The special case of primary collection

CONTENTS

1.1 Introduction................................................................................................... 1

1.2 Municipal waste generation and characterization.......................................... 1

1.3 Waste collection and transport....................................................................... 3

1.3.1 Optimization of waste collection and transport................................. 4

1.3.2 The special case of primary collection................................................ 4

1.4 Recycling municipal waste............................................................................. 5

APPENDIX/APPENDICES

1 Appendix on one page

2 Appendix on several pages

Introduction

Municipal waste generation and characterization

The map below clearly shows the dependence between average income per capita and the average amount of solid waste per year per person.

Рic 1: Higher the income-more rate of waste generation

Waste generation rate is influenced by:

· Lifestyle

· Urbanization

· Income

This graph predicts the waste generation growth rate in different country income groups. The highest gain is forecasted in lower middle income country group due to the expected increase of population.

Рic 2 Bigger the population-more waste is produced

The fractions of solid waste differs for country income groups.

The pie chart demonstrates the decreasing of the organic component and increasing of packaging (paper and plastic) waste respectively country income growth. Nevertheless, the waste compostion depends on the location , due to differences in lifestyle and habits.

Because of the various composition of solid waste in country income groups the waste properties are different too.

Moisture content and density are higher in low-income countries due to the greater amount of organic waste.

According to the folmulae from the slide the bigger the amount of plastic and rubber the greater is the calorific value.

How to measure properties of waste?

· Divide into subareas (e.g. income)

· Decide on properties to measure

· Random sampling

· Full week sampling-weekly variations

· Multi seasonal sampling – seasonal variations

Waste collection and transport

The main problem of waste management is the lack of money.

Solutions (optimally if done both):

· Decrease the cost

· Increase tax revenues

The most expensive part of waste management are collection and transport (payment for workers and trucks).

Measures to decrease the cost of collection and transportation:

· Loading in a shorter time

· Volume as great as possible (influences time and fuel consumption)

· Unloading as short as possible

· Use containers with large capacity (reduce the truck loading time)

· Reduce number of collection points (shorten time and fuel consumption)

· Implement the transfer station

Optimization of waste collection and transport

The special case of primary collection

Solutions for waste collection in difficult access areas is a split of waste collection into 2 steps: primary collection, which provides services in the neighborhood with smaller vehicles or more simple technology; then the transport of this collected waste to a collection point, where it is stored in larger containers, and then secondary collection, which removes this waste regularly for transport to the treatment or disposal facility.

Recycling municipal waste

This paragraph is mainly focused on recycling of paper and cardboard, glass, plastics and metal.

Paper:

Types

· Post-consuming paper – newspaper and magazines

· Corrugated cardboard – obtained from commerce

· High grade paper – comes from businesses

Processing

Sorting and removing impurities èGrinding (mechanical or chemical) èProducing a slurry èBleaching(optional) è Pressing and drying

The cycling of paper is never close the loop fully due to:

· Loss of the paper by storage

· Shortening of fibers (recycled paper should weigh 5 to 15% more per area, or should be mixed with virgin pulp).

Increase: Reduce:

Energy consumption Electricity consumption

Residues and emissions Wood consumption

Glass:

Types

· soda-lime glass is used for bottles, jars, drinking glasses (colors: clear, green and brown) – recycled by re-melting, shouldn’t mix with other 2 glass fractions

· crystal glass, which is used for high quality drinking glasses, vases and art

· borosilicate glass, also called Pyrex, which is used for laboratory glassware

Processing: reuse (ideal)!

If recycled there is 2 possible ways:

· Cullet is re-melted and used to produce new bottles

· Substitute of building materials

The table below shows that recycling of glass has environmental benefits (the column comparison demonstrates the reducing of expenditure resources).

Plastic:

Рic 3 Types of plastic (per their names)

Problems of recycling:

1. Contains plenty of contaminants and impurities (bio waste)

2. Different plastic types are often mixed together

Plastic recovery:

1.Energy recovery (heat and electricity)

2.Material recovery (chemical or mechanical)

Except increase of solid residues, total inputs for producing plastic from recycled plastic is much lower than production of virgin plastic.

Metal:

Types

· Metal scrap

· End of life vehicles

· Post-consumer metals

Recycling:

Removing impurities è re-melting in furnaceè generating the new products

This table is clearly shows the environmental benefits of metal recycling (1/3 of aluminum and steel products are generated from recycled material)

Further information: