In fact various industrial units are already working on small scale in private sector which recycle various types of items available and collected from domestic and industrial wastes. The domestic waste can be separate as organic and inorganic which can be further separated as bio-degradable and non-biodegradable.
The biodegradable is very conveniently converted into manure. Whereas non-biodegradable can be processed by idustrial units (like polythene and plastic).
The paper waste is converted into paper board on very large scale and agricultural waste is converted into bio-gas and manure.
The inorganic substances can be separated as metal, glass, etc. The metals like iron, aluminium, zinc etc., are recycled to make iron rods, castings, utensils etc., by many industries located all over India. Broken glass is again melted and used for making new items.
A housewife can help in recycling of various types of waste by separating different types of item and selling them as scrap.
Various types of uses of such scrap and by products have been described in subsequent paragraphs of this chapter. Several hundred people are directly engaged in collection and processing (by recycling methods) of all types of domestic and industrial wastes.
Community waste is recycled to get manure and industrial waste like FLY ASH from coal grid power station is used in making cement, light cement and concrete, ground improvement materail, asphalt filters, compost for right soil potash fertilizer, rockwool, glass wool, deodorant, sewer treatment material, blocks for civil engineering.
Fly ash obtained from different industries differs in its properties because different types of coalis used in this, also different types of coal generate fly ash having different particle size, shape and chemical composition and so when mixed with the different substances, it produces variable products.
Use of fly ash for making bricks has following advantages:
(a) For hardening (heating) the bricks has following is required and thus affects one third of saving in cost of bricks,
(b) hardening of bricks takes less time and simple kilns are required for the process,
(c) fly ash is cheaper;
(d) being waste material of coal can be beneficially utilized which otherwise would prove an environmental hazard;
(e) fly ash is also used in poultry industry;
(f) fly ash has been used for making insulating castable refractory material. The castable refractory material is made by mixing fly ash with plastic, clay and saw dust. This castable material is used in ceramic industry where 50% of the energy utilized in ceramic making is saved.
Discarded and used garments are not only used by poor but also used for providing raw material for hosiery industry and for making blankets, etc.
The waste materials can also be used for making decorative articles. One such example of reuse of waste material for decorative purpose is seen in the Rock Garden of Chandigarh where materials discarded by the society have been beautifully used.
Cow dung and sewage are being extensively used for making biogas for rural masses. The residual substance is very effectively used as manure.
In India garbage is collected and sorted out by rag pickers and thus collection of garbage generates employment. In fact in India waste paper, empty bottles, rags, etc., have a big market. Utilization of waste contributes directly or indirectly to economic development.
For instance because of increased cultivation of paddy in the country, huge quantities of paddy biomass are available which can be used as cattle feed, manure, fuel, packing and thatching material. Likewise many useful products of great value can be prepared from different types of waste material. Re-cycling and re-cycling of agro-industrial waste, wood and forestry residues, animal residue will significantly contribute for economic development, power generation, environment resource conservation, employment generation and provision of basic necessities of life.
Reclaimed articles like scrap ferrous, non-ferrous metal, paper, glass, tyres, textiles, used oils, discarded furniture, cars etc. are reusable materails for some small scale units.
Non-burnable garbage is separated, melted and pre-fabricated into the new design articles. Iron and Steel scrap is recycled to make articles like spoons, laddles, etc. by smaller casting units.
The lead is being recycled to the extent of 74% as the old batteries are being bought back by the manufactures for making new batteries.
Recycling aluminium scrap into making aluminium articles is well known. Recycling of aluminium beverage can saves about 90% energy that is needed to produce aluminium from its ore. Moreover, it reduces littering and generates employement.
Pesticide containers are collected and returned to the factories for reuse.
Depletion of resources occur more on using virgin materials and not from the use of recycled materials.
Implementing the "Take-Back" scheme can effectively halp in reducing the cost of the article. The producers should take-back all the packaging material including empty card board boxes and reuse them. Carbon char can be used as charcoal substitute.
Thus it can be very conveniently visualized that there are immense possibilities and benefits of recycling the waste. India being a developing country needs to adopt a national programme to minimise the waste both in production and use.
Also Government should enforce its programme through laws to collect information about quality, season wise availability, collection classification, disposal so that the discarded waste of one factory can be purchased and used by another factory can be purchased and used by another factory, e.g., molasses from sugar factories is purchased to produced alcohol.
The building material waste are frequently utilized as filling material for pits and low-lying areas or filling the empty spaces around foundations or as filling material for roofs before final flooring.
The list given above depicts the extent and nature of the waste available in the country. Some of the waste being recycled for beneficial uses like: (a) Paper waste is recycled to get card board. (b) Waste from sugar industry is used to make construction material. (c) Aquatic waste is recycled into food for fish, ducks, donkeys, pigs, and (processed food for cattle), fertilizer, biogas, pulp and paper.
To achieve effective benefits from waste-recycling, various materials like organic matter, plastic, metallic item etc. should be properly sorted out and efforts should be made to make them available to factories and manufacturing units for using them further.
In above paragraphs this been outlined in brief. But it also is a fact that in India alone several hundred people are engaged in this network directly or indirectly. But whole system is almost unorganized and operated by private sector.