Waste is defined as any unwanted or unusable substance that is discarded after primary use. Wastes are normally generated as a result of human and animal activities. Urbanization and rapid advancements in industrialization has led to an increase in the production and consumption processes resulting in the generation of wastes from various sectors that include agricultural, commercial, domestic, industrial, institutional, social and from community activities. Over time, these waste accumulate and can have real impacts on the health and the environment. Waste management is intended to reduce adverse effects of waste on health, the environment or aesthetics. So to carry out efficient management of wastes, knowledge about the source of wastes, its types and classification must be known.

   

Classification of Waste

 

Wastes are commonly classified based on the physical state as Solid Wastes, Liquid Wastes and Gaseous Wastes.

 

1. Solid Wastes: Solid wastes are any discarded or abandoned materials that can be solid, liquid, semi-solid or containerized gaseous material discarded by the human society. These include urban wastes, agricultural wastes, biomedical wastes and radioactive wastes. The term refuse is also used for solid wastes. Examples of solid wastes include waste tires, septage, scrap metal, latex paints, furniture and toys, garbage, appliances and vehicles, oil and anti-freeze, empty aerosol cans, paint cans and compressed gas cylinders, construction and demolition debris, asbestos, plastics, styrofoam containers, bottles etc.

 

2. Liquid Wastes: Liquid wastes can be defined as liquids/fluids that are generated from washing, flushing or manufacturing processes of the industries. They are also called as sewage. The most common practice of disposing liquid waste is to discharge it in ground or rivers and other water bodies without treatment. Examples: domestic washings, chemicals, oils, waste water from ponds, Wastewater from manufacturing industries, manure, waste oil, fats, oils or grease (FOG), used oil, and hazardous household liquids.

 

3. Gaseous Wastes: It is a waste product released in the form of gases from automobiles, factories, industries, burning of fossil fuels etc and get mixed in the atmosphere. These gases include carbon monoxide, carbon dioxide, sulphur dioxide, nitrogen dioxide, ozone and methane etc.

 

Classification of Solid Waste
 

          It is mandatory to classify solid wastes into groups that pose similar risks to the environment and human health for safe disposal. According to the modern systems of waste management, solid wastes are classified based on their source, type, properties and its effect on human health and environment.

 

Source Based Classification
 

          Wastes are produced from different sources and are categorized as follows:

 

1. Municipal Solid Waste:

 

                  Municipal solid waste commonly referred to as trash, garbage or refuse comprises of street wastes, dead animals, market wastes, abandoned vehicles, household garbage, rubbish, construction and demolition debris, sanitation residue, packaging materials, trade refuges etc. They are collected from residential houses, markets, streets and other places mostly from urban areas and disposed of by municipal bodies. The proportion of different constituents of municipal wastes vary from place to place and season to season depending on the food habits, life style, standard of living and extent of commercial and industrial activities in the area. Municipal solid wastes are further categorized based on their physical, chemical and biological properties.     
 

• Solid Waste Management 

 

2. Industrial Waste

 

                  Wastes generated during industrial activities such as manufacturing and processing involved in chemical plants, paint industry, cement factories, metallurgical plants, thermal power plants, petroleum, coal, gas, sanitary, textile, food processing and paper industry are referred to as industrial wastes. Some examples of industrial wastes are chemical solvents, paints, sandpaper, paper products, industrial by-products, metals, and radioactive wastes. Industrial solid wastes are further classified as hazardous and non-hazardous wastes.

 

3. Institutional / Commercial Wastes

 

          Solid wastes originating from administrative, educational and public buildings such as offices, schools, colleges, hospitals, government centres, prisons and other commercial establishments like wholesale and retail stores, restaurants, hotels, markets, warehouses. Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes are the examples of industrial and commercial wastes.

