RECYCLING OF WASTES

Asst. prof. Dr. Qasim M. Shakir
University of Kufa/Faculty of Engineering
e-mail:qasimm.alabbasi@uokufa.edu.iq

1-Definition
Recycling: is the process of separating wastes after collection Then processing of which are recyclable and converting it into new products. The relevant institutions have developed three waste management facilities as shown in Fig. (1); minimizing waste by reusing what can be used and recycling the residual. The materials that can be recycled include glass, paper, plastic and various metals.

Fig.(1) components of recycling process

For example, used paper, cardboard, egg layers, and old books of various kinds can be recycled into similar paper products, and re-manufacture old metal cans to provide new boxes for use in areas other than those related to cans And to recycle scrap metal to obtain new alloys that can be used in the manufacture of various products, as well as wood, plastic, glass, etc. Furthermore, gases can be reused as fuel and in industries such as sulfur oxides, nitrogen oxides and Carbon dioxide.
The process of recycle of gaseous, liquid and solid waste is an important part in green building philosophy. Thus, countries that have made steps in adopting such philosophy are increasingly interested in the recycling of waste. Fig.(2) shows a waste heap in one of the empty yards close to a market in Najaf city while Fig.(3) shows a container model developed by the municipalities of a country working according to the green buildings. The sorting process is automatic by the citizen himself.

2-History
The idea of recycling began during the First World War and developed remarkably during the Second world war, when countries were suffering from a severe shortage of some basic materials such as rubber, which led to the collection of these waste materials for reuse. Years later recycling has become one of the most important methods of solid waste management because of the many environmental benefits of this method. For many years, direct recycling by scrap producers was the primary form of recycling, but by the early 1990s the focus was on indirect recycling, which meant manufacturing waste materials to provide other products based on the same raw material.

3-Why has recycling become more important now?
It can be said that the problem of disposal of solid waste has become one of the most important environmental problems that the world suffers nowadays, as the quantities of solid waste are increasing day by day compared to the past days that can be attributed to the following:
1- Increased growth in Population.
2- High standard of living.
3- Industrial and agricultural progress without following the appropriate methods in the collection, transport and treatment of solid waste.
4- Increase the person consumption such as plastic, metal and glass containers.
5. Lack of environmental awareness among citizens.
6 – Lack of environmental legislation in the management of waste gas, liquid and solid.
4-The advantages of the recycling process
a. Conservation and protection of the environment
The continuous use of paper means cutting trees constantly, but when paper is repeatedly recycled. This will help to reduce deforestation along with the production of paper from sustainable trees (with rapid growth), thereby preserving forests. Because trees provide raw materials and improve air.
b. Reduce energy consumption.
The transfer of raw materials involves the use of energy. Processing of raw materials also requires a large amount of energy, while the recycling of partially processed materials consumes less energy. However, almost all recycling operations are more energy-efficient than the processes used for new materials.
c. Reduce air and water pollution(waste reduction).
Industrial waste is a major source of pollution today that is produced by the factories. In the case of the reuse of those products, instead of being manufactured from scratch, pollution can be reduced significantly. The disposal of waste by burning, causes significant damage to the environment and the use of atmosphere gases in useful industries (if available in commercial quantities) such as carbon dioxide, sulfur dioxide and others will help improve air water of rivers quality has a great impact on human health.

