pile

• Insufficient oxygen in the center of a wood chunk or a wad of leaves does not permit rapid aerobic decomposition

Windrow size

LA/ Compost plant

Qauntityof one pile (t)

Size of one pile (L*W*H)

BMC 2.6 3m* 1.5m*2m

KUC 2.0 4m*2m* 2.5m

MSEP-PS 0.5 4m*2m* 2.5m

MP-PS 2.4 3m* 1.5m* 1.8m

The size of the windrow should be increased to provide higher temperatures in cold weather or decreased to keep the temperatures from becoming too high in warm weather.

From Pilisaru experience

Windrow LocationsCompost

plant

Buildings area

Unloading & sorting Pilling area Preparation & store

m2

BMC 330 864 50

KUC 54 547 330

MSEP-PS 135 420 14.4

MP-PS 36 412 7

• From experience from other compost projects in the country (Pilisaru project), open windrows during the initial stage has proven to be successful.

• Aged windrows should be moved to covered areas

Batticaloa compost plant

Kattankudy compost plant Arayampathy compost plant Kaluthavalai compost plant

Turning and watering

Turning & Watering

50-60% of the moisture content in piles should be maintained to allow accelerated microbial activities.

When the moisture content reaches 40% microbial activities decrease & cease at 20%. Microbial activities are reduced at moisture contents beyond 60% due to a low availability of oxygen.

Quick & easy onsite methods could be practiced for monitoring process parameters such as moisture, temperature and proxy indicators such as odour

Compost plant Process Parameter

Decomposition time

3 days 1 week 3 weeks 5 weeks 8 weeks

Batticaloa MC Moisture % <40% >60% - <40% <40%

Temperature oC >500C >500C >600C >600C >500C

Kattankudy UC Moisture % - <40% 50% <40% <30%

Temperature oC - >500C 400C 40-450C 300C

Manmunai South

(Kaluthavalai) PS

Moisture % - <40% 60% 40% <40%

Temperature oC - >500C >500C >500C 300C

Arayampathy PS

Moisture % <30% <40% 60% 40% 30%

Temperature oC - 500C 500C 600C 500C

Temp. Change and Pathogen Die Off

TurningPlant 1st turning after

Turning frequency

Decomposition

period

Batticaloa MC 10 days once in 10 days 10 weeks

Kattankudy UC

14 days once in 14 days (short term)/

once in 21 days (long term) 10 weeks

Manmunai South

(Kaluthavalai) PS

14 days

once in 14 days 10 weeks

Arayampathy PS

10 days Once in 10 days (short term)/

once in 15 days (long term) 10 weeks

Windrow turning should be decided by the pile temperature rather than by fixed turning intervals.

During the initial stage, high temperatures demand frequent turning and later in the process reduced temperatures demand low frequency in turning.

Curing

CuringLA/ Compost plant

Decomposition period

Curing period

Batticaloa MC 10 weeks 2 weeks

Kattankudy UC 10 weeks 3 weeks

Manmunai South (Kaluthavalai) PS 10 weeks 3 weeks

Arayampathy PS 10 weeks 2 weeks

To lower the phytotoxicity, improve the pH, lower the C/N ratio and stable product

Parent feedstock quality, the manner and the degree of stability of the decomposing organic matter will influence the time required for curing to stabilize the compost

Curing time can range from 21 days to months. Many researchers recommend at least a month

Garilio et al (2010) confirms the germination bioassay using lettuce seed was sensitive

enough and was able to identify the presence of phytotoxic compounds in compost

Improvements to Compost

Consumer Need Frequency %

Increase the nutrient value 71 59%

Reduce the sand content 35 29%

Reduce the inert content 22 18%

Reduce odour 5 4%

Increase the particle size 3 2%

Reduce the price 3 2%

Proper labelling 3 2%

Top three consumer needs are about improving quality

Add moisture up to 25% while measuring it with a moisture meter

Add binding agents as per the concentration as weight

Sieve the co-compost with

5 mm mesh (Manually or

Mechanically)

Check initial moisture of

the co-compost

Thoroughly mix the mixture to get it a homogeneous mixture

Feed into the pelletizer

and taken out the pellets

Dry pellets under sun for 5-6 hours

Value addition

Co-composting & Pelletizing

Co-Composting

Safe Organic Fertilizer

Septage treatment ( co-composting)

MSW

Septage

Compost

Site

Drying beds

Transporting

Organic

Waste

Sorting

DFS

Dewatering

Drying

PilePilePileCo-

compost

SievingMaturing Turning

TurningWatering

Incorporation

Value addition using mineral fertilizer

So far agronomic trials show that 5% of the N content is adequate

Urea and Ammonium sulphate can be used as enrichment agents

Quality of compost

Kattankudy

UC

Batticaloa

MC

Manamnunai

south PS

(Kalutavalai)

Arayampathy

PS

Acceptable

range

pH 8.17 8.36 8.43 8.75 6.5-8.5

EC ds/M 2.80 1.68 0.8 0.68 0.5-3

P2O5 % 1.33 0.69 0.62 0.60 0.5-4

K2O% 2.13 3.05 1.52 1.85 0.5-3

Total N % 1.46 1.4 1.11 0.96 0.5-3

Organic C % 13.26 24.58 17.84 20.90 20-35

Sand % 12.19 29.8 45.22 40.85 <10

Moisture % 27.9 23 10.7 12 20-30

C:N - 17.6 16.1 21.8 20-30

Recommendations• Improve source segregation allowing high amount of short term

biodegradable waste supply at the plant. Eg: collecting waste from organic waste sources in large quantities, which can be found in segregated manner; i.e. market waste, food processing industry waste, etc

• Educating workers to practice quick and easy onsite methods for monitoring and maintaining process parameters such as moisture, temperature and proxy indicators such as odour

• Windrow size as per Pilisaru finding

• Facilitate undercover composting as necessary to avoid unfavorable conditions caused by extreme weather conditions

• Arranging regular knowledge transfer practices and training programmes for the working force

• Value addition with nutrient rich waste sources such as manures, fecal sludge, etc.

Thank you