  

4. Agricultural Waste

 

                  Agriculture wastes includes both natural (organic) and non-natural wastes generated through farming activities. These activities include but are not limited to dairy farming, horticulture, seed growing, livestock breeding, grazing land, market gardens, nursery plots, and even woodlands. Some of agricultural wastes include spoiled food grains, vegetables, animal and plant wastes, litter, pesticides, fertilizers etc. Other agricultural wastes are produced from agricultural products processing industries like sugarcane factories, tobacco processing units, slaughter houses, livestock, poultry etc. Agricultural wastes are mostly biodegradable but few wastes like pesticide and fertilizers are toxic. When discharged to the environment, agricultural wastes can be both beneficial and detrimental to living matter.

 

5. Biomedical Waste:

 

                  Wastes produced from hospitals, medical centres and nursing homes are called biomedical wastes. Hospital wastes are generated during diagnosis, treatment or immunisation of human beings/animals or in research activities in these fields or in the production/testing of biological. These wastes are highly infectious and may pose severe threat if not managed properly. Biomedical wastes may be solid or liquid wastes that includes discarded blood, sharps, soiled wastes, disposables, anatomical wastes, cultures, discarded medicines, chemical wastes etc.

   

Type Based Classification

 

1. Garbage: Garbage wastes mean and include animal and vegetable wastes generated from kitchen, cooking, serving of foods, slaughter houses, market refuse. These wastes contain putrescible organic matter which produces strong odour. They attract rats, vermins, flies and other insects and so they requires immediate attention in handling and disposal.

 

2. Rubbish: Solid wastes arising as a result of households, commercial and institutional activities excluding garbage and ashes is termed as rubbish. They are categorized into combustible and non-combustible wastes. Combustible wastes consists of all rubbish and refuse that can be incinerated to flames at 1400-1500⁰F which includes leaves, plants, clothes, paper, leather, rubber, grasses. Non-combustible wastes are characterized as wastes that cannot be incinerated to flames at 1400-1500⁰F and that includes glass, metals, plastic materials, stones, auto parts etc.

 

3. Bulk Waste: Bulky household wastes consists of household furniture; appliances such as stoves, washing machines and refrigerators; mattresses and springs, rugs, TV sets, water heaters, tires, lawn mowers, auto parts, tree and brush debris etc. Commercial bulky wastes include packaging and containers such as cardboard, wood boxes, fiber, plastic and steel drums, loose and bundled paper, bundles of textiles and plastics, wires, furniture and equipment etc. Industrial bulky waste includes crates, cartons; steel, fiber and plastic drums; bales and rolls of paper, plastics, and textiles; miscellaneous metal items etc.

 

4. Ashes: Ashes are defined as fine powdery residues, cinders and clinkers arising from the burning of wood, coal, charcoal, coke and other combustible materials during cooking and heating in houses, institutions and outer industrial establishments.

 

5. Street Wastes: Wastes comprising of leaves, dirt, dust litter, paper, plastics and other vegetable matter collected from streets, walkways, alleys, parks, beaches and vacant lots are termed as street wastes.

 

6. Dead Animals: Animals that die naturally or accidentally comprises of dead animal wastes. They are categorized as small animals such as cats, dogs, rats, rabbits, poultry and large animals like horses, cows, goats, Sheep etc. However, animal carcasses and animal parts from slaughterhouses are excluded from dead animal wastes and considered as industrial wastes. These dead animal wastes are putrescible and attract flies and other vermin posing severe health risk to the environment. Hence they must be collected and disposed off promptly.

 

7. Construction and Demolition Wastes: Construction and demolition wastes are the waste materials generated in large amounts during the construction, refurbishment, repair and demolition of houses, commercial buildings, roads and other structures. They consist of earth, stones, concrete, bricks, lumber, steel, roofing materials, plumbing materials, heating systems and electrical wires.

 

8. Sewage Wastes/Sludge: Settled solid components, residual or semi-solid materials that are discharged from sewage treatment plants and septic tanks are classified as sewage waste. The raw and the treated sewage consist of organic and inorganic fraction. The sewage wastes contains putrescible organic matter which may contain pathogens and so must be disposed off without delay.

