Overview of Solid Waste Generation and Management Techniques(Report)

Report number: R1

A

REPORT

ON

OVERVIEW OF SOLID WASTE GENERATION AND MANAGEMENT TECHNIQUES

SUBMITTED TO

DR. ISHWOR BAJRACHARYA

DR. NAWARAJ BHATTARAI

DEPARTMENT OF MECHANICAL ENGINEERING

PULCHOWK CAMPUS

IOE, PULCHOWK

SUBMITTED BY

KUSHAL SHRESTHA

069-BME-622

DEPARTMENT OF MECHANICAL ENGINEERING

PULCHOWK CAMPUS

IOE, PULCHOWK

MARCH 25, 2016


TABLE OF CONTENTSTABLE OF FIGURES AND TABLES..................................................................................................II

LIST OF ABBREVIATIONS.................................................................................................................II

1 INTRODUCTION:..........................................................................................................................1

2 THEORY.........................................................................................................................................1

2.1 Aspects of SWM System.........................................................................................................1

2.2 Factors Affecting SWM...........................................................................................................3

3 CURRENT SCENARIO..................................................................................................................4

3.1 Waste Generation.....................................................................................................................4

3.2 Waste Management..................................................................................................................6

4 DISCUSSION AND CONCLUSIONS...........................................................................................7

5 REFERENCES................................................................................................................................8


TABLE OF FIGURES AND TABLES

Figure 1: Waste Generation.....................................................................................................................4Figure 2: Source of Waste in KMC (2004)..............................................................................................5Figure 3: Source of Waste in KMC (2009)..............................................................................................5Figure 4: Types of Solid Waste Disposal Method in Municipalities of Nepal........................................6

Table 1: Comparison of Source of Waste in KMC..................................................................................5

LIST OF ABBREVIATIONS

ADB : Asian Development Bank

KMC : Kathmandu Metropolitan City

LSMC : Lalitpur Sub- Metropolitan City

SWM : Solid Waste Management

II


1 INTRODUCTION:Solid waste is defined as all the solid and semisolid materials discarded by a communitye.g. garbage, food waste, etc.

Waste Generation encompasses all the activities in which waste, be it solid or semi-solid material, no longer has sufficient economic value for its possessor to retain it. Waste is generated in each step of production.

Waste Management refers to the control of waste generation, its storage, collection, transfer and transport, processing and disposal in a manner that is in accordance with the best principles of public health, economics, engineering, conservation, aesthetics, public attitude and other environmental considerations.

2 THEORY

2.1 Aspects of SWM SystemI. Storage:

Waste storage encompasses proper containers to store wastes and efficient transport of wastes without any spillage to transfer stations/ disposal sites.i. Containers:

- used for storage of wastes at the site of generation until they are collected.- desirable characteristics: low cost, size, weight, shape, resistance to corrosion, water tightness, strength and durability.- 100-200 m between each container (source: nptel)

ii. Collection Vehicles:- must be selected according to terrain, type and density of waste generation points, route and kind of materiale.g.: small scale, non-compactor trucks, and compactor

II. Collection:Includes the gathering of wastes and transporting of wastes to transfer stations and/or disposal sitesFactors:i. Collection points

ii. Collection frequencyiii. Storage containersiv. Collection crewv. Collection route

vi. Transfer station

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III. Transfer and Transport:The transport of waste after collection, from the collection sites to the processing area or dump site. It also includes the transport process from generation area up to the collection areaTransfer station is provided for separation of usable waste. This also serves as an intermediary between different collection sites and the common disposal site.

IV. Processing:Processing is done to achieve the best possible benefit from every functional element of the SWM system. The wastes that are considered suitable for further use, are processed to derive maximum economical value from themProcessing can also be done to facilitate disposal.Various methods of processing are:i. Volume reduction or compaction

ii. Size reduction or shreddingiii. Component separationiv. Drying

V. Recovery and Recycling:Recycling is the process of utilizing the waste as raw material for a new product.It can help in reducing the amount of waste. It is done to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, energy usage, air pollution (from incineration) and water pollution (from landfilling) by decreasing the need for "conventional" waste disposal and lowering greenhouse gas emissions compared to plastic production.Recovery is the process of extracting the usable part of waste in the form of energy, or material

VI. Disposal:Disposal is the final element in all the SWM systems. All types of waste, even after treatment needs to be disposedVarious disposal techniques are:i. Uncontrolled dumping or non-engineered disposal

ii. Sanitary landfilliii. Compostingiv. Incinerationv. Gasification

vi. Refuse-derived fuel (RDF)vii. Pyrolysis

The disposal techniques are selected on the basis of the following criteria:i. Technical

ii. Institutionaliii. Financialiv. Socialv. Environmental

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2.2 Factors Affecting SWMI. Quantity and Characteristics of Wastes:

One measure of characteristic of waste is its density. A high density reflects a relatively high proportion of organic matter and moisture and lower levels of recycling.

II. Climate and Seasonal Variations:Higher temperature and humidity means faster decomposition. So frequency of waste collection needs to be higher in high temperature and humid climates.

