【Municipal solid waste management in Asian Cities】
Developing countries in Asia have some similarities in their municipal solid waste management (MSWM), waste composition and its characteristics. Estimates show that many cities in developing countries allocate 20–50% of their annual budget for MSWM, even though 30–60% of all urban municipal waste (MSW) remains uncollected and <50% of the population is served. The composition of MSW in developing Asia is dominated by organic waste and collection is often done without proper waste separation at source. The most common existing treatment method is landfill, as it remains the cheapest and easiest way of disposing of the MSW. However, most landfills in developing countries are poorly designed and maintained, effectively turning into open, unsanitary dumpsites.
The improper MSW collection and treatment contribute severe public and environmental health issues, including the global warming since organic waste is the main source of methane gas emissions through open dumping and landfill disposal. Thus, converting this high level of organic waste into resource recovery systems presents a sizeable untapped potential for extending the life of landfills, creating economic and environmental benefits, and ultimately reducing the pressure on municipalities in developing countries to manage the ever-increasing complexity of MSWM.
The potential of composting in municipal solid waste management
Figure1shows the percentage of MSW composition in six Asian countries. It shows that over 50% of MSW generated in these countries is organic waste. Further, MSW in developing countries is characterized by a significantly higher density and moisture, mainly organic waste with low caloric values (an average 700–1,000 kilocalories). Technically, high-moisture waste caused by the high percentage of organic waste makes it more suitable for biological treatment rather than thermal treatment. Moreover, due to this particular waste characteristic, integrated waste management involving composting is more energy efficient and has lower environmental impact.
Municipal waste compositions in Sri Lanka, Bangladesh, India, Thailand, Indonesia and PR China
Developing countries in Asia generally practice two biological treatment methods for organic waste management, such as aerobic composting and anaerobic digestion (AD). The AD method allows both material and energy recovery. The output of material recovery is compost fertilizer and the outputs of energy recovery are electricity and heat. Though AD plants are getting more popular due to these two benefits, they are highly sensitive towards input quality. Thus, AD technology has been commonly used in Asia to treat animal manure, kitchen and agricultural waste because of the uniformity and purity of organic content.
However, some attempts to apply this technology to treat MSW have not been so successful in many Asian cities where segregation of waste at source is poor. Moreover, the rate of implementation is hindered by the high up-front investment, maintenance costs and technical skill requirements. These failures can be seen in Delhi, Bangalore, Luck now and other cities in India. Similarly, municipal waste AD plants in China also faced problems and operational difficulties.
Generally, leaves and branches will be incinerated or compost, but burning these organic wastes not only generate air pollution but also waste the organic matter inside.Traditional compostuse microbial to decompose the organic matter, and it usually takes about 2~3 months to complete, which waste a lot of time and space. Rapid Treatment Technology may be the key to solve the problem of organic waste recycling for thousands of years. Rapid Treatment Technology can be applied in the processing of organic wastes including agriculture, forestry, fisheries, livestock husbandry, organic wastes and the cause of organic wastes, etc。
Composting-free technology combines physical, chemical and biological systems to accomplish economical, fast, efficient, and zero pollution technology. The major marketing benefits is that products of this Composting-free technology can be sold as agricultural applicants, as fertilizer, or as animal feed, which will reduce production cost while increasing farmer‘s income.
Prospects for environmental protection and integrated agriculture：
Composting-free technology rapidly treats organic waste with zero pollution. All kinds of organic wastes can be successfully treated with modified devices to suit all conditions. Composting-free technology is suitable and adaptable to all kinds, stages and capacity of organic waste.