 

9. Plastics: Plastic due to their versatile property of being light, durable, easy to mould and economical has invaded almost all sectors of the economy. Likewise, they are generated as wastes from almost all sectors that include agriculture, construction, consumer goods, household, health care, hotel and catering, packaging, telecommunications, air and travel industries. Some of the plastic wastes include carry bags, bottles, plates, spoons, glasses, gloves, boxes, syringes, catheter tubes, surgical items etc. Plastics due to its non-biodegradable nature are now considered a serious threat to the environmental and health.

 

10. Mining Wastes: Mining wastes are generated from extractive operations of mineral resources. They include materials such as topsoil, overburden and waste rock that must be removed to gain access to the mineral resource. Also, other waste material like slags, mine water, mine tailings, water treatment sludge and gaseous wastes etc are released during or after processing of mineral ores. Some of these wastes are inert and are not considered as threat to the environment. However, other fractions, generated by the non-ferrous metal mining industry contains large quantities of dangerous substances such as heavy metals. These metals and metal compounds after extraction and subsequent mineral processing, tend to become chemically more available resulting in the generation of acid or alkaline drainage. Therefore, mine wastes requires to be carefully characterized to prevent and minimize air, water, and soil contamination.

 

11. Radioactive Wastes: Radioactive wastes are hazardous, by-products of nuclear reactions. They pose severe threat to human life and environment. Radioactive wastes decays over time ranging from a few days for highly radioactive isotopes to millions of years for slightly radioactive ones. Hence, these wastes have to be isolated and confined at appropriate disposal facilities for it to completely decay. The sources of radioactive wastes are from mining of radioactive substances, atomic explosion, nuclear fuel cycle, nuclear weapons reprocessing, medical and industrial wastes etc.

 

Property based classification :

 

            Solid wastes are also classified based on their biological and chemical property.

 

1. Biodegradable / Organic Wastes: Biodegradable wastes are those that can be decomposed by the natural processes such as composting, aerobic/ anaerobic digestion and converted into the elemental form like carbon dioxide, methane, water or simple organic molecules. Some of the biodegradable wastes include municipal solid wastes (green waste, food waste, paper waste, biodegradable plastics, human and animal wastes, sewage, sludge, slaughter house wastes etc).

2. Non-biodegradable /Inorganic Wastes: Non-biodegradable wastes are those that cannot be decomposed and remain as such in the environment indefinitely. They are persistent and threaten to overwhelm landfills and create disposal problems creating environmental concern. As non-biodegradable wastes cannot be decomposed, recycling is the ideal option for managing it. Example of non-biodegradable wastes includes plastics, nuclear wastes, glass, rubber tyres, styrofoam, fiberglass and metals.

 

3. Hazardous Wastes: Hazardous waste is defined as chemical material that can no longer be used for its intended purpose and is known to be harmful or potentially harmful to plants, animals and human health or to the environment. Hazardous wastes may be in the form of solids, liquids, sludge’s or gases. In some cases, although the active agents may be liquid or gaseous, they are classified as solid waste because they are confined in solid containers. They are generated primarily by chemical production, manufacturing and other industrial activities. The hazardous waste materials may be toxic, reactive, ignitable, explosive, corrosive, infectious or radioactive. If improperly handled, they can cause substantial harm to human health and to the environment. So good management practice should ensure that hazardous wastes are collected, stored, transported and disposed off separately, to render them innocuous. Some of the important hazardous wastes are lead, mercury, cadmium, chromium, many drugs, leather, pesticides, dye, rubber, solvents, paints and effluents from different industries.

 

• Inventorisation of Hazardous Waste Kannur to Wayand | Part I | Part II

• Inventory of Hazardous Waste Generating Industries in Ernakulam,Idukki, Kottayam & Thrissur 2017 

• Inventory of Hazardous Waste Generating Industries in Thiruvananthapuram ,Kollam, Pathanamthitta & Alappuzha 2017 
• Sector wise distribution of Hazardous waste handling units in Kerala
  

 

 

 

4. Non-hazardous Wastes: Non-hazardous wastes are defined as substances safe to use commercially, industrially, agriculturally or economically. Some of the non-hazardous wastes produced are from the food processing plants, cotton mills, paper mills, textile mills and sugarcane industries. Other non-hazardous wastes includes paint, oil, antifreeze, buffers, salts etc. 

