Characteristics on Waste Disposing Behavior and Density Distribution of Combustible Waste Bag

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Characteristics on Waste Disposing Behavior and
Density Distribution of Combustible Waste Bag
?Shinya Suzuki, Masachika Yamashita, Ayako
Tachifuji, Yasushi Matsufuji Department of
Civil Engineering, Fukuoka University 8-19-1
Nanakuma, Johnan-ku, Fukuoka, 814-0180
Japan E-mail ssuzuki_at_fukuoka-u.ac.jp
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions1-1
Background

• Increasing number of municipalities
• begun charge for waste collection
• - to realize a recycling-oriented society
• - facilitate to give economical incentive
• for waste reduction and recycling
• - in many cases, Pay-as-you-throw system
• - by using specified waste bag
• - facilitate to gather charge effectively

2) Some municipalities convert way of waste
collection - from bring collection method
(station collection) - to curbside
collection method (door to door collection)
- specify common waste collection point for
multiple households
- Each household dispose of waste in front of
entrance of housing - clarify waste generators
responsibility, stimulate waste separation
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions1-2
Objective
Introduction of Pay-as-you-throw system -
stimulate through waste separation and
recycling - has effect on waste reduction How
about influence on waste generation and
collection ?
For better management on waste collection, To
clarify characteristics on waste disposing
behavior - under door to door collection
method - by using specified waste bag -
How often ? - How many capacities ? - How
many bags ?
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions2-1 Study
Area Fukuoka city, Japan
In Fukuoka city, for municipal combustible
waste, - Pay-as-you-throw system - door to
door collection - 15 litters (15 yen/bag) -
twice a week in night time - 30 litters (30
yen/bag) - 45 litters (45 yen/bag)
One district in Fukuoka city - 1,664
peoples - 673 households - 0.17 km2 - 9,800
people/km2
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions2-2
Analytical Methods
50 sample households - with a variety of
household size - using specified collection
point - identify relationship between disposed
waste bag and waste generator
Actual measurement survey on amount of waste -
to clarify actual status on waste disposing - on
March 7th 2006, March 10th, March 14th, March
17th, continuously
- enable to confirm retention time in each waste
bag - Disposing frequency - Number of waste
bag - Capacity of waste bag - Weight of waste
bag
- Density of waste bag
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-1-1)
Actual Status on Disposing Pattern
Every time 27 households
16 patterns in 4-time collection

Only half of households did not always take waste
out ! - not have regularity for disposing
pattern of waste bag
3 times 12 households

2 times 7 households
- forgotten ? - purposely ?

1 time 1 household
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-1-2)
Summation of Waste Disposing Pattern
Relationship between disposing frequency and
profile of waste bag - 70 of household using
only 1 kind of waste bag (many household !) -
Even though household less than 3 times,
using 45 litters of bag, not 30 or 15 litters
of bag
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-1-3)
Number of Waste Bag disposed
Few households actually forgot taking waste
out Many households kept from disposing for
adjustment of amount of waste ??
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-2-1)
Density Distribution of Waste Bag
Conventional apparent density (at pit
incineration plant) - Mean value 0.20 (kg/L)
Density of waste bag (at each collection
point) - Wide distribution - Mode value 0.08 -
0.10 (kg/L)
Cumulative frequency - indicate 100 near 0.20
(kg/L)
In fact, waste bag can be fulfilled with 0.20
(kg/L) of waste, but actually, Many households
feel waste bag full around 0.08 0.10 (kg/L)
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-2-2)
Density simultaneously disposed from each
collection day
Left part already entered waste full into 1st
bag before collection day Right part a large
amount of waste at each collection day, could
not enter waste into 1 bag at the same time
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions3-3-1)
Estimated Way of Using Waste Bag
20
12
5
70
25
5
5
15
5
8
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions4-1
Conclusions
Actual status on waste disposing behavior and
density distribution of waste bag
Only half of households did not always take waste
bag out
High proportion of households used 45 litters of
waste bag - Many households reduced waste
disposing frequency - not from bothering or
forgetting - but from adjustment of amount of
waste - decided size of waste bag in advance
- based on amount grasped from long time
experience
We newly introduced density of waste bag - to
confirm waste disposing behavior - 0.10 0.12
(kg/L) as full for many households
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1. Introduction 2. Materials and Methods 3.
Results and Discussion 4. Conclusions4-2
Conclusions
Capacity of waste bag decided by each
municipality - influence waste disposing
behavior
Important for municipalities to set up capacity
of waste bag - considering amount of waste
disposed - considering not apparent density but
density of waste bag - Especially we must take
care of introducing specified bag - under
Pay-as-you-throw system
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Thank you very much for your attention !