III. Physical Characteristics of Urban Area:The physical characteristics of an area like the accessibility of roads determine the appropriate mode of method of SWM. The nature and size of roads for example will determine the nature of collection; hand carriage in narrow road and large trucks in main roads.

IV. Cultural Constrains:There is a tradition of caste for labor to be drawn from a certain sections of population. Social norms may override the rational solutions. People of so called higher class hesitate to work in the field of SWM.

V. Management And Technical Resources:The resources available at the disposal of the governing body such as available manpower, budget and other resources like dustbins, collector trucks determine the SWM system employed.

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3 CURRENT SCENARIO

3.1 Waste Generation According to ADB, a survey conducted in 2012, in all 58 municipalities found that

317 grams per capita per day of waste was generated. According to the findings of the Environment Statistics of Nepal 2013 published by

the Central Bureau of Statistics (CBS) for the fiscal year 2012-2013: Total amount of wastes generated by the 58 municipalities was around 670

metric tons per day KMC alone generated 457 metric tons of solid waste per day

Of which, 63.2 percent is organic while plastic, paper, and glass constitute 10.8, 9 and 5.4 percent of the solid waste respectively

After Kathmandu, the top five solid waste generators among the 58 municipalities are: Pokhara, Lalitpur, Kalaiya, Dharan and Butwal, which generate 83, 65, 52.1, 50.2 and 47 metric tons of solid waste per day respectively

Lowest quantities were generated at Waling, Dipayal, Triyuga, Ramgram and Baglung

The data for fiscal year 2006-2007 for KMC was 29.9 metric tons per day and for fiscal year 2009-2010 was 318.4 tons per day

Figure 1: Waste Generation

(Source: ENVIRONMENT STATISTICS OF NEPAL 2013)

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Household63%Commercial

9%

Institutional9%

Street9%

From VDCs9%

2004

Figure 2: Source of Waste in KMC (2004)(Source: ENVIRONMENT STATISTICS OF NEPAL 2013)

Household69%

Commercial10%

Street10%

From VDCs10%

2012

Figure 3: Source of Waste in KMC (2009)(Source: ENVIRONMENT STATISTICS OF NEPAL 2013)

Year HouseholdWaste

CommercialWaste

InstitutionalWaste

StreetWaste

Wastefrom VDCs

Total

2004 200 30 30 30 30 3202012 339 51 0 51 51 492

Table 1: Comparison of Source of Waste in KMC(Source: ENVIRONMENT STATISTICS OF NEPAL 2013)

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3.2 Waste Management 30% of surveyed household in municipalities separate waste Collection efficiency ranges from 70 to 90 percent, for KMC 85% Collection modes: Container service, door-to-door collection, and roadside pickup

from open piles or containers Transport modes:

rickshaws, carts for primary collection Tractor for secondary collection Dump trucks for transport to disposal sites

Transfer sites are not available in major municipalities except KMC, Lalitpur, and Madhyapur Thimi; transfer station for KMC and LSMC : Teku

For Kathmandu and Lalitpur, a sanitary landfill site at Sisdol, Okharpauwa was constructed operated as a sanitary landfill site in the early stage of operation, although currently it is not operated as a sanitary landfill site.

The household waste composition survey revealed that more than 25% of household waste and a much higher proportion of institutional and commercial waste could be either reused or recycled

No formal system for recycling exists Informal and source recycling is present(scrap dealers) Composting is done in 30% of surveyed household

Figure 4: Types of Solid Waste Disposal Method in Municipalities of Nepal

(Source: Asian Development Bank)

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4 DISCUSSION AND CONCLUSIONSThe current methods of waste disposal are inefficient. The open dumping technique which is very common can make the waste a disease vector which transmits various types of disease and also shelter pests and rodents. This can also cause various types of pollution like air, soil, water, etc. The lack of recovery and recycling means a large volume of waste needs to be disposed and some potentially useful material is also lost in the waste. The current disposal technique of landfill site has also failed. The landfill site has been filled past its capacity and has been extended for temporary relief but the problem is set to persist if other concrete efforts are not made.

So a better system is required. It should incline with the 3R (reduce, reuse, recycle) principle to reduce generation and aid proper management of waste. Also to reduce the waste that is produced, segregation followed by proper disposal techniques tailed to each component should be applied, e.g.: bio digestion for organic waste, incineration for inorganic waste. The system should however not contribute to further pollution (of another kind) e.g. incineration can cause air pollution. So, proper designed systems with proper pollution control measure must be employed.

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5 REFERENCESENVIRONMENT STATISTICS OF NEPAL2013. Kathmandu: Central Bureau of Statistics , 2013.

Nptel:: Environmental Science- Municipal Solid Waste Management. 20 June 2012. <www.nptel.ac.in>.

Recycling. n.d. <https://en.wikipedia.org/wiki/Recycling>.

Solid Waste Management in Nepal: Current Status and Policy Recommendations. Mandaluyong City: Asian Development Bank, 2013.

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Overview of Solid Waste Generation and Management Techniques(Report)