 

1. Municipal Solid Waste

 

Status of Generation, Collection and Treatment Systems in Kerala

 

                 Kerala is a state considered to be having a developed modern society. The consumption of more resources results in the generation of more waste. All types of waste including solid, hazardous and biomedical waste generation in the state are more compared to other states in the country. There is a series of actions initiated at National and State level abate the problems arise due to the wastes, particularly the pollution problem. Solid waste generation is mainly due to industrial and domestic activities. The waste generated due to industrial activities is of hazardous as well as non-hazardous nature. The solid waste generation due to domestic sources, the garbage, is very high in the State. The biomedical wastes are generated from all health care institutions. The responsibility of collection, treatment and safe disposal of all types of solid wastes rests with the generator.

 

Generation Status 

 

                 One of the fastest growing economies in the world, India contributes nearly seven percent of the GHG emissions in the world and ranked third after China and US in GHG emission. The State of India’s Environment Report 2023 published by the Centre for Science and Environment warns that four years and 11 months is the average duration of life lost to air pollution in India; over 30,000 water bodies are encroached in the country and India is generating 1.5 lakh tons of Municipal Solid Waste (MSW) every day, more than half of which is either dumped in landfills or remains unattended.

 

                   Kerala, with a total population of 3.34 crore, urban population of 1.59 crore (47.70 per cent) and annual urban population growth of 6.50 per cent, has been urbanizing at a rapid pace. The total solid waste generation in Kerala is estimated at 3.70 million tonnes annually, of which 2.17 million tonnes (59 per cent) are contributed by Urban Local Bodies (ULBs). Of the total waste generated in the State, the share of biodegradable and non-biodegradable waste is at 69 per cent and 31 per cent respectively.

 

Waste Management

 

            Sanitation and waste management have become pressing challenges for the State, particularly in the context of expanding urbanisation. The absence of effective mechanisms for processing, recycling, or disposing of waste, would severely pollute the environment and raise the risk of exposure to various diseases. Recognising the profound impact of waste management on the State’s development prospects, the Government of Kerala has firmly resolved to address waste management issues in the State on a war footing. The Government has devised multiple strategies at both the State and local levels to tackle this problem.

 

                 Apart from State-wide campaigns and initiatives, waste management has been integrated into the Plans of LSGs. Central and State-sponsored programmes and schemes concerning waste management are executed through LSGs. The nodal agency of this endeavour is the Suchitwa Mission, which plays a crucial role in developing implementation strategies and providing technical support to the State Government and local authorities for the formulation and execution of solid and liquid waste management policies and projects. The scientific processing and disposal of waste including the development of infrastructure for collection, storage, segregation, transportation, processing and disposal of MSW is an obligatory duty of the ULBs. Currently, the waste management system in the State focuses on the citizens’ responsibility to manage biodegradable waste at source, under the campaign ‘My waste, my responsibility’, thereby instilling a sense of ownership and duty with regard to waste management.

 

               In Kerala, a majority of the bio degradable waste is treated at households, institutions and at community-level centres. With the proposed projects during the current year for setting up source-level waste management at households and institutions, waste treatment capacity has been further increased. Non-biodegradable waste is collected from the doorsteps by Haritha Karma Sena units and other partner collection agencies. This non-biodegradable waste collected from households and other sources is temporarily stored in Material Collection Facilities (MCF) and Mini MCFs operated across the state.

 

             Solid waste management in the State has improved to a great extent during the period 2022-23. Details of Municipal Solid Waste (MSW) generation and treatment are shown in below. MSW treatment was 52 per cent in 2019-20, which has increased to 93 per cent in 2022-23.

