Recycling, composting key to municipal waste management

Solid Waste Management (SWM) is a serious problem in India resulting from rapid urbanization, population explosion, changing lifestyles and modernization. This resulted in the generation of a large amount of municipal solid waste (MSW) from local urban bodies (ULB). About 72 million tons (MT) of solid waste (SD) is generated in the country, of which 43 MT is collected and only 12 MT of waste is treated.

About 31 MT of SW are dumped into the landfill without any treatment every day. SW production is expected to reach 165 MT per day (MTPD) by 2030 and 436 MTPD by 2050. If cities continue to dump waste at the current rate without treatment, it takes about 1,240 hectares of land per year to dump the waste generated throughout the country. Since the land resource in urban areas is limited and valuable, it is necessary to develop an action plan to minimize landfill needs.

Landfilling MSW generates a huge amount of leachate that can potentially contaminate groundwater and surface water, causing irreparable damage to precious water resources. Most ULBs adopt landfill as a solid waste disposal option. Unscientific landfilling contaminates groundwater, generates greenhouse gases like methane and hydrogen sulfide and causes foul odor nuisance in the area up to 2-3 km away.

This not only overburdens the scarce land resources of towns and cities, but also exacerbates the adverse health effects on human beings. The widespread agitation of the masses against landfilling in their neighborhoods is a well-known fact. On the contrary, if MSW are managed properly, they can be a valuable manure and a renewable energy source like biogas.

Karnataka State Pollution Control (KSPCB), a regulatory authority for waste management, is making substantial progress in the scientific management of MSDS by applying the rules of GDS, 2016. About 13,200 TPDs from SW waste is generated in the state of which 50-55% is wet/organic waste, 30-35% is dry waste and 10-20% is construction and demolition waste and inert waste. By 2031, Bangalore’s municipal SW generation alone will cross 13,000 TPD.

The KSPCB mandates door-to-door collection, segregation, transportation and proper disposal of SWs at all ULBs. Districts like Udupi and Mysuru have managed to achieve a high percentage of door-to-door collection, while districts like Kalaburagi, Kolar, Davanagere and Bengaluru have room for improvement. Some local organizations like Shivamogga and Kundapura have adopted strategies such as pipe composting, community composting, etc. for efficient management of wet separated waste.

Wet waste can be better managed through aerobic composting, vermicomposting and anaerobic digestion or biomethanation. Dry waste is best managed by manufacturing waste-derived fuel (RDF), palletizing, incineration and thermal pyrolysis and the final option for waste disposal should be sanitary landfill. Composting is the scientific method of producing manure by breaking down organic waste. Manure contains essential plant nutrients and micronutrients, which can be used as fertilizer. If 2,780 TPD of organic waste is composted, it can produce 556 TPD of compost, which corresponds to an income of around Rs 27.8 lakh per day. UWBs should seriously consider the economic viability of waste management and achieve higher conversion rates of organic waste to compost and implement advanced composting methods such as vermi-composting, co-composting, composting at inoculum base, etc.

Organic waste

At present, out of the 6,145 TPD of wet waste generated in Karnataka, only about 3,366 TPD is converted into 672 TPD of compost, which is sold to farmers at a nominal price of Rs 5 per kg, in coordination with the Ministry of Agriculture. Districts like Dakshina Kannada, Shivamogga, Mysuru, Belagavi and Dharwad generate over 20 TPD of compost from organic waste. Compost generated in Ballari, Raichur, Yadgir, Gadag, Kodagu, Chamarajanagara, Mandya and Chitradurga is only 5 TPD. Only 55% of wet waste is composted in the state and there is plenty of room for improvement.

Karnataka generates about 3,476 TPD of dry waste. Of this total, 515 TPDs are recycled and 215 tons are converted to RDF and 117.88 TPDs are sent to cement kilns for co-processing in cement industries as an energy source. However, the remaining amount of 2628.12 is dumped into the landfill without converting it into a useful energy resource. RDF is produced from dry waste generated from domestic and commercial activities that includes biodegradable and non-biodegradable combustible materials. RDF with a calorific value greater than 2,000 Kcal/kg would constitute a good alternative source of energy in cement works or would be incinerated in waste-to-energy plants. Further, in the “Guidelines on the Use of RDF in Various Industries” of the Ministry of Housing and Urban Affairs, RDF has been priced at an indicative price of Rs 600 to Rs 2,400 per ton, which can be a continuous source of income for ULB.

Major districts such as Mysuru, Shivamogga, Dakshina Kannada, Belagavi, Bagalkote, Vijayapura, Uttara Kannada and Kalaburagi ULBs recycle more than 20 TPDs of dry waste. Local bodies in rural Bengaluru, Davanagere, Chikkaballapura, Mandya, Chamarajanagar, Hassan, Chikkamagaluru, Udupi, Yadgir, Raichur and Koppal recycle less than 5 TPD of dry waste. Kolar, Bengaluru Urban, Tumakuru, Uttara Kannada, Bidar, Belagavi and Kalaburagi have taken steps to convert dry waste into RDF. BBMP has proposed four major projects on behalf of the “Waste-to-Energy” initiative, which are still in their early stages.

Poor waste management has led to the creation of nearly 215 landfills across the state. Apart from 10 dumps in Bengaluru, many illegal dumps are created in and around the city. Considering the fact that resources for waste management and disposal methods are scarce, the effective scientific management strategy of MSW must necessarily be oriented towards resource recovery, thus making waste a valuable component. The waste management hierarchy could be optimized by adding the “recover” option – reduce, reuse, recycle and recover.

Economic revenues from sorting waste and converting it into usable materials should also increase the income of urban local communities. It is high time to make collective efforts for the implementation of waste recycling and composting activities in order to achieve sustainability in the economic and ecological management of waste.

(The author is a member-secretary, KSPCB)

Melissa C. Keyes