d. Mitigating global warming.
Recycling also preserves the process of incineration at minimum, minimizing waste generation. Transforming waste into useful and environmentally friendly products also helps mitigate harmful environmental impacts and reduces the burning of large quantities of waste that emit greenhouse gases at high rates such as Carbon dioxide, sulfur and nitrogen, which contribute to climate change and global warming.
e. Reduction of landfills.
Most non-biodegradable products are usually dumped worldwide in landfills. Since it takes years or decades of decomposition,. This leads to pollution environmental problems and pollution of water and surrounding areas, especially since disinfected rubbish can reach the sewers and water bodies as they can seep through the soil and contaminate them. Therefore, recycling reduces the amount of waste in land sites
f. Dissemination of environmental awareness.
Where people become more familiar with recycling and educated about its importance, are more environmentally aware and more involved in environmentally friendly activities. And helps to encourage citizens to participate in the preservation of the environment change the behavior of consumer consumption through the generalization and application of the idea of sorting waste and reduce and recycling
g. Generate revenue.
Germany declared lately, it is a waste-free country because German garbage companies re-manufacture all types of waste. The most important of which is the big profits are the paper, where paper towels and plastic return the raw materials for similar industries and iron waste electrical and food waste. The profits of these companies amounted to 100 billion dollars a year. It opened the door to the garbage companies to buy waste from Italy, Sweden and Norway.
h. Maintains natural resources
Recycling ensures the use of existing resources reasonably and sustainably and access to large supplies of raw materials for industry, this is one of the fundamental principles of sustainable development. it reduces the heavy use of raw materials. i.e.the existing natural resources can be left to be exploited by future generations without affecting current production. Without recycling old materials, raw materials must be extracted through mining and extraction. By making products from recycled materials rather than virgin materials, we reduce the need for logging, drilling for oil, and drilling for metals. Recycling prevents depletion of earth resources and recycled paper means reducing the number of trees cut.

i. Creates new jobs
Recycling reduces unemployment levels as it provides some jobs. The establishment of many recycling plants, leading to the establishment of a long chain of collection and delivery.
5-The disadvantages of the recycling process
a. More pollution and energy consumption.
Recycling of tons of waste requires transportation outside the cities, sorting, cleaning and treating them in separate plants, and may produce by-products that can contaminate air, water or soil. When more trucks are used to pick up recyclable products, air pollution will also increase.
b. Their products contain some contaminants.
For example, recycled steel used in buildings in some countries causes toxic poisoning by some harmful radiation. This obstacle is overcomed by strict qualitative control over the quality of products manufactured from the recycling process.
c. Increasing the cost of treatment and low-income jobs
The cost of recycling can be large if it is manual, since the assembly and sorting process will need many hands. The amount of materials that will be sorted over time will not provide a good margin of profit, All stages and involvement of the citizen in the development of containers dedicated to each type of waste and follow the methods of modern technology will help to increase the financial return of investment companies working on the recycling industry.
d. High initial costs
Recycling requires a large initial cost to build waste recycling units and associated costs such as purchasing various types of vehicles as well as media, courses and education for local people through the initiation of useful programs and educational seminars to make this a success.
e. Requires more rigorous implementation.
That recycling has a negative impact on health and the environment when it is not done properly. toxic wastes that are handled incorrectly can contaminate land, air and the environment. Therefore, strict implementation regulations must be followed. Recycling is always unhealthy and unsafe and provides a breeding media for contagious diseases. Harmful chemicals from these wastes can also be hazardous. Waste is in contact with water, these results in the formation of leachate that ends up polluting water resources, and drinking water.
f. Recycled waste products may not be durable.
The quality of products manufactured from recycled waste may not be good and will be less durable. Thus will be low in price.
g. Generally ineffective.
As mentioned above, recycling results in more pollution, higher energy consumption, and costly inefficient, making it less effective. In addition, demand for some materials increases by annual rate higher than that provided from recycling process
6-Some types of waste can be recycled:
Wastes that can be recycled consist of the following types:
1. Plastics: including water bottles, plastic bags, plastic casings, rubber bags, tires, etc.
2. Glass products that can be recycled include glass windows, containers and glass containers of various kinds
3. Paper: such as magazines, newspapers, books, envelopes, cardboard boxes, paper, and the result of the activity of the departments, institutions, schools, etc.
4. Metals: Such as iron and aluminum, waste resulting from industrial activity and metal cans of various forms.
5. Wood and fabrics: the output of old furniture, tree trimming, cleaning of gardens, waste cleaning palm trees etc.
6 – Gases: Such as carbon dioxide, because the large amounts of it emitted into the atmosphere contribute largely to exacerbate the phenomenon of warming.
7. Liquid waste: such as rainwater, domestic sewage, heavy water and motor vehicle oils.
8 – Wastes of demolition and construction activities: such as wastes of brick, ceramics, marble, clay tiles, crushed concrete, false ceilings, insulation layers, packaging, etc.
Fig.(4) shows the results of a study reported by one of the relevant associations about the solid wastes at the United States (% by weight). It can be seen that papers is the major constituent of the wastes. Fig. (5) shows several recycling factories and plants.