 

 

 
                  The Haritha Karma Sena Self-Help Groups (SHGs) have played a pivotal role in collecting and segregating waste. The Malinya Muktam Nava Kerala campaign launched in March 2023 with the aim of making Kerala a completely garbage-free State by 2024 has made remarkable progress in the State. There are 1,236 Material Collection Facilities (MCFs), 16,096 Mini MCFs and 166 Resource Recovery Facilities (RRF) centres in LSGs across the State. Specific interventions for the disposal of special wastes such as construction waste, meat waste, hair waste, domestic, medical/sanitary waste etc. are also in progress. A total of 592 LSGs have implemented Harithamitram App, an online monitoring system to monitor the collection of non-organic waste. Haritha Karma Sena provides door-to-door collection services to 7.5 lakh establishments within Kerala. A total of 34,557 Haritha Karma Sena members have been deployed for doorstep collection of non-organic waste, and they are working in LSGs in the State. About 83 tourist destinations are being converted into green tourism destinations. A total of 7,326 institutions have been selected for conversion to green institutions.

 

Suchitwa Keralam (Rural and Urban)

 

                  Waste Management in urban and rural areas is through schemes funded by the State Government and implemented by Suchitwa Mission, the technical arm of the Department of LSG, which is responsible for evolving implementation strategies and policies in the sectors of sanitation and management of various solid and liquid waste. Suchitwa Keralam also involves awareness campaigns to promote scientific waste management practices by the public with the aid of audio-visual and print media.

 

                   Under the Suchitwa Keralam (Urban) scheme, 448 portable biogas plants were installed in Sultan Bathery and six Take a Break Projects were completed in Panoor, Kattapana, Cherpalassery, Neyyattinkara, Chavakkad, and Erattupetta Urban Local Bodies during the year 2022-23. Furthermore, pre-monsoon cleaning initiatives were carried out in five corporations and 82 Urban Local Bodies (ULBs).

 

• Kerala Solid Waste Management Project (KSWMP)

 

• Waste Management in Urban Local Bodies

 

2. Agricultural Waste

 

               India being an agro-based country, about 620 million tons of agricultural waste is generated every year. Since the biomass from the agricultural waste is available in a massive quantity, it has become an indispensable need to utilize these wastes as an alternative source of energy. Improper management practices like dumping of agricultural waste and burning down a barren land in open fires to clear off the agricultural waste pose serious environmental issues. These practices also generates wide number of toxic pollutants (N2O, SO2, CH4 and smoke) that affect the atmosphere at global scale. The rate of acceleration of agricultural waste generation is observed to strongly correlate with the emission of GHG, black carbon and CO2. Based on the global perspective of resource management, education and awareness in the field of waste management is in huge demand. Awareness programmes on these emerging issues could also improvise the regulation of agricultural waste management and lessen its possible health and environmental risks (Generation and Management of Agricultural Waste-Worldwide View by Iaithrangmon Buam and Nazneen Hussain).

 

                Kerala’s contribution to the total meat production in the country is 4.84 per cent in 2022-23 (Basic Animal Husbandry Statistics 2023). Species-wise meat contribution shows that 51.14 per cent of meat production in the country is contributed by poultry in the year 2022-23. In Kerala, majority of the meat is produced from cattle with 42.92 per cent in 2022-23.

 

GOBAR DHAN(Galvanizing Organic Bio-Agro Resources DHAN) Scheme

 

                     GOBARdhan, an integral component of SBM (G) launched on April 2018, is intended to manage biowaste including animal waste, kitchen left overs, crop residue and market waste into biogas. Until September 30, 2023, 40 large-scale community level bio-methanation facilities under SBM (Gramin) have been completed and have started functioning. The other 13 are in various phases of implementation.

 

3. Hazardous Wastes

 

                  Rapid industrialisation has resulted in the generation of large quantity of wastes, both solid and liquid, in industrial sectors. Despite requirements for pollution control measures, these wastes are generally dumped on land or discharged into water bodies, without adequate treatment, and thus become a large source of environmental pollution and health hazard. According to the National Inventory report India has generated about 15.66 million metric tons (MMT) of hazardous wastes during 2022-23 and 83,682 hazardous waste generating units have been reported.

 

                In Kerala, there are 2186 hazardous waste generating units, of which only 957 units (i.e. 44%) have submitted annual returns for the year 2022-23. The details on the generation and management of HW is as given below: