Waste+Management

Back to Main Body

Recycling is the process of producing new products from used material in order to protect our environment. The objective is to create a broad and sustainable recycling system for the city of Island, to shape a green image, and to enhance the quality of life for its residents. **Figure: 1 Material flow diagram for Recycling in the City** Usable products for consumers are manufactured by number of different industries from the extraction of natural resources in the city. The used products become waste. The waste is collected and then 40% of waste is dumped directly into landfill or it is first burned and then dumped and rest 60% recyclable materials are collected for recycling to produce new useful products. The recyclable products can reduce the input of new raw material and it also reduces the solid waste. This process is occurred inside and outside of the city boundary. The waste material flow into the city also shows the number of people work in the recycling and waste system. All arrows and boxes show the requirement of labor. Numbers of people are required for collecting waste from various resources such as industrial and residential wherever the material goes, whether recycling or landfill.

=
There are various number of recycling systems which can be implemented in island city in order to collect recyclable material from the general waste stream such as "drop-off centers", "buy-back centers" and "curbside collection"( **Curbside Collection, 2011)** Curbside collection is a service provided to households, typically in urban and suburban areas, of removing household waste. It is usually accomplished by personnel using purpose built vehicles to pick up household waste in containers acceptable to or prescribed by the municipality (Cutting-Edge-Recycling project in the City of Arad, 2011). =====  It is estimated that curbside collection is a better recycling system as compared to other system to be pursued because it would be convenient for the both residents and waste collecting authorities to dispose and collect the waste in front of residents’ houses. Also, it results purer waste stream recovery with higher sell value. Following are various numbers of recyclable materials: **6.1.** Plastic **6.2.** Glass **6.3.** Waste water **6.4.** Metal Food and Beverage Containers **6.5.** Paper Let’s suppose that to establish the composition of recyclable material in the waste stream in island city, a waste was estimated and given as follow:
 * **S#** || **Recyclable Material** || **Percentage Generated** ||
 * 1 || Plastic || 8% ||
 * 2 || Glass || 20% ||
 * 3 || Waste || 40% ||
 * 4 || Metal containers || 7% ||
 * 5 || Paper || 25% ||

Figure:2 Pie chart for waste composition

Recycling System for Plastic, Paper, Glass, and Metallic Containers
Figure: 3. Recycling System = =

The waste water can be treated by number of following steps:
** Coagulation/flocculation ** - Raw water from terminal reservoirs is drawn into mixing basins at treatment plants where alum, polymer and sometimes lime and carbon dioxide are added. This process causes small particles to stick to one another, forming larger particles. ** Sedimentation ** - Over time, the now-larger particles become heavy enough to settle to the bottom of a basin from which sediment is removed. ** Filtration ** - The water is then filtered through layers of fine, granulated materials — either sand, or sand and coal, depending on the treatment plant. As smaller, suspended particles are removed, turbidity diminishes and clear water emerges. ** Disinfection ** - To protect against any bacteria, viruses and other microbes that might remain, disinfectant is added before the water flows into underground reservoirs throughout the distribution system. **Corrosion Control**-PH is maintained by adding alkaline substances to reduce corrosion in the distribution system.



**6.2. Metal Food and Beverage Containers**
= = Today it is cheaper, faster and more energy-efficient to recycle aluminum than ever before. The process of recycling aluminum cans in the city is described below; **Step#01** Aluminum cans are collected at residential drop-offs and by municipal pick-ups. Once cans arrive at the MRF (Material Recovery Facility) they will be sorted using a device called an eddy current. The eddy current briefly electrically charges they can cause it to repel from the device off a sorting line into an awaiting bin. After, they condense the cans into highly dense, 30-pound briquettes or 1,200-pound bales and ship them off to aluminum companies for melting. **Step#02** At the aluminum companies, the condensed cans are shredded, crushed and stripped of their inside and outside decorations via a burning process. Then, the potato chip-sized pieces of aluminum are loaded into melting furnaces, where the recycled metal is blended with new, virgin aluminum. **Step#03** The molten aluminum is then poured into 25-foot long ingots that weigh over 30,000 pounds. The ingots are fed into rolling mills that reduce the thickness of the metal from 20-plus inches to a sheet that is about 10/1,000 of an inch thick. **Step#04** This metal is then coiled and shipped to can makers, who produce can bodies and lids. They, in turn, deliver cans to beverage companies for filling. **Step#05** The new cans are then ready to return to store shelves in as little as 60 days, only to go through the entire recycling process again.

**6.3.** **Paper Recycling**
= = **Pulping:** Adding water and applying mechanical action to separate fibers from each other. **Screening:** Using screens, with either slots or holes, to remove contaminants that are larger than pulp fibers. **Centrifugal cleaning:** Spinning the pulp slurry in cleaner cause materials that are denser than pulp fibers to move outward and be rejected. **Flotation:** Passing air bubbles through the pulp slurry, with a surfactant present, causes ink particles to collect with the foam on the surface. By removing contaminated foam, pulp is made brighter. This step is sometimes called de-inking. **Kneading or dispersion:** Mechanical action is applied to fragment contaminant particles. **Washing:** Small particles are removed by passing water through the pulp. **Bleaching:** If white paper is desired, bleaching uses peroxides or hydrosulfides to remove color from the pulp. **Papermaking:** The clean (and/or bleached) fiber is made into a "new" paper product in the same way that virgin paper is made. **Dissolved air flotation:** Process water is cleaned for reuse. **Waste disposal:** The unusable material left over, mainly ink, plastics, filler and short fibers, is called sludge. The sludge is buried in a landfill, burned to create energy at the paper mill or used as a fertilizer by local farmers.

**6.4.** **Glass Recycling**
= =

=
Glass is sorted at material recycling facility into various colors, mainly Flint (clear glass), Green glass, and Brown / Amber glass. Glass is then sold to glass processors to be cleaned and crushed. The glass that has been processed is now known as cullet and is ready to be used in producing new glass. =====

=
The waste crushed plastic transferred by conveyor belt to on washing type crushing station where it is washed and crushed into further smaller pieces. After washing and crushing the plastic it is into smallest pieces, the water is removed by squeezing process and this process is repeated two times. Once the total impurities are removed from the plastic the next step is to crush the plastic into further smallest particles in order to do blowing and cyclone operation. Now the plastic is ready for extrusion process. After extrusion process it is cooled, dehumidified, cut into small pieces. Finally it is stored into big bags and transported to other manufacturing companies for making other useful plastic products. =====

On the basis of all above estimated information it is concluded that 60% of the waste can be recycled by installing above industries and rest 40% waste can be burned within the city in order to produce energy from that. Also it it would be more beneficial to install most of those manufacturing industries which produces products from the recycled material such as: glass, paper, plastic, etc.