Waste management: what are the main types of waste collected ?

Waste management is associated with technological and social human development where the compositions of various type of wastes have changed over time, with the expansion of the industry being directly linked to waste resources and waste materials, such as nuclear technology and plastics. It is widely recognized that waste materials can be a valuable resource, whereas there is debate as to how this value is best realized, where some waste apparatuses have economic worth and can be recycled once correctly recovered.

Fig 1: Construction waste

Solid waste includes all items that people either intend to dispose. Many items can be considered as waste e.g., home rubbish, sewage, wastes from different manufacturing activities, discarded cars, old televisions, old paint containers, the waste form garden etc. Consequently, all our daily activities can lead to rise a large variety of different wastes arising from different sources.

Scientists are looking for alternative materials for highway construction such as soil, aggregates, bitumen and sand because of the gradual decrease of these materials due to their presence in nature and the permanent use, which cases that the cost of extracting a good quality of these materials increase. industrial waste product is one such category and if these materials can be properly applied in highway construction, the pollution and disposal problems may be partly concentrated.

Types of waste

The major categories of waster are:

• Municipal waste
• Agricultural waste
• Hazardous waste
• Commercial waste
• Sewage sludge
• Industrial waste
• Mines and quarries.
• Construction and demolition waste

These categories will be discussed in this post.

1.    Municipal waste

Offices, schools, shops, households and hotels are the main generators of municipal waste which mainly consists of plastic, paper, food waste, metal, glass and rags. However, construction debris is often included in the collected waste. Also, municipal waste contains a small quantities of hazardous waste as: electric bulbs, car parts, batteries and chemicals.

Fig 2: Composition of municipal waste

The municipal waste is not transported with water as sewage because of its heterogeneous mixture of various kinds of wastes, and it may include non-putrescible waste like paper, glass, rags etc., called rubbish and bio-degradable food wastes which called garbage.

2.    Agricultural waste

Considerable amounts from agricultural production are resulting from agricultural production, some of it is recycled into the agricultural production as fertilizer, while large amounts remain unused, and in many instances pose a disposal problem. Waste from agricultural production can be utilized as fuel for power and heat production with efficient collection systems. Moreover, Dispose the waste by the unorganized burning in the fields is such a dangerous and polluting method, also wasting a useful and great source of energy, which is the waste.

Agricultural waste is mainly composed of organic wastes (Spent mushroom compost, soiled water and silage effluent and animal excreta in the form of slurries and farmyard manures) and waste such as plastic, scrap machinery, pesticides, fencing, waste oils and veterinary medicines.

Agricultural waste is caused due to poor pesticide application, over grazing, irrigation water, fertilizers. It’s also includes paddy husk, animal waste, straw, coir dust and biogases as well as the waste from the wood or timber industry, which includes off-cuts, sawdust and charcoal.

Composition of agricultural waste:

• Packaging
• Silage plastic
• Oils
• Net wrap
• Batteries
• Old fencing
• Building waste
• Scrap metal

Special wastes are that type of waste which has dangerous properties and is subjected to extra controls to protect environment and health of humans; examples of special wastes includes: Roofing materials which contains asbest, Chemical fertilizers, Waste oils from farm machinery, Infectious waste from animals, Electrical equipment containing cathode ray tubes.

3.    Hazardous waste

Hazardous waste carries potential threats to public health also for the environment. The Asian and Pacific Region is consuming substantial quantities of toxic chemicals and creating a large amount of hazardous waste according to quick development in industry, agriculture, commerce, hospital and healthcare facilities. There are about 110, 000 types of toxic chemicals commercially available nowadays.

These wastes may be found in many physical conditions such as solids, gaseous or liquids. A hazardous waste cannot be disposed of by common means like other products of our everyday lives, so its a special type of waste. Treatment and solidification processes might be required Depending on the physical state of the waste.

4.    Commercial waste

Commercial places like shops, restaurants, markets, etc. generate commercial waste which have characteristics similar to the domestic waste as described before. More and more solid wastes are produced from the commercial places. Some examples are:

• Construction sites produce many debris of broken bricks, stones, cement, rock, waste iron and other metals etc. These are called as rubble, other building construction materials are asbestos, plastics pipes, insulating materials, broken electrical goods, etc.
• Market place produces a lot of rubbish, garbage and food waste and thrashes materials etc. Broken fridges, air conditioners and coolers are generally found in market places.

5.    Sewage sludge

The waste products of a society has been developed into a method of disposing of the society’s wastes has now been modernized and replaced by a system, in which these are mixed with appropriate quantity of water and carried through closed pipes under the conditions of gravity flow. This mixture of water and waste products is called sewage.

Domestic sewage consists of waste coming from bathrooms (liquid waste), urinals, kitchens and wash basins, etc., of the residential, industrial or commercial buildings, where this sewage is extremely foul because it includes human excreta in it.

Industrial sewage consists of waste originating from industries (liquid waste), such as paper making and Brewing etc., the quality of sewage depends on the type and the amount of chemicals they are using in the industry.

6.    Industrial waste

Industry is one of the most important factors that measures the development of a country’s economy, through the founding plants and industries. However, the waste or by-products discharged from them are strictly devastating to the environment consists various kind of pollutant which contaminate the surface water, ground water and soil. There are a number of factors the waste are not safely treated. One of them is due to the lack of highly efficient and economic treatment technology.

Environmental pollution is the main problem connected with rapid industrialization, growth and rise in living standards of people. For developing countries, industrialization was must and still this activity very much demands to build self dependent and in increase the nation’s economy. However, expansion and development the manufacturing process has also caused serious problems relating to environmental pollution. On the other hand, with increasing demand for raw materials for industrial production, the non-renewable resources are decreasing everyday. Therefore, efforts are to be made to control to continous increase in the pollutionout of the disposal of wastes by conversion of these unwanted wastes into usable materials as raw materials to benefit from it for various uses.

7.    Mines and quarries

Waste from mines and quarries is one of the largest waste streams, because involves materials that must be removed to gain access to the mineral resource. As well as tailings remaining after minerals have been basically extracted from the ore. Some of these wastes are inactive and hence not likely to represent a important pollutant threat to the environment save for smothering of river beds and likely collapse if stored in large quantities. However, other parts, especially those generated by the non-Ferrous metal mining industry may comprehend large quantities of dangerous substances, such as heavy metals.

These effects can be extremely difficult and costly to address through helpful measures. Wastes from the mines and quarries industries have therefore to be appropriately managed in order to ensure in the stability of disposal facilities in long-term and to avoid any water and soil pollution arising from acid or alkaline drainage and leakage of heavy metals.

8.    Construction and demolition

Construction and demolition waste is generated in every construction site from the begining till it ends, such as highways and roads, buildings and excavation works, bridges, subway etc. It consists mainly non-bio degradable material such as concrete, plaster, wood, metal and plastics etc. Municipal stream took part in this.