Solid Waste Management - Public Health Notes

WHAT DO YOU MEAN BY SOLID WASTE MANAGEMENT?

Solid waste are any unwanted and useless solid materials generated from different domestic, trade, commercial, agricultural and industrial activities
It refers to any garbage, rubbish, sludge and other rejected solid and semi-solid materials obtained from different industrial, commercial, household or other activities.
These are non-liquid and non-gaseous wastes (durable goods, non-durable goods, containers and packaging, food scraps, yard trimmings, miscellaneous inorganic wastes, construction waste etc.)
The term solid waste usually includes:
Garbage: Includes food waste and other degradable organic wastes
Rubbish: Includes combustible and non-combustible solid wastes, except food waste
Refuse: Includes both garbage and rubbish
Litters: Includes paper bits, discarded wrappings, bottles etc.

DIFFERENT SOURCES OF SOLID WASTE:

Domestic/Household: Ash, rubbish, garbage,etc
Industrial: Wide variety from inert to highly toxic and explosives.
Street/ Market: Rubbish, paper, droppings, Putrid vegetables,etc.
Stable waste: From stables, animals
Hospital waste: cottons, bandages, medicine containers, glass, plastics,etc.

TYPES OF SOLID WASTE:

Depending on the source of waste, solid wastes can be mainly divided into three categories. They are

Municipal solid waste: It excludes industrial hazardous wastes but mainly includes:
Domestic waste
Commercial waste
Community waste
Construction waste
Institutional waste
Industrial solid waste: Also known as hazardous waste as it may include toxic substances
Biomedical waste/hospital waste: Discarded medicines, chemical substances, disposable syringes, swabs, bandages etc.

NEW HIERARCHY FOR SOLID WASTE MANAGEMENT:

Advanced approach for solid waste management is based on the principle of “waste hierarchy”. It can be understood from the figure given below:

TREATMENT FOR SOLID WASTE MANAGEMENT:

1.	Thermal Treatment: Thermal waste treatment refers to the processes that use heat to treat waste materials. Following are some of the most commonly used thermal waste treatment techniques:
a.	Incineration: – Most common waste treatment involves the combustion of waste material in the presence of oxygen. – The combustion process converts wastes into ash, flue, gas, water vapor, and carbon dioxide. – This thermal treatment method is commonly used as a means of recovering energy for electricity or heating.
b.	Gasification and Pyrolysis: – Done by decomposing organic waste materials by exposing waste to low amounts of oxygen and very high temperature. – Pyrolysis uses absolutely no oxygen – Gasification allows a very low amount of oxygen in the process
2.	Dumps and Landfills: It mainly includes three methods for waste management. They are:
a.	Sanitary landfills: – Provide the most commonly used waste disposal solution. – The landfill area can be comprised of clay soil which is quite resistant to hazardous wastes or is characterized by an absence of surface water bodies or a low water table, preventing the risk of water pollution. – The use of sanitary landfills presents the least health and environmental risk, but the cost of establishing such landfills is comparatively higher than other waste disposal methods.
b.	Controlled dumps: – These dumps comply with many of the requirements for being a sanitary landfill but may lack one or two. – Such dumps may have a well-planned capacity but no cell-planning.
c.	Bioreactor landfills: – These landfills use superior microbiological processes to speed up waste decomposition. – The controlling feature is the continuous addition of liquid to sustain optimal moisture for microbial digestion where the liquid is added by re-circulating the landfill leachate.

INTEGRATED MANAGEMENT OF SOLID WASTE:

Integrated Solid Waste Management (ISWM) is a comprehensive waste collection, treatment, recovery and disposal method that aims to provide environmental sustainability, economic affordability and social acceptance for any specific region.
Integrated solid waste management is therefore the process of optimizing the waste management system as a whole with application of a variety of suitable technologies.
It includes technical as well as managerial aspects of solid waste management.
Integrated solid waste management seeks to integrate various aspects of SWM by involving all stakeholders to optimize all the elements of the waste management system as a whole.
Integrated solid waste management is intended to help guide decisions about the generation of wastes, recycling of materials, and ultimate disposal of waste residues.

Technical aspects of integrated solid waste management include the following activities:

Waste handling and storage at source
Waste reduction
Waste separation
Street sweeping
Effective waste collection system
Waste transfer
Primary and secondary transportation
Recycled product manufacturing and marketing
Waste treatment
Sanitary landfilling
Hazardous waste management
Special waste (construction debris, bulky waste etc)
Remediation of polluted sites

Managerial aspects of ISWM include the following activities

Formulation and implementation of policies
Strategic and operational planning
Community mobilization
Public education
Private sector participation
Dispute resolution
Enactment of legislation and standards
Enforcement of regulations
Monitoring and evaluation
Organizational development
Human resource management and capacity building
Cost reduction and revenue generation
Management of information and communication

Source Reduction:

Not using unnecessary materials. For example: we can avoid using some packaging materials (or use less).
Using more durable alternative for example we can use a single canvas bag for multiple times instead of using plastic bags.
Reusing the same material for example soft drink bottles are reused to fill same product, it minimize new product cost as well burden to manage waste.
Onsite mulching and composting: Garbage (food waste) and agricultural residue are raw materials needed to prepare compost/soil conditioner and can be utilized in every house. So it must not be collected by municipality. If this principle can be utilized, more than half waste to be collected will be reduced.

Recycling

Recyclable wastes are collected from waste stream and processed in industry.
Using recycled material is a good practice to reduce environmental burden.

Treatment and Transformation

Thermal treatment like combustion with energy recovery and biological treatment like composting

Land Filling

Sanitary landfill: sealing and suppressing the wastes for decomposition.

IMPORTANCE OF SOLID WASTE MANAGEMENT:

Unsanitary conditions due to accumulation of the Solid wastes
Epidemic outbreaks
Diseases; Cholera, Diarrhoea, Plague, Dysentery, Jaundice, GI infections, etc.
Decomposition and putrefaction may occur
Intolerable odours.
Waterborne diseases such as gastro and cholera can form when an area of water is contaminated with waste, having an effective waste management plan greatly reduces the risk of the spread of disease.

References and for more information:

https://www.britannica.com/technology/solid-waste-management

https://www.google.com.np/search?q=importance+of+solid+waste+management+pdf&sa=X&ved=0ahUKEwjd_Ly9vcHcAhUO7mEKHfTcCO4Q1QII5wEoAQ&biw=1366&bih=635

https://www.conserve-energy-future.com/sources-effects-methods-of-solid-waste-management.php

https://www.adb.org/sites/default/files/publication/30366/solid-waste-

https://www.adb.org/publications/solid-waste-management-nepal-current-status-and-policy-recommendations

http://edugreen.teri.res.in/explore/solwaste/types.htm

https://www.linkedin.com/pulse/reason-why-solid-waste-management-important-your-raine-xiong/

https://www.linkedin.com/pulse/importance-waste-management-recycling-dee-mohammed/

http://www.toxfree.com.au/importance-solid-waste-management-plan/

https://www.cleantechloops.com/significance-swm/

https://www.quora.com/What-is-the-importance-of-solid-waste-management-1