Plastic,with its exclusive qualities is now a serious worldwide environmental and health concern, essentially due to its non-biodegradable nature. More than 50% of the plastic waste generated in the country is recycled and used in the manufacture of various plastic products.
Dioxin is a highly carcinogenic and toxic by product of the manufacturing process of plastics. Burning of plastics, especially PVC, release this dioxin and also furan into the atmosphere.
Plastics are so versatile in use that their impact on the environment is extremely wide ranging. Careless disposal of plastic bags chokes drains, blocks the porosity of the soil and causes problems for groundwater recharge. Plastic disturbs the soil microbial activity. Plastic bags can also contamine foodstuffs due to leaching of toxic dyes and transfer of pathogens. In fact, a major portion of the plastic bags i.e. approximately 60-80% of the plastic waste generated in India is collected and segregated for recycling. 20-40% remains strewn on the ground littered around in open drains.
Designing eco-friendly, biodegradable plastics are the need of the hour. Through partially biodegradable plastics have been developed and used, completely biodegradable plastics have only recently been developed.
The various source of generation of plastics wastes include: Household such as(Carry bags, Pet bottles, Containers, Trash bags), Health and Medicare(Disposable syringes, Glucose bottles, Blood and urine bags, Intravenous tubes, Catheters, Surgical gloves), Hotel and Catering (Packaging items, Mineral water bottles, Plastic plates, cups, spoons) Air/Rail Travel(Mineral water bottles, plastic plates, cups, spoons, plastic bags).
Characterization studies indicate that MSW contains large organic fraction (30-40%), ash and fine earth(30-40%), paper(3-6%) along with plastic glass and metal( each less than 1%), calorific value of refuse ranges between 800-1000 kcal/kg and C/N ratio ranges between 20-30% . The collection bin and implements used in various cities are not properly designed. It has been observed that community bins have not been installed at proper location . This has resulted in poor collection efficiency Lack of public awareness has made the situation worse. Various types of vehicles are used for transportation of waste to the disposal site. However, these vehicles are not designed as per requirement. In many urban centers, proper garages are not provided for the vehicles for the protection from heat and rain. Preventive maintance system is not adopted and as a result the life of the vehicle is reduced. Many of the vehicles used for transportation of waste have outlived their normal life.
Waste is disposed off in low-lying areas without taking any precautions and without any operational control. Solid waste workers handle the waste without any protective equipment and are prone to infection.
The waste characteristics are expected to change due to urbanization, increased commercialization and standard of living. The present trend indicates that the paper and plastics content will increase will the organic content will decrease. The ash and earth content is also expected to decrease mainly due to an increase in the paved surface. Although the organic content is expected to decrease, the material will still be amenable to biodegradable and the calorific value will continue to be unsuitable for incineration.
In keeping with the present practices and estimates of waste generation, around 90% of the generated wastes are land filled requiring around 1200 hectare of land every year with an average depth of 3 m. Due to rapid urbanization, prevailing land use regulation and completing demands for available land, it is desirable that adequate land be earmarked at the planning stage itself for solid waste disposal. The larger quantities of solid waste and higher degree of urbanization will necessitate better management involving a higher level of expenditure on manpower